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  • DataBinding: 'System.String' does not contain a property with the name 'dbMake'.

    - by marcmiki
    Hi , i am a newbie at ASP.net and after using sqldatasource with a listview to insert and show results from an SQL server db i want to try using the LINQ datasource since it seems to be more flexible in codebehind. My problem is this: i droped a listview control to the page and i created the Linq datasource in codebehind with vb. the issue that i am having when i ..Select d.columms name i get the error system.string does not contain a property with the name "columname".. if i ommit the column name then its works fine.. the funny part is the d.count works fine but after that i get the error.. please see my code below: vb code Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load Dim rowsCount As Integer Dim showSearchForm As String showSearchForm = Request.QueryString("tab") If showSearchForm = "1" Then Dim db As New ASPNETDBDataContext() Dim q = From b In db.PassengerVehiclesTables Select b.dbMake rowsCount = q.Count MsgBox(rowsCount) lvMakes.DataSource = q lvMakes.DataBind() PnlPassengerVehiclesSearch.Visible = True ElseIf showSearchForm = "2" Then aspx code <asp:Panel ID="PnlPassengerVehiclesSearch" Visible="false" runat="server"> Search Passenger Vehicles Form.....<br /> <table style="width: 100%; border-style: solid; border-width: 1px"> <tr> <td> <asp:ListView ID="lvMakes" runat="server"> <LayoutTemplate> <asp:PlaceHolder runat="server" ID="itemPlaceholder" /> </LayoutTemplate> <ItemTemplate> <%#Eval("dbMake")%><br /> </ItemTemplate> </asp:ListView> </td> b.dbMake needs to work so that i can use Distinct ,, ia m using asp.net version:3.5 and IIS version 7.0 .. not sure what i am missing ,, but i did try alot of approaches,,1- checked the web.config file and it seems to have two assemblies and two namespaces for LINQ..2- used different databinding syntaxs,,and i searched a lot for the solution.. the last one i read the person ommited the name of the column,, i thought that wasnt the best solution.. also my dbMake column is comming up in the "intellisence" .. thank you in advance for your help..

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  • InteropServices COMException when executing a .net app from a web CGI script on Windows Server 2003

    - by Kurt W. Leucht
    Disclaimer: I'm completely clueless about .net and COM. I have a vendor's application that appears to be written in .net and I'm trying to wrap it with a web form (a cgi-bin Perl script) so I can eventually launch this vendor's app from a separate computer. I'm on a Windows Server 2003 R2 SE SP1 system and I'm using Apache 2.2 for the web server and ActivePerl 5.10.0.1004 for the cgi script. My cgi script calls the vendor's app that resides on the same machine using the Perl backtick operator. ... $result = "Result: " . `$vendorsPath/$vendorsExecutable $arg1 $arg2`; ... Right now I'm just running IE web browser locally on the server machine and accessing "http://localhost/cgi-bin/myPerlScript.pl". The vendor's app fails and logs a debug message that includes the following stack trace (I changed a couple names so as to not give away the vendor's identity): ... System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.Runtime.InteropServices.COMException (0x80043A1D): 0x80040154 - Class not registered --- End of inner exception stack trace --- at System.RuntimeType.InvokeDispMethod(String name, BindingFlags invokeAttr, Object target, Object[] args, Boolean[] byrefModifiers, Int32 culture, String[] namedParameters) at System.RuntimeType.InvokeMember(String name, BindingFlags invokeAttr, Binder binder, Object target, Object[] args, ParameterModifier[] modifiers, CultureInfo culture, String[] namedParameters) at VendorsTool.Engine.Core.VendorsEngine.LoadVendorsServices(String fileName, String& projectCommPath) ... When I run the vendors app from the Windows command line on the server machine with the exact same arguments that the cgi script is passing it runs just fine, so there's something about invoking their app via the web script that is causing a problem. This problem is likely security related because the whole thing runs just fine on a Windows XP Pro machine (both command line and web invocation). I actually developed my web script there and got it completely working there before I tried moving it to the Windows Server 2003 machine. So what's different about the Windows Server 2003 machine that would keep the vendor's .net app from being executed successfully by a web cgi script? Can I fix this problem somehow to make it work on my server or will the vendor have to make a change to their .net app and ship out a new version? I'm probably the only person in the world who is trying to execute this vendor's app from a separate program, so I hate to bother the vendor with the issue if there's a workaround that I can implement myself here on my server machine. Plus, I'm in kind of a hurry and I don't want to wait 4 or 6 months for the vendor to put in a fix and deploy a new version. Thanks for any advise you can give.

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  • Not catching all mouse events with wxWidgets

    - by Stef
    Hi I am am trying to catch mouse movements for a MouseOver function in an app created with Code::Blocks using the wxSmith plugin. I have stumbled upon a puzzling problem. EVT_MOUSEWHEEL calling the function in the EventTable works well, but all other macros have no result at all. And the mousewheel is not really want I want (I just used it to test...) Here is a the basic problem code (mostly generated by the fantastic wxSmith plugin) MouseMain.h #include <wx/frame.h> #include <wx/statusbr.h> //*) class MouseFrame: public wxFrame { public: MouseFrame(wxWindow* parent,wxWindowID id = -1); virtual ~MouseFrame(); private: //(*Handlers(MouseFrame) void OnQuit(wxCommandEvent& event); void OnAbout(wxCommandEvent& event); void OnButton1Click(wxCommandEvent& event); void MouseOver(wxMouseEvent& event); //*) //(*Identifiers(MouseFrame) static const long ID_BUTTON1; static const long ID_STATICBITMAP1; static const long ID_PANEL1; static const long idMenuQuit; static const long idMenuAbout; static const long ID_STATUSBAR1; //*) //(*Declarations(MouseFrame) wxButton* Button1; wxStaticBitmap* StaticBitmap1; wxPanel* Panel1; wxStatusBar* StatusBar1; //*) DECLARE_EVENT_TABLE() }; #endif // MOUSEMAIN_H ...and MouseMain.cpp #include "wx_pch.h" #include "MouseMain.h" #include <wx/msgdlg.h> //(*InternalHeaders(MouseFrame) #include <wx/bitmap.h> #include <wx/intl.h> #include <wx/image.h> #include <wx/string.h> //*) //helper functions enum wxbuildinfoformat { short_f, long_f }; wxString wxbuildinfo(wxbuildinfoformat format) { wxString wxbuild(wxVERSION_STRING); if (format == long_f ) { #if defined(__WXMSW__) wxbuild << _T("-Windows"); #elif defined(__UNIX__) wxbuild << _T("-Linux"); #endif #if wxUSE_UNICODE wxbuild << _T("-Unicode build"); #else wxbuild << _T("-ANSI build"); #endif // wxUSE_UNICODE } return wxbuild; } //(*IdInit(MouseFrame) const long MouseFrame::ID_BUTTON1 = wxNewId(); const long MouseFrame::ID_STATICBITMAP1 = wxNewId(); const long MouseFrame::ID_PANEL1 = wxNewId(); const long MouseFrame::idMenuQuit = wxNewId(); const long MouseFrame::idMenuAbout = wxNewId(); const long MouseFrame::ID_STATUSBAR1 = wxNewId(); //*) BEGIN_EVENT_TABLE(MouseFrame,wxFrame) EVT_RIGHT_DCLICK(MouseFrame::MouseOver) EVT_MOUSEWHEEL(MouseFrame::MouseOver) EVT_MOTION(MouseFrame::MouseOver) EVT_RIGHT_DOWN(MouseFrame::MouseOver) //(*EventTable(MouseFrame) //*) END_EVENT_TABLE() MouseFrame::MouseFrame(wxWindow* parent,wxWindowID id) { //(*Initialize(MouseFrame) wxMenuItem* MenuItem2; wxMenuItem* MenuItem1; wxMenu* Menu1; wxMenuBar* MenuBar1; wxFlexGridSizer* FlexGridSizer1; wxMenu* Menu2; Create(parent, id, wxEmptyString, wxDefaultPosition, wxDefaultSize, wxDEFAULT_FRAME_STYLE, _T("id")); Panel1 = new wxPanel(this, ID_PANEL1, wxPoint(144,392), wxDefaultSize, wxTAB_TRAVERSAL, _T("ID_PANEL1")); FlexGridSizer1 = new wxFlexGridSizer(0, 3, 0, 0); Button1 = new wxButton(Panel1, ID_BUTTON1, _("TheButton"), wxDefaultPosition, wxDefaultSize, 0, wxDefaultValidator, _T("ID_BUTTON1")); FlexGridSizer1->Add(Button1, 1, wxALL|wxALIGN_CENTER_HORIZONTAL|wxALIGN_CENTER_VERTICAL, 5); StaticBitmap1 = new wxStaticBitmap(Panel1, ID_STATICBITMAP1, wxNullBitmap, wxDefaultPosition, wxSize(159,189), wxSUNKEN_BORDER, _T("ID_STATICBITMAP1")); FlexGridSizer1->Add(StaticBitmap1, 1, wxALL|wxALIGN_CENTER_HORIZONTAL|wxALIGN_CENTER_VERTICAL, 5); Panel1->SetSizer(FlexGridSizer1); FlexGridSizer1->Fit(Panel1); FlexGridSizer1->SetSizeHints(Panel1); MenuBar1 = new wxMenuBar(); Menu1 = new wxMenu(); MenuItem1 = new wxMenuItem(Menu1, idMenuQuit, _("Quit\tAlt-F4"), _("Quit the application"), wxITEM_NORMAL); Menu1->Append(MenuItem1); MenuBar1->Append(Menu1, _("&File")); Menu2 = new wxMenu(); MenuItem2 = new wxMenuItem(Menu2, idMenuAbout, _("About\tF1"), _("Show info about this application"), wxITEM_NORMAL); Menu2->Append(MenuItem2); MenuBar1->Append(Menu2, _("Help")); SetMenuBar(MenuBar1); StatusBar1 = new wxStatusBar(this, ID_STATUSBAR1, 0, _T("ID_STATUSBAR1")); int __wxStatusBarWidths_1[1] = { -1 }; int __wxStatusBarStyles_1[1] = { wxSB_NORMAL }; StatusBar1->SetFieldsCount(1,__wxStatusBarWidths_1); StatusBar1->SetStatusStyles(1,__wxStatusBarStyles_1); SetStatusBar(StatusBar1); Connect(ID_BUTTON1,wxEVT_COMMAND_BUTTON_CLICKED,(wxObjectEventFunction)&MouseFrame::OnButton1Click); Connect(idMenuQuit,wxEVT_COMMAND_MENU_SELECTED,(wxObjectEventFunction)&MouseFrame::OnQuit); Connect(idMenuAbout,wxEVT_COMMAND_MENU_SELECTED,(wxObjectEventFunction)&MouseFrame::OnAbout); //*) } MouseFrame::~MouseFrame() { //(*Destroy(MouseFrame) //*) } void MouseFrame::OnQuit(wxCommandEvent& event) { Close(); } void MouseFrame::OnAbout(wxCommandEvent& event) { wxString msg = wxbuildinfo(long_f); wxMessageBox(msg, _("Welcome to...")); } void MouseFrame::OnButton1Click(wxCommandEvent& event) { } void MouseFrame::MouseOver(wxMouseEvent& event){ wxMessageBox(_("MouseOver event!")); } So my big question: Why are EVT_MOTION, EVT_RIGHT_DOWN or EVT_RIGHT_DCLICK not calling MouseFrame::MouseOver(wxMouseEvent& event) in the way EVT_MOUSEWHEEL does?

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  • Mixed-mode C++/CLI crashing: heap corruption in atexit (static destructor registration)

    - by thaimin
    I am working on deploying a program and the codebase is a mixture of C++/CLI and C#. The C++/CLI comes in all flavors: native, mixed (/clr), and safe (/clr:safe). In my development environment I create a DLL of all the C++/CLI code and reference that from the C# code (EXE). This method works flawlessly. For my releases that I want to release a single executable (simply stating that "why not just have a DLL and EXE separate?" is not acceptable). So far I have succeeded in compiling the EXE with all the different sources. However, when I run it I get the "XXXX has stopped working" dialog with options to Check online, Close and Debug. The problem details are as follows: Problem Event Name: APPCRASH Fault Module Name: StackHash_8d25 Fault Module Version: 6.1.7600.16559 Fault Module Timestamp: 4ba9b29c Exception Code: c0000374 Exception Offset: 000cdc9b OS Version: 6.1.7600.2.0.0.256.48 Locale ID: 1033 Additional Information 1: 8d25 Additional Information 2: 8d25552d834e8c143c43cf1d7f83abb8 Additional Information 3: 7450 Additional Information 4: 74509ce510cd821216ce477edd86119c If I debug and send it to Visual Studio, it reports: Unhandled exception at 0x77d2dc9b in XXX.exe: A heap has been corrupted Choosing break results in it stopping at ntdll.dll!77d2dc9b() with no additional information. If I tell Visual Studio to continue, the program starts up fine and seems to work without incident, probably since a debugger is now attached. What do you make of this? How do I avoid this heap corruption? The program seems to work fine except for this. My abridged compilation script is as follows (I have omitted my error checking for brevity): @set TARGET=x86 @set TARGETX=x86 @set OUT=%TARGETX% @call "%VS90COMNTOOLS%\..\..\VC\vcvarsall.bat" %TARGET% @set WIMGAPI=C:\Program Files\Windows AIK\SDKs\WIMGAPI\%TARGET% set CL=/Zi /nologo /W4 /O2 /GS /EHa /MD /MP /D NDEBUG /D _UNICODE /D UNICODE /D INTEGRATED /Fd%OUT%\ /Fo%OUT%\ set INCLUDE=%WIMGAPI%;%INCLUDE% set LINK=/nologo /LTCG /CLRIMAGETYPE:IJW /MANIFEST:NO /MACHINE:%TARGETX% /SUBSYSTEM:WINDOWS,6.0 /OPT:REF /OPT:ICF /DEFAULTLIB:msvcmrt.lib set LIB=%WIMGAPI%;%LIB% set CSC=/nologo /w:4 /d:INTEGRATED /o+ /target:module :: Compiling resources omitted @set CL_NATIVE=/c /FI"stdafx-native.h" @set CL_MIXED=/c /clr /LN /FI"stdafx-mixed.h" @set CL_PURE=/c /clr:safe /LN /GL /FI"stdafx-pure.h" @set NATIVE=... @set MIXED=... @set PURE=... cl %CL_NATIVE% %NATIVE% cl %CL_MIXED% %MIXED% cl %CL_PURE% %PURE% link /LTCG /NOASSEMBLY /DLL /OUT:%OUT%\core.netmodule %OUT%\*.obj csc %CSC% /addmodule:%OUT%\core.netmodule /out:%OUT%\GUI.netmodule /recurse:*.cs link /FIXED /ENTRY:GUI.Program.Main /OUT:%OUT%\XXX.exe ^ /ASSEMBLYRESOURCE:%OUT%\core.resources,XXX.resources,PRIVATE /ASSEMBLYRESOURCE:%OUT%\GUI.resources,GUI.resources,PRIVATE ^ /ASSEMBLYMODULE:%OUT%\core.netmodule %OUT%\gui.res %OUT%\*.obj %OUT%\GUI.netmodule Update 1 Upon compiling this with debug symbols and trying again, I do in fact get more information. The call stack is: msvcr90d.dll!_msize_dbg(void * pUserData, int nBlockUse) Line 1511 + 0x30 bytes msvcr90d.dll!_dllonexit_nolock(int (void)* func, void (void)* * * pbegin, void (void)* * * pend) Line 295 + 0xd bytes msvcr90d.dll!__dllonexit(int (void)* func, void (void)* * * pbegin, void (void)* * * pend) Line 273 + 0x11 bytes XXX.exe!_onexit(int (void)* func) Line 110 + 0x1b bytes XXX.exe!atexit(void (void)* func) Line 127 + 0x9 bytes XXX.exe!`dynamic initializer for 'Bytes::Null''() Line 7 + 0xa bytes mscorwks.dll!6cbd1b5c() [Frames below may be incorrect and/or missing, no symbols loaded for mscorwks.dll] ... The line of my code that 'causes' this (dynamic initializer for Bytes::Null) is: Bytes Bytes::Null; In the header that is declared as: class Bytes { public: static Bytes Null; } I also tried doing a global extern in the header like so: extern Bytes Null; // header Bytes Null; // cpp file Which failed in the same way. It seems that the CRT atexit function is responsible, being inadvertently required due to the static initializer. Fix As Ben Voigt pointed out the use of any CRT functions (including native static initializers) requires proper initialization of the CRT (which happens in mainCRTStartup, WinMainCRTStartup, or _DllMainCRTStartup). I have added a mixed C++/CLI file that has a C++ main or WinMain: using namespace System; [STAThread] // required if using an STA COM objects (such as drag-n-drop or file dialogs) int main() { // or "int __stdcall WinMain(void*, void*, wchar_t**, int)" for GUI applications array<String^> ^args_orig = Environment::GetCommandLineArgs(); int l = args_orig->Length - 1; // required to remove first argument (program name) array<String^> ^args = gcnew array<String^>(l); if (l > 0) Array::Copy(args_orig, 1, args, 0, l); return XXX::CUI::Program::Main(args); // return XXX::GUI::Program::Main(args); } After doing this, the program now gets a little further, but still has issues (which will be addressed elsewhere): When the program is solely in C# it works fine, along with whenever it is just calling C++/CLI methods, getting C++/CLI properties, and creating managed C++/CLI objects Events added by C# into the C++/CLI code never fire (even though they should) One other weird error is that an exception happens is a InvalidCastException saying can't cast from X to X (where X is the same as X...) However since the heap corruption is fixed (by getting the CRT initialized) the question is done.

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  • Multi-step Workflows: make Workflow A depend on results of Workflow B and/or Workflow C

    - by Joey
    I have been tasked with creating a Software Installation Approval section for our Intranet. When a person requests that a particular piece of software be installed on their workstation, we need to get IT approval and then business approval. Once those are obtained, it is to be installed. I am using Sharepoint Designer to do this. I have List A, where the user enters the information on the requested software. Workflow A then creates a Task in List B, which is then assigned to the IT approver. Workflow B works on List B on item creation, setting the due dates, titles, and other fields, and then pauses until the due date. The IT approver works with the business side and completes the task. Once List B task is complete, the item in List A should be marked as complete -- I have everything up to this point working fine. I want to make this more robust in 2 ways. As the only real option is to mark List B task as "completed", which essentially means "Approved", we have no way of really denying a request. What I want to add is the option to approve or deny a request through the task on List B -- if it is approved, I want the item in List A to continue to show "In Progress" with a custom status of "Approved", and I want to create a new task for software installation; once the installation task is marked as completed, then I want List A to show "Completed" with a status of "Installed". If it is denied, I want the item in List A to show as "Completed", with a status of "Denied". The problem is, I'm not even sure where to start making these modifications. Creating and modifying the custom status fields isn't that big of an issue -- I have messed around with this and I'm fairly confident I can do this easily. My main concern is that I know I will need a Workflow C, but I don't know where or how to trigger this to get the results I need. I've managed to get Workflows A and B working fine, but anything beyond this is really pushing the limit of my knowledge. It's probably obvious that I am rather new to Sharepoint workflows. I was very much thrust into this position and I am still feeling my way around. Thanks in advance for any help!

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  • Find Control in Grid

    - by Eric
    I have a RadGrid with radio buttons on the inside of a FormTemplate. I want hide the panels below or show the panels below on checkchanged of the radio button. However, my issue is that i don't know how to access the panels oncheckchanged. Any help would be appreciate. Thanks in advance. protected void RadioButtonCompany_CheckChanged(object sender, EventArgs e) { RadioButton RadioButtonCompany = (RadioButton)sender; Panel pnlPerson = (Panel)RadGridInjuries.Items[1].FindControl("pnlPerson"); Panel pnlcomp = (Panel)RadGridInjuries.MasterTableView.FindControl("pnlComp"); if (RadioButtonCompany.Checked) { pnlPerson.Visible = false; pnlcomp.Visible = true; } else { pnlPerson.Visible = true; pnlcomp.Visible = false; } } <telerik:RadGrid ID="RadGridInjuries" DataSourceID="DSource"> <GroupingSettings CaseSensitive="false" /> <SelectedItemStyle CssClass="Cursor" /> <ItemStyle CssClass="Cursor" /> <MasterTableView TableLayout="Auto" CssClass="Cursor" CanRetrieveAllData="true" CommandItemDisplay="Top" ShowHeadersWhenNoRecords="false" GridLines="Both" runat="server"> <ItemStyle CssClass="Cursor" /> <EditFormSettings EditFormType="Template" > <FormTemplate> <table id="Table2" width="100%" border="0" rules="none" style="border-collapse: collapse;background:#F0F0F0"> <tr> <td style="font-size: medium;color:Blue"> <b>Provider Details Information</b></td> </tr> <tr><td><br /></td></tr> <tr> <td> <asp:RadioButton ID="RadioButtonCompany" OnCheckedChanged="RadioButtonCompany_CheckChanged" runat="server" Text="Company" GroupName="Type" AutoPostBack="true" /> <asp:RadioButton ID="RadioButtonPerson" runat="server" Text="Person" GroupName="Type" AutoPostBack="true" /> </td> </tr> <tr><td><br /></td></tr> <tr> <td align="center"> <asp:Panel ID="pnlPerson" runat="server" Visible="false"> //stuff in here <asp:/Panel> <asp:Panel ID="pnlCompany" runat="server" Visible="false"> //stuff in here <asp:/Panel> </FormTemplate> </EditFormSettings> </MasterTableView> <ClientSettings EnableRowHoverStyle="true" EnablePostBackOnRowClick="false"> <Selecting AllowRowSelect="True" EnableDragToSelectRows="true" /> <ClientEvents /> </ClientSettings> </telerik:RadGrid>

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  • How to read verbose VC++ linker output

    - by Assaf Lavie
    Trying to debug some linker errors, I turned on /VERBOSE and I'm trying to make sense of the output. It occurs to me that I really don't know how to read it. For example: 1>Compiling version info 1>Linking... 1>Starting pass 1 1>Processed /DEFAULTLIB:mfc80.lib 1>Processed /DEFAULTLIB:mfcs80.lib 1>Processed /DEFAULTLIB:msvcrt.lib 1>Processed /DEFAULTLIB:kernel32.lib 1>Processed /DEFAULTLIB:user32.lib .... 1>Processed /DEFAULTLIB:libgslcblasMD.lib 1>Searching libraries 1> Searching V:\Src\Solutions\\..\..\\Common\Win32\Lib\PlxApi.lib: 1> Searching ..\..\..\..\out\win32\release\lib\camerageometry.lib: 1> Searching ..\..\..\..\out\win32\release\lib\geometry.lib: 1> Found "public: __thiscall VisionMap::Geometry::Box2d::operator class VisionMap::Geometry::Box2DInt(void)const " (??BBox2d@Geometry@VisionMap@@QBE?AVBox2DInt@12@XZ) 1> Referenced in FocusDlg.obj 1> Loaded geometry.lib(Box2d.obj) 1>Processed /DEFAULTLIB:CGAL-vc80-mt.lib 1>Processed /DEFAULTLIB:boost_thread-vc80-mt-1_33_1.lib What's going on here? I think I understand this bit: 1>Processed /DEFAULTLIB:libgslcblasMD.lib 1>Searching libraries 1> Searching V:\Src\Solutions\\..\..\\Common\Win32\Lib\PlxApi.lib: 1> Searching ..\..\..\..\out\win32\release\lib\camerageometry.lib: 1> Searching ..\..\..\..\out\win32\release\lib\geometry.lib: 1> Found "public: __thiscall VisionMap::Geometry::Box2d::operator class VisionMap::Geometry::Box2DInt(void)const " (??BBox2d@Geometry@VisionMap@@QBE?AVBox2DInt@12@XZ) 1> Referenced in FocusDlg.obj 1> Loaded geometry.lib(Box2d.obj) It's trying to find the implementation of the above operator, which is used somewhere in FocusDlg.cpp, and it finds it in geometry.lib. But what does 1>Processed /DEFAULTLIB:libgslcblasMD.lib mean? What determines the order of symbol resolution? Why is it loading this particular symbol while processing libgslcblasMD.lib which is a 3rd party library? Or am I reading it wrong? It seems that the linker is going through the symbols referenced in the project's various object files, but I have no idea in what order. It then searches the static libraries the project uses - by project reference, explicit import and automatic default library imports; but it does so in an order that, again, seems arbitrary to me. When it finds a symbol, for example in geometry.lib, it then continues to find a bunch of other symbols from the same lib: 1> Searching V:\Src\Solutions\\..\..\\Common\Win32\Lib\PlxApi.lib: 1> Searching ..\..\..\..\out\win32\release\lib\camerageometry.lib: 1> Searching ..\..\..\..\out\win32\release\lib\geometry.lib: 1> Found "public: __thiscall VisionMap::Geometry::Box2d::operator class VisionMap::Geometry::Box2DInt(void)const " (??BBox2d@Geometry@VisionMap@@QBE?AVBox2DInt@12@XZ) 1> Referenced in FocusDlg.obj 1> Loaded geometry.lib(Box2d.obj) 1>Processed /DEFAULTLIB:CGAL-vc80-mt.lib 1>Processed /DEFAULTLIB:boost_thread-vc80-mt-1_33_1.lib 1> Found "public: __thiscall VisionMap::Geometry::Box2DInt::Box2DInt(int,int,int,int)" (??0Box2DInt@Geometry@VisionMap@@QAE@HHHH@Z) 1> Referenced in FocusDlg.obj 1> Referenced in ImageView.obj 1> Referenced in geometry.lib(Box2d.obj) 1> Loaded geometry.lib(Box2DInt.obj) 1> Found "public: virtual __thiscall VisionMap::Geometry::Point3d::~Point3d(void)" (??1Point3d@Geometry@VisionMap@@UAE@XZ) 1> Referenced in GPSFrm.obj 1> Referenced in MainFrm.obj 1> Loaded geometry.lib(Point3d.obj) 1> Found "void __cdecl VisionMap::Geometry::serialize<class boost::archive::binary_oarchive>(class boost::archive::binary_oarchive &,class VisionMap::Geometry::Point3d &,unsigned int)" (??$serialize@Vbinary_oarchive@archive@boost@@@Geometry@VisionMap@@YAXAAVbinary_oarchive@archive@boost@@AAVPoint3d@01@I@Z) 1> Referenced in GPSFrm.obj 1> Referenced in MainFrm.obj 1> Loaded geometry.lib(GeometrySerializationImpl.obj) But then, for some reason, it goes on to find symbols that are defined in other libs, and returns to geometry later on (a bunch of times). So clearly it's not doing "look in geometry and load every symbol that's references in the project, and then continue to other libraries". But it's not clear to me what is the order of symbol lookup. And what's the deal with all those libraries being processed at the beginning of the linker's work, but not finding any symbols to load from them? Does this project really not use anything from msvcrt.lib, kernel32.lib? Seems unlikely. So basically I'm looking to decipher the underlying order in the linker's operation.

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  • Cannot call SAPI from dll

    - by Quandary
    Question: The below code works fine as long as it is in an executable. It uses the msft (text-to-)speech API (SAPI). But as soon as I put it in a dll and load it with loadlibrary from an executable, it doesn't work. I've also tried to change CoInitialize(NULL); to CoInitializeEx(NULL,COINIT_MULTITHREADED); and I tried with all possible flags ( COINIT_APARTMENTTHREADED, COINIT_MULTITHREADED, COINIT_DISABLE_OLE1DDE, COINIT_SPEED_OVER_MEMORY) But it's always stuck at hr = CoCreateInstance(__uuidof(SpVoice), NULL, CLSCTX_INPROC_SERVER, IID_ISpVoice, (void **) &pVoice); I also tried those flags here: CLSCTX_INPROC_SERVER,CLSCTX_SERVER, CLSCTX_ALL, but nothing seems to help... There are no errors, it doesn't crash, it just sleeps forever at CoCreateInstance... This is the code as single exe (working) #include <windows.h> #include <sapi.h> #include <iostream> #include <cstdlib> int main(int argc, char* argv[]) { ISpVoice * pVoice = NULL; //CoInitializeEx(NULL,COINIT_MULTITHREADED); HRESULT hr = CoInitialize(NULL); if( FAILED(hr) ) { MessageBox(NULL, TEXT("Failed To Initialize"), TEXT("Error"),0); printf("Failed!\n"); char buffer[2000] ; sprintf(buffer, "An error occured: 0x%08X.\n", hr); FILE * pFile = fopen ( "c:\\temp\\CoInitialize_exe.txt" , "w" ); fwrite (buffer , 1 , sizeof(buffer) , pFile ); fclose (pFile); } else { //CoGetClassObject(CLSID_SpVoice, CLSCTX_INPROC_SERVER, NULL, IID_IClassFactory, (void**) &pClsF); //hr = CoGetClassObject(CLSID_SpVoice, CLSCTX_INPROC_SERVER, NULL, IID_IClassFactory, (void**) &pClsF); hr = CoCreateInstance(__uuidof(SpVoice), NULL, CLSCTX_INPROC_SERVER, IID_ISpVoice, (void **) &pVoice); //HRESULT hr = CoCreateInstance(CLSID_SpVoice, NULL, CLSCTX_ALL, IID_ISpVoice, (void **) &pVoice); if( SUCCEEDED( hr ) ) { hr = pVoice->Speak(L"Test Test", 0, NULL); hr = pVoice->Speak(L"This sounds normal <pitch middle = '-10'/> but the pitch drops half way through", SPF_IS_XML, NULL ); pVoice->Release(); pVoice = NULL; } else { MessageBox(NULL, TEXT("Failed To Create a COM instance..."), TEXT("Error"),0); char buffer[2000] ; sprintf(buffer, "An error occured: 0x%08X.\n", hr); FILE * pFile = fopen ( "c:\\temp\\CoCreateInstance_exe.txt" , "w" ); fwrite (buffer , 1 , sizeof(buffer) , pFile ); fclose (pFile); } } CoUninitialize(); return EXIT_SUCCESS; } This is the exe loading the dll (stays forever at printf("trying to create instance.\n"); ) #include <windows.h> #include <sapi.h> #include <iostream> #include <cstdlib> int main(int argc, char* argv[]) { // C:\Windows\System32\Speech\Common\sapi.dll //LoadLibraryA("sapi.dll"); LoadLibraryA("Sapidll2.dll"); return EXIT_SUCCESS; // Frankly, that would be nice... } And this is Sapidll2.dll // dllmain.cpp : Defines the entry point for the DLL application. #include "stdafx.h" #include <iostream> #include <cstdlib> #include <string> #include <windows.h> #include <sapi.h> int init_engine() { ISpVoice * pVoice = NULL; //HRESULT hr = CoInitializeEx(NULL, COINIT_MULTITHREADED); HRESULT hr = CoInitialize(NULL); if(FAILED(hr) ) { MessageBox(NULL, TEXT("Failed To Initialize"), TEXT("Error"), 0); char buffer[2000] ; sprintf(buffer, "An error occured: 0x%08X.\n", hr); FILE * pFile = fopen ( "c:\\temp\\CoInitialize_dll.txt" , "w" ); fwrite (buffer , 1 , strlen(buffer) , pFile ); fclose (pFile); } else { printf("trying to create instance.\n"); //HRESULT hr = CoCreateInstance(CLSID_SpVoice, NULL, CLSCTX_ALL, IID_ISpVoice, (void **) &pVoice); //hr = CoCreateInstance(CLSID_SpVoice, NULL, CLSCTX_ALL, IID_ISpVoice, (void **) &pVoice); //HRESULT hr = CoCreateInstance(__uuidof(ISpVoice), NULL, CLSCTX_INPROC_SERVER, IID_ISpVoice, (void **) &pVoice); HRESULT hr = CoCreateInstance(__uuidof(SpVoice), NULL, CLSCTX_ALL, IID_ISpVoice, (void **) &pVoice); if( SUCCEEDED( hr ) ) { printf("Succeeded\n"); //hr = pVoice->Speak(L"The text to speech engine has been successfully initialized.", 0, NULL); } else { printf("failed\n"); MessageBox(NULL, TEXT("Failed To Create COM instance"), TEXT("Error"), 0); char buffer[2000] ; sprintf(buffer, "An error occured: 0x%08X.\n", hr); FILE * pFile = fopen ( "c:\\temp\\CoCreateInstance_dll.txt" , "w" ); fwrite (buffer , 1 , strlen(buffer) , pFile ); fclose (pFile); } } if(pVoice != NULL) { pVoice->Release(); pVoice = NULL; } CoUninitialize(); return true ; } BOOL APIENTRY DllMain( HMODULE hModule, DWORD ul_reason_for_call, LPVOID lpReserved) { switch (ul_reason_for_call) { case DLL_PROCESS_ATTACH: init_engine(); break; case DLL_THREAD_ATTACH: case DLL_THREAD_DETACH: case DLL_PROCESS_DETACH: break; } return TRUE; }

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  • Can you help me get my head around openssl public key encryption with rsa.h in c++?

    - by Ben
    Hi there, I am trying to get my head around public key encryption using the openssl implementation of rsa in C++. Can you help? So far these are my thoughts (please do correct if necessary) Alice is connected to Bob over a network Alice and Bob want secure communications Alice generates a public / private key pair and sends public key to Bob Bob receives public key and encrypts a randomly generated symmetric cypher key (e.g. blowfish) with the public key and sends the result to Alice Alice decrypts the ciphertext with the originally generated private key and obtains the symmetric blowfish key Alice and Bob now both have knowledge of symmetric blowfish key and can establish a secure communication channel Now, I have looked at the openssl/rsa.h rsa implementation (since I already have practical experience with openssl/blowfish.h), and I see these two functions: int RSA_public_encrypt(int flen, unsigned char *from, unsigned char *to, RSA *rsa, int padding); int RSA_private_decrypt(int flen, unsigned char *from, unsigned char *to, RSA *rsa, int padding); If Alice is to generate *rsa, how does this yield the rsa key pair? Is there something like rsa_public and rsa_private which are derived from rsa? Does *rsa contain both public and private key and the above function automatically strips out the necessary key depending on whether it requires the public or private part? Should two unique *rsa pointers be generated so that actually, we have the following: int RSA_public_encrypt(int flen, unsigned char *from, unsigned char *to, RSA *rsa_public, int padding); int RSA_private_decrypt(int flen, unsigned char *from, unsigned char *to, RSA *rsa_private, int padding); Secondly, in what format should the *rsa public key be sent to Bob? Must it be reinterpreted in to a character array and then sent the standard way? I've heard something about certificates -- are they anything to do with it? Sorry for all the questions, Best Wishes, Ben. EDIT: Coe I am currently employing: /* * theEncryptor.cpp * * * Created by ben on 14/01/2010. * Copyright 2010 __MyCompanyName__. All rights reserved. * */ #include "theEncryptor.h" #include <iostream> #include <sys/socket.h> #include <sstream> theEncryptor::theEncryptor() { } void theEncryptor::blowfish(unsigned char *data, int data_len, unsigned char* key, int enc) { // hash the key first! unsigned char obuf[20]; bzero(obuf,20); SHA1((const unsigned char*)key, 64, obuf); BF_KEY bfkey; int keySize = 16;//strlen((char*)key); BF_set_key(&bfkey, keySize, obuf); unsigned char ivec[16]; memset(ivec, 0, 16); unsigned char* out=(unsigned char*) malloc(data_len); bzero(out,data_len); int num = 0; BF_cfb64_encrypt(data, out, data_len, &bfkey, ivec, &num, enc); //for(int i = 0;i<data_len;i++)data[i]=out[i]; memcpy(data, out, data_len); free(out); } void theEncryptor::generateRSAKeyPair(int bits) { rsa = RSA_generate_key(bits, 65537, NULL, NULL); } int theEncryptor::publicEncrypt(unsigned char* data, unsigned char* dataEncrypted,int dataLen) { return RSA_public_encrypt(dataLen, data, dataEncrypted, rsa, RSA_PKCS1_OAEP_PADDING); } int theEncryptor::privateDecrypt(unsigned char* dataEncrypted, unsigned char* dataDecrypted) { return RSA_private_decrypt(RSA_size(rsa), dataEncrypted, dataDecrypted, rsa, RSA_PKCS1_OAEP_PADDING); } void theEncryptor::receivePublicKeyAndSetRSA(int sock, int bits) { int max_hex_size = (bits / 4) + 1; char keybufA[max_hex_size]; bzero(keybufA,max_hex_size); char keybufB[max_hex_size]; bzero(keybufB,max_hex_size); int n = recv(sock,keybufA,max_hex_size,0); n = send(sock,"OK",2,0); n = recv(sock,keybufB,max_hex_size,0); n = send(sock,"OK",2,0); rsa = RSA_new(); BN_hex2bn(&rsa->n, keybufA); BN_hex2bn(&rsa->e, keybufB); } void theEncryptor::transmitPublicKey(int sock, int bits) { const int max_hex_size = (bits / 4) + 1; long size = max_hex_size; char keyBufferA[size]; char keyBufferB[size]; bzero(keyBufferA,size); bzero(keyBufferB,size); sprintf(keyBufferA,"%s\r\n",BN_bn2hex(rsa->n)); sprintf(keyBufferB,"%s\r\n",BN_bn2hex(rsa->e)); int n = send(sock,keyBufferA,size,0); char recBuf[2]; n = recv(sock,recBuf,2,0); n = send(sock,keyBufferB,size,0); n = recv(sock,recBuf,2,0); } void theEncryptor::generateRandomBlowfishKey(unsigned char* key, int bytes) { /* srand( (unsigned)time( NULL ) ); std::ostringstream stm; for(int i = 0;i<bytes;i++){ int randomValue = 65 + rand()% 26; stm << (char)((int)randomValue); } std::string str(stm.str()); const char* strs = str.c_str(); for(int i = 0;bytes;i++)key[i]=strs[i]; */ int n = RAND_bytes(key, bytes); if(n==0)std::cout<<"Warning key was generated with bad entropy. You should not consider communication to be secure"<<std::endl; } theEncryptor::~theEncryptor(){}

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  • Semi-complex aggregate select statement confusion

    - by Ian Henry
    Alright, this problem is a little complicated, so bear with me. I have a table full of data. One of the table columns is an EntryDate. There can be multiple entries per day. However, I want to select all rows that are the latest entry on their respective days, and I want to select all the columns of said table. One of the columns is a unique identifier column, but it is not the primary key (I have no idea why it's there; this is a pretty old system). For purposes of demonstration, say the table looks like this: create table ExampleTable ( ID int identity(1,1) not null, PersonID int not null, StoreID int not null, Data1 int not null, Data2 int not null, EntryDate datetime not null ) The primary key is on PersonID and StoreID, which logically defines uniqueness. Now, like I said, I want to select all the rows that are the latest entries on that particular day (for each Person-Store combination). This is pretty easy: --Figure 1 select PersonID, StoreID, max(EntryDate) from ExampleTable group by PersonID, StoreID, dbo.dayof(EntryDate) Where dbo.dayof() is a simple function that strips the time component from a datetime. However, doing this loses the rest of the columns! I can't simply include the other columns, because then I'd have to group by them, which would produce the wrong results (especially since ID is unique). I have found a dirty hack that will do what I want, but there must be a better way -- here's my current solution: select cast(null as int) as ID, PersonID, StoreID, cast(null as int) as Data1, cast(null as int) as Data2, max(EntryDate) as EntryDate into #StagingTable from ExampleTable group by PersonID, StoreID, dbo.dayof(EntryDate) update Target set ID = Source.ID, Data1 = Source.Data1, Data2 = Source.Data2, from #StagingTable as Target inner join ExampleTable as Source on Source.PersonID = Target.PersonID and Source.StoreID = Target.StoreID and Source.EntryDate = Target.EntryDate This gets me the correct data in #StagingTable but, well, look at it! Creating a table with null values, then doing an update to get the values back -- surely there's a better way to do this? A single statement that will get me all the values the first time? It is my belief that the correct join on that original select (Figure 1) would do the trick, like a self-join or something... but how do you do that with the group by clause? I cannot find the right syntax to make the query execute. I am pretty new with SQL, so it's likely that I'm missing something obvious. Any suggestions? (Working in T-SQL, if it makes any difference)

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  • Java language features which have no equivalent in C#

    - by jthg
    Having mostly worked with C#, I tend to think in terms of C# features which aren't available in Java. After working extensively with Java over the last year, I've started to discover Java features that I wish were in C#. Below is a list of the ones that I'm aware of. Can anyone think of other Java language features which a person with a C# background may not realize exists? The articles http://www.25hoursaday.com/CsharpVsJava.html and http://en.wikipedia.org/wiki/Comparison_of_Java_and_C_Sharp give a very extensive list of differences between Java and C#, but I wonder whether I missed anything in the (very) long articles. I can also think of one feature (covariant return type) which I didn't see mentioned in either article. Please limit answers to language or core library features which can't be effectively implemented by your own custom code or third party libraries. Covariant return type - a method can be overridden by a method which returns a more specific type. Useful when implementing an interface or extending a class and you want a method to override a base method, but return a type more specific to your class. Enums are classes - an enum is a full class in java, rather than a wrapper around a primitive like in .Net. Java allows you to define fields and methods on an enum. Anonymous inner classes - define an anonymous class which implements a method. Although most of the use cases for this in Java are covered by delegates in .Net, there are some cases in which you really need to pass multiple callbacks as a group. It would be nice to have the choice of using an anonymous inner class. Checked exceptions - I can see how this is useful in the context of common designs used with Java applications, but my experience with .Net has put me in a habit of using exceptions only for unrecoverable conditions. I.E. exceptions indicate a bug in the application and are only caught for the purpose of logging. I haven't quite come around to the idea of using exceptions for normal program flow. strictfp - Ensures strict floating point arithmetic. I'm not sure what kind of applications would find this useful. fields in interfaces - It's possible to declare fields in interfaces. I've never used this. static imports - Allows one to use the static methods of a class without qualifying it with the class name. I just realized today that this feature exists. It sounds like a nice convenience.

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  • Connecting to MSSQL 2008 from Java

    - by Xinus
    I am trying to connect to MSSQL 2008 server from Java here is a program import java.sql.*; public class connectURL { public static void main(String[] args) { // Create a variable for the connection string. String connectionUrl = "jdbc:sqlserver://localhost/SQLEXPRESS/Databases/HelloWorld:1433;";// + //"databaseName=HelloWorld;integratedSecurity=true;"; // Declare the JDBC objects. Connection con = null; Statement stmt = null; ResultSet rs = null; try { // Establish the connection. Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver"); con = DriverManager.getConnection(connectionUrl); // Create and execute an SQL statement that returns some data. String SQL = "SELECT TOP 10 * FROM Person.Contact"; stmt = con.createStatement(); rs = stmt.executeQuery(SQL); // Iterate through the data in the result set and display it. while (rs.next()) { System.out.println(rs.getString(4) + " " + rs.getString(6)); } } // Handle any errors that may have occurred. catch (Exception e) { e.printStackTrace(); } finally { if (rs != null) try { rs.close(); } catch(Exception e) {} if (stmt != null) try { stmt.close(); } catch(Exception e) {} if (con != null) try { con.close(); } catch(Exception e) {} } } } But it shows error as com.microsoft.sqlserver.jdbc.SQLServerException: The TCP/IP connection to the host localhost/SQLEXPRESS/Databases/HelloWorld, port 1433 has failed. Error: "null. Verify the connection properties, check that an instance of SQL Server is running on the host and accepting TCP/IP connections at the port, and that no firewall is blocking TCP connections to the port.". at com.microsoft.sqlserver.jdbc.SQLServerException.makeFromDriverError(SQLServerException.java:170) at com.microsoft.sqlserver.jdbc.SQLServerConnection.connectHelper(SQLServerConnection.java:1049) at com.microsoft.sqlserver.jdbc.SQLServerConnection.login(SQLServerConnection.java:833) at com.microsoft.sqlserver.jdbc.SQLServerConnection.connect(SQLServerConnection.java:716) at com.microsoft.sqlserver.jdbc.SQLServerDriver.connect(SQLServerDriver.java:841) at java.sql.DriverManager.getConnection(Unknown Source) at java.sql.DriverManager.getConnection(Unknown Source) at connectURL.main(connectURL.java:43) I have given followed all the instructions as given in http://teamtutorials.com/database-tutorials/configuring-and-creating-a-database-in-ms-sql-2008 What can be the problem ?

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  • Dropdownlist and Datareader

    - by salvationishere
    After trying many solutions listed on the internet I am very confused now. I have a C#/SQL web application for which I am simply trying to bind an ExecuteReader command to a Dropdownlist so the user can select a value. This is a VS2008 project on an XP OS. How it works is after the user selects a table, I use this selection as an input parameter to a method from my Datamatch.aspx.cs file. Then this Datamatch.aspx.cs file calls a method from my ADONET.cs class file. Finally this method executes a SQL procedure to return the list of columns from that table. (These are all tables in Adventureworks DB). I know that this method returns successfully the list of columns if I execute this SP in SSMS. However, I'm not sure how to tell if it works in VS or not. This should be simple. How can I do this? Here is some of my code. The T-sQL stored proc: CREATE PROCEDURE [dbo].[getColumnNames] @TableName VarChar(50) AS BEGIN SET NOCOUNT ON; SELECT col.name 'COLUMN_NAME' FROM sysobjects obj INNER JOIN syscolumns col ON obj.id = col.id WHERE obj.name = @TableName END It gives me desired output when I execute following from SSMS: exec getColumnNames 'AddressType' And the code from Datamatch.aspx.cs file currently is: // Add DropDownList Control to Placeholder private void CreateDropDownLists() { SqlDataReader dr2 = ADONET_methods.DisplayTableColumns(targettable); int NumControls = targettable.Length; DropDownList ddl = new DropDownList(); } Where ADONET_methods.DisplayTableColumns(targettable) is: public static SqlDataReader DisplayTableColumns(string tt) { SqlDataReader dr = null; string TableName = tt; string connString = "Server=(local);Database=AdventureWorks;Integrated Security = SSPI"; string errorMsg; SqlConnection conn2 = new SqlConnection(connString); SqlCommand cmd = new SqlCommand("getColumnNames"); //conn2.CreateCommand(); try { cmd.CommandType = CommandType.StoredProcedure; cmd.Connection = conn2; SqlParameter parm = new SqlParameter("@TableName", SqlDbType.VarChar); parm.Value = "Person." + TableName.Trim(); parm.Direction = ParameterDirection.Input; cmd.Parameters.Add(parm); conn2.Open(); dr = cmd.ExecuteReader(); } catch (Exception ex) { errorMsg = ex.Message; } return dr; }

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  • Qt - drag and drop with graphics view framework

    - by David Davidson
    I'm trying to make a simple draggable item using the graphics framework. Here's the code for what I did so far: Widget class: class Widget : public QWidget { Q_OBJECT public: Widget(QWidget *parent = 0); ~Widget(); }; Widget::Widget(QWidget *parent) : QWidget(parent) { DragScene *scene = new DragScene(); DragView *view = new DragView(); QHBoxLayout *layout = new QHBoxLayout(); DragItem *item = new DragItem(); view->setAcceptDrops(true); scene->addItem(item); view->setScene(scene); layout->addWidget(view); this->setLayout(layout); } Widget::~Widget() { } DragView class: class DragView : public QGraphicsView { public: DragView(QWidget *parent = 0); }; DragView::DragView(QWidget *parent) : QGraphicsView(parent) { setRenderHints(QPainter::Antialiasing); } DragScene class: class DragScene : public QGraphicsScene { public: DragScene(QObject* parent = 0); protected: void dragEnterEvent(QGraphicsSceneDragDropEvent *event); void dragMoveEvent(QGraphicsSceneDragDropEvent *event); void dragLeaveEvent(QGraphicsSceneDragDropEvent *event); void dropEvent(QGraphicsSceneDragDropEvent *event); }; DragScene::DragScene(QObject* parent) : QGraphicsScene(parent) { } void DragScene::dragEnterEvent(QGraphicsSceneDragDropEvent *event){ } void DragScene::dragMoveEvent(QGraphicsSceneDragDropEvent *event){ } void DragScene::dragLeaveEvent(QGraphicsSceneDragDropEvent *event){ } void DragScene::dropEvent(QGraphicsSceneDragDropEvent *event){ qDebug() << event->pos(); event->acceptProposedAction(); DragItem *item = new DragItem(); this->addItem(item); item->setPos(event->pos()); } DragItem class: class DragItem : public QGraphicsItem { public: DragItem(QGraphicsItem *parent = 0); QRectF boundingRect() const; void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = 0); protected: void mouseDoubleClickEvent(QGraphicsSceneMouseEvent *event); void mouseMoveEvent(QGraphicsSceneMouseEvent *event); void mousePressEvent(QGraphicsSceneMouseEvent *event); void mouseReleaseEvent(QGraphicsSceneMouseEvent *event); }; DragItem::DragItem(QGraphicsItem *parent) : QGraphicsItem(parent) { setFlag(QGraphicsItem::ItemIsMovable); } QRectF DragItem::boundingRect() const{ const QPointF *p0 = new QPointF(-10,-10); const QPointF *p1 = new QPointF(10,10); return QRectF(*p0,*p1); } void DragItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget){ if(painter == 0) painter = new QPainter(); painter->drawEllipse(QPoint(0,0),10,10); } void DragItem::mouseDoubleClickEvent(QGraphicsSceneMouseEvent *event){ } void DragItem::mouseMoveEvent(QGraphicsSceneMouseEvent *event){ } void DragItem::mousePressEvent(QGraphicsSceneMouseEvent *event){ QMimeData* mime = new QMimeData(); QDrag* drag = new QDrag(event->widget()); drag->setMimeData(mime); drag->exec(); } void DragItem::mouseReleaseEvent(QGraphicsSceneMouseEvent *event){ } main.cpp instantiates a Widget and shows it. When I try to drag the circle, the app just creates another circle over the original one, regardless of where I release the drag. qDebug() in DragScene's dropEvent() shows QPointF(0,0) everytime the drag ends. I'm having a hard time trying to understand exactly what I have to do, which classes I should subclass, which methods needs to be overriden, to make this work. The documentation on this isn't very detailed. I'd like to know how to make this work, and if there's some other, more comprehensive resource to learn about the graphics view framework, besides the official documentation (which is excellent btw, but it would be great if there was a more detailed treatise on the subject). EDIT: Following badgerr's advice, I replaced item-pos() in DragScene::dropEvent() with item-scenePos(), now the drop event creates a new circle in the drop site, which is more or less what I wanted. But the original circle is still in place, and while the drag is in progress, the item doesn't follow the mouse cursor. The QGraphicsSceneDragDropEvent documentation says that pos() should return the cursor position in relation to the view that sent the event, which, unless I got it wrong, shouldn't be (0,0) all the time. Weird. I've read in a forum post that you can use QDrag::setPixMap() to show something during the drag, and in examples I've seen pictures being set as pixmaps, but how do I make the pixmap just like the graphics item I'm supposed to be dragging?

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  • Storing a set of criteria in another table

    - by bendataclear
    I have a large table with sales data, useful data below: RowID Date Customer Salesperson Product_Type Manufacturer Quantity Value 1 01-06-2004 James Ian Taps Tap Ltd 200 £850 2 02-06-2004 Apple Fran Hats Hats Inc 30 £350 3 04-06-2004 James Lawrence Pencils ABC Ltd 2000 £980 ... Many rows later... ... 185352 03-09-2012 Apple Ian Washers Tap Ltd 600 £80 I need to calculate a large set of targets from table containing values different types, target table is under my control and so far is like: TargetID Year Month Salesperson Target_Type Quantity 1 2012 7 Ian 1 6000 2 2012 8 James 2 2000 3 2012 9 Ian 2 6500 At present I am working out target types using a view of the first table which has a lot of extra columns: SELECT YEAR(Date) , MONTH(Date) , Salesperson , Quantity , CASE WHEN Manufacturer IN ('Tap Ltd','Hats Inc') AND Product_Type = 'Hats' THEN True ELSE False END AS IsType1 , CASE WHEN Manufacturer = 'Hats Inc' AND Product_Type IN ('Hats','Coats') THEN True ELSE False END AS IsType2 ... ... , CASE WHEN Manufacturer IN ('Tap Ltd','Hats Inc') AND Product_Type = 'Hats' THEN True ELSE False END AS IsType24 , CASE WHEN Manufacturer IN ('Tap Ltd','Hats Inc') AND Product_Type = 'Hats' THEN True ELSE False END AS IsType25 FROM SalesTable WHERE [some stuff here] This is horrible to read/debug and I hate it!! I've tried a few different ways of simplifying this but have been unable to get it to work. The closest I have come is to have a third table holding the definition of the types with the values for each field and the type number, this can be joined to the tables to give me the full values but I can't work out a way to cope with multiple values for each field. Finally the question: Is there a standard way this can be done or an easier/neater method other than one column for each type of target? I know this is a complex problem so if anything is unclear please let me know. Edit - What I need to get: At the very end of the process I need to have targets displayed with actual sales: Type Year Month Salesperson TargetQty ActualQty 2 2012 8 James 2000 2809 2 2012 9 Ian 6500 6251 Each row of the sales table could potentially satisfy 8 of the types. Some more points: I have 5 different columns that need to be defined against the targets (or set to NULL to include any value) I have between 30 and 40 different types that need to be defined, several of the columns could contain as many as 10 different values For point 2, if I am using a row for each permutation of values, 2 columns with 10 values each would give me 100 rows for each sales person for each month which is a lot but if this is the only way to define multiple values I will have to do this. Sorry if this makes no sense!

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  • The most efficient method of drawing multiple quads in OpenGL

    - by CPatton
    I'm not very keen with OpenGL and I was wondering if someone could give me some insight on this. I'm a 'seasoned' programmer, I've read the redbook about VBOs and the like, but I was wondering from a more experienced person about the best/most efficient way of achieving this. I've been producing this 2d tile-based game engine to be used in several projects. I have a class called "ScreenObject" which is mainly composed of a Dictionary<Point, Tile> The Point key is to show where to render the Tile on the screen, and the Tile contains one or more textures to be drawn at that point. This ScreenObject is where the tiles will be modified, deleted, added, etc.. My original method of drawing the tiles in the testing I've done was to iterate through the ScreenObject and draw each quad at each location separately. From what I've read, this is a massive waste of resources. It wasn't horribly slow in the testing, but after I've completed the animation classes and effect classes, I'm sure it would be extremely slow. And one last thing, if you wouldn't mind.. As I said before, the Tile class can contain multiple textures to be drawn at the Point location on the screen. I recognize possibly two options for me here. Either add a quad at that location for each texture to be drawn, or, somehow.. use a multiple texture for the same quad (if it's possible). Even if each tile contained one texture only, that would be 64 quads to be drawn on the screen. Most of the tiles will contain 2-5 textures, so the number of total quads would increase dramatically with this method. Would it be feasible to add a quad for each new texture, or am I ignoring a better way to do this? Just need some help understanding this if you don't mind :) I've tried to be as concise as possible, and I'd greatly appreciate any responses.. and even some criticism. Programming is often a learning process and one who develops seems to never stops learning. Thanks for your time.

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  • Erasing and modifying elements in Boost MultiIndex Container

    - by Sarah
    I'm trying to use a Boost MultiIndex container in my simulation. My knowledge of C++ syntax is very weak, and I'm concerned I'm not properly removing an element from the container or deleting it from memory. I also need to modify elements, and I was hoping to confirm the syntax and basic philosophy here too. // main.cpp ... #include <boost/multi_index_container.hpp> #include <boost/multi_index/hashed_index.hpp> #include <boost/multi_index/member.hpp> #include <boost/multi_index/ordered_index.hpp> #include <boost/multi_index/mem_fun.hpp> #include <boost/tokenizer.hpp> #include <boost/shared_ptr.hpp> ... #include "Host.h" // class Host, all members private, using get fxns to access using boost::multi_index_container; using namespace boost::multi_index; typedef multi_index_container< boost::shared_ptr< Host >, indexed_by< hashed_unique< const_mem_fun<Host,int,&Host::getID> > // ordered_non_unique< BOOST_MULTI_INDEX_MEM_FUN(Host,int,&Host::getAge) > > // end indexed_by > HostContainer; typedef HostContainer::nth_index<0>::type HostsByID; int main() { ... HostContainer allHosts; Host * newHostPtr; newHostPtr = new Host( t, DOB, idCtr, 0, currentEvents ); allHosts.insert( boost::shared_ptr<Host>(newHostPtr) ); // allHosts gets filled up int randomHostID = 4; int newAge = 50; modifyHost( randomHostID, allHosts, newAge ); killHost( randomHostID, allHosts ); } void killHost( int id, HostContainer & hmap ){ HostsByID::iterator it = hmap.find( id ); cout << "Found host id " << (*it)->getID() << "Attempting to kill. hmap.size() before is " << hmap.size() << " and "; hmap.erase( it ); // Is this really erasing (freeing from mem) the underlying Host object? cout << hmap.size() << " after." << endl; } void modifyHost( int id, HostContainer & hmap, int newAge ){ HostsByID::iterator it = hmap.find( id ); (*it) -> setAge( newAge ); // Not actually the "modify" function for MultiIndex... } My questions are In the MultiIndex container allHosts of shared_ptrs to Host objects, is calling allHosts.erase( it ) on an iterator to the object's shared_ptr enough to delete the object permanently and free it from memory? It appears to be removing the shared_ptr from the container. The allhosts container currently has one functioning index that relies on the host's ID. If I introduce an ordered second index that calls on a member function (Host::getAge()), where the age changes over the course of the simulation, is the index always going to be updated when I refer to it? What is the difference between using the MultiIndex's modify to modify the age of the underlying object versus the approach I show above? I'm vaguely confused about what is assumed/required to be constant in MultiIndex. Thanks in advance. Update Here's my attempt to get the modify syntax working, based on what I see in a related Boost example. struct update_age { update_age():(){} // have no idea what this really does... elicits error void operator() (boost::shared_ptr<Host> ptr) { ptr->incrementAge(); // incrementAge() is a member function of class Host } }; and then in modifyHost, I'd have hmap.modify(it,update_age). Even if by some miracle this turns out to be right, I'd love some kind of explanation of what's going on.

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  • Is it worth moving from stored procedures to linq ?

    - by Josef
    I'm looking at standardizing programming in an organisaiton. Half uses stored procedures and the other half Linq. From what i've read there is still some debate going on on this topic. My concern is that MS is trying to slip in it's own proprietry query language 'linq' to make SQL redundant. If a few years back microsoft had tried to win customers from oracle and sybase with their MSSQL database and stated that it didn't use SQL by their own proprietry query langues ie linq. I doubt many would have switched. I believe that is exactly what is happening now by introducting it into the applicaiton business layer. I have used MS for many years but there is one gripe that I have with them and that is that they change their direction a lot. By a lot I mean new releases of .net, silverlight etc are more than 30% different from previous version. So by the time you become productive a new release is on the way. As things stand now a web developer using .net would need to know either vb.net or c#, xml, xaml,javascript,html, sql and now linq. That doesn't make for good productivity in my books. My concern is that once we all start using linq MS will start changing it between releases. and it will become an ever changing landscape. I believe that 'linq to sql' has already been deprecated. At leas with SQL we are dealing with a more stable and standardized language. Are we looking at a programming revolution or a marketing campaign? As far as I know other languages like Cobol have stayed the same for years. A cobol program from 20 years ago could pick up todays code and start working on it. Could a Vb3 person work on a modern .net web app ? Would these large changes need to be made if the underlying original foundation had been sound ? I worry about following MS shaking roadmap with it's deadends and double backs. are there any architects out there who feel the same ? regards Josef

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  • Offline backup synchronization

    - by Pavan Kumar
    There is a Central Server running Windows Server 2003 and SQL Server 2005 and there are 7 client machines situated in various places and has XP Pro & SQL Server 2005 installed in all of them. They are not interconnected so they are physically seperate. One person goes to each of these centers maybe twice a month and takes the backup (Full database consisting of mdf and ldf files) with a pen drive and brings it to the Central server which contains the central database holding same schema as all the other client databases. I need to synchronize each backup database (belonging to different centers) one by one to update the existing data or inserting new data in the central database . The solution i got was Replication. The pendrive is brought to central server consisting of 7 instances of the databases and then the databases is attached to the central server one by one to the same SQL Server where the central database exists. Then my idea was to replicate the backup database one by one i.e using single subscription (Central Database) and multiple publication ( i.e 7 instances of databases in my case) toplogy by performing replication locally (i.e in the same machine). So i tried to develop a UI in C# .Net to programatically run the Transactional Replication with push subscription using RMO Programming (which is incomplete as of now because there is no point in developing when you already know it is not the solution). Transactional Replication can either be set to initialize with a snapshot or without a snapshot. If i go for the first option i.e with a snapshot , the data whatever is present in Central Database is overwritten by the new data . So the data present initially in the central database is lost. If i try to initialize without snapshot , no data (the data already has the updated and new data) will be sent from the backup database to server. The replication will work in a scenario where any incremental changes is done only after you set the replication . So the initial data whatever was present in the backup database when setting up the replication will not be replicated when running the snapshot agent for the first time to synchronize. Only changes in the backup database thereafter will be reflected to the central database .(Remember I am not going to insert new data or make any changes to the backup database after i attach it to the Central Server. ) So this solution is not feasible. I want a solution for synchronizing from one client database to central database present in the same machine using C#.NET. If you can provide me small example maybe with two databases(with same schema) DB1(Client) to DB2(Server) consisting of one or two tables it will be very helpful. The synchronization is not bidirectional.I want to only update existing data or insert new data from DB1 to DB2 (DB2 may contain some data initially). Thanks and Regards Pavan

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  • Really "wow" them in the interview

    - by Juliet
    Let me put it to you this way: I'm a top-notch programmer, but a notoriously bad interviewee. I've flunked 3 interviews consecutively because I get so nervous that my voice tightens at least 2 octaves higher and I start visibly shaking -- mind you, I can handle whatever technical questions the interviewer throws at me in that state, but I think it looks bad to come off as a quivering, squeaky-voiced young woman during a job interview. I've just got the personality type of a shy computer programmer. No matter how technical I am, I'm going to get passed up in favor of a smooth talker. I have another interview coming up shortly, and I want to really impress the company. Here are my trouble spots: What can I do to be less nervous during my interview? I always get really excited when I hear I have a face-to-face interview, but get more and more anxious as D-Day the interview approaches. My employers wants me to explain what I used to do at my prior employment. I'm a very chatty person and tend to talk/squeak for 10 minutes at a time. How long or short should I time my answers? On that note, when I'm explaining what I did at prior jobs, what exactly is my interviewer looking for? At some point, my interviewer will ask "do you have any questions for me while you're here?" I should, but what kinds of questions should I ask to show that I'm interested in being employed? My interviewer always asks why I'm looking for a new job. The real reason is that my present salary is $27K/yr [Edit to add: and I've yet to get a raise since I started], and I want to make more money -- otherwise the work environment is fine. How do I sugarcoat "I want to make more money" into something that sounds nicer? I have only one prior programmer job, and I've worked there for 18 months, but I have the skill of someone with 4 to 6 years of experience. What can I say to compete against applicants with more work experience? I took a low-paying $27K/yr programming job just to get my foot in IT, and I've been trying to leverage that job as a stepping stone to better opportunities. I get interviews because I consistently out-score senior-level developers in aptitude tests, and my desired salary range is right in the ballpark of what most companies want to offer. Unfortunately, while I've been a programming as a hobby for 10 years and I'm geared to graduate with my BA in Comp Sci in May '09, employers see me as a junior-level programmer with no degree. I want to prove them wrong and get a job that matches my skill level. I'd appreciate any advice anyone has to offer, especially if they can help me get a better job in the process.

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  • "ResolveAssemblyReference" task fails and System.BadImageFormatException, but assembly isn't used an

    - by bdwakefield
    I am getting an error about the assembly "C:\Ora10g\bin\Zip.exe". The trouble is this solution does NOT use anything in Oracle at all. I could not find a single reference to 10g anywhere in the project. I inherited this from another person who left our group. He never had this issue. Another member of my team said he got this before but reinstalling the client portion of 10g fixed it. No such luck there. I even tried using WinGrep to search the entire solution folder for "Ora10g" but it wasn't there. Any ideas? I can't build this solution until I can figure out how to get rid of this false reference to Oracle. VS 2005 solution. Contains a couple WinForm apps, a couple class libraries, and a web service. The error occurs in the main class library project. Here is the error message: Error 1 The "ResolveAssemblyReference" task failed unexpectedly. System.BadImageFormatException: Could not load file or assembly 'C:\Ora10g\bin\Zip.exe' or one of its dependencies. The module was expected to contain an assembly manifest. File name: 'C:\Ora10g\bin\Zip.exe' at System.Reflection.AssemblyName.nGetFileInformation(String s) at System.Reflection.AssemblyName.GetAssemblyName(String assemblyFile) at Microsoft.Build.Shared.AssemblyNameExtension.GetAssemblyNameEx(String path) at Microsoft.Build.Tasks.SystemState.GetAssemblyName(String path) at Microsoft.Build.Tasks.Resolver.FileMatchesAssemblyName(AssemblyNameExtension assemblyName, Boolean isPrimaryProjectReference, Boolean wantSpecificVersion, Boolean allowMismatchBetweenFusionNameAndFileName, String pathToCandidateAssembly, ResolutionSearchLocation searchLocation) at Microsoft.Build.Tasks.Resolver.ResolveAsFile(String fullPath, AssemblyNameExtension assemblyName, Boolean isPrimaryProjectReference, Boolean wantSpecificVersion, Boolean allowMismatchBetweenFusionNameAndFileName, ArrayList assembliesConsideredAndRejected) at Microsoft.Build.Tasks.Resolver.ResolveFromDirectory(AssemblyNameExtension assemblyName, Boolean isPrimaryProjectReference, Boolean wantSpecificVersion, String[] executableExtensions, String directory, ArrayList assembliesConsideredAndRejected) at Microsoft.Build.Tasks.AssemblyFoldersResolver.Resolve(AssemblyNameExtension assemblyName, String rawFileNameCandidate, Boolean isPrimaryProjectReference, Boolean wantSpecificVersion, String[] executableExtensions, String hintPath, String assemblyFolderKey, ArrayList assembliesConsideredAndRejected, String& foundPath, Boolean& userRequestedSpecificFile) at Microsoft.Build.Tasks.AssemblyResolution.ResolveReference(IEnumerable`1 jaggedResolvers, AssemblyNameExtension assemblyName, String rawFileNameCandidate, Boolean isPrimaryProjectReference, Boolean wantSpecificVersion, String[] executableExtensions, String hintPath, String assemblyFolderKey, ArrayList assembliesConsideredAndRejected, String& resolvedSearchPath, Boolean& userRequestedSpecificFile) at Microsoft.Build.Tasks.ReferenceTable.ResolveReference(AssemblyNameExtension assemblyName, String rawFileNameCandidate, Reference reference) at Microsoft.Build.Tasks.ReferenceTable.ResolveAssemblyFilenames() at Microsoft.Build.Tasks.ReferenceTable.ComputeClosure() at Microsoft.Build.Tasks.ReferenceTable.ComputeClosure(DependentAssembly[] remappedAssembliesValue, ITaskItem[] referenceAssemblyFiles, ITaskItem[] referenceAssemblyNames, ArrayList exceptions) at Microsoft.Build.Tasks.ResolveAssemblyReference.Execute(FileExists fileExists, DirectoryExists directoryExists, GetDirectories getDirectories, GetAssemblyName getAssemblyName, GetAssemblyMetadata getAssemblyMetadata, GetRegistrySubKeyNames getRegistrySubKeyNames, GetRegistrySubKeyDefaultValue getRegistrySubKeyDefaultValue, GetLastWriteTime getLastWriteTime) at Microsoft.Build.Tasks.ResolveAssemblyReference.Execute() at Microsoft.Build.BuildEngine.TaskEngine.ExecuteTask(ExecutionMode howToExecuteTask, Hashtable projectItemsAvailableToTask, BuildPropertyGroup projectPropertiesAvailableToTask, Boolean& taskClassWasFound) WRN: Assembly binding logging is turned OFF. To enable assembly bind failure logging, set the registry value [HKLM\Software\Microsoft\Fusion!EnableLog] (DWORD) to 1. Note: There is some performance penalty associated with assembly bind failure logging. To turn this feature off, remove the registry value [HKLM\Software\Microsoft\Fusion!EnableLog].

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  • NoSQL DB for .Net document-based database (ECM)

    - by Dane
    I'm halfway through coding a basic multi-tenant SaaS ECM solution. Each client has it's own instance of the database / datastore, but the .Net app is single instance. The documents are pretty much read only (i.e. an image archive of tiffs or PDFs) I've used MSSQL so far, but then started thinking this might be viable in a NoSQL DB (e.g. MongoDB, CouchDB). The basic premise is that it stores documents, each with their own particular indexes. Each tenant can have multiple document types. e.g. One tenant might have an invoice type, which has Customer ID, Invoice Number and Invoice Date. Another tenant might have an application form, which has Member Number, Application Number, Member Name, and Application Date. So far I've used the old method which Sharepoint (used?) to use, and created a document table which has int_field_1, int_field_2, date_field_1, date_field_2, etc. Then, I've got a "mapping" table which stores the customer specific index name, and the database field that will map to. I've avoided the key-value pair model in the DB due to volume of documents. This way, we can support multiple document types in the one table, and get reasonably high performance out of it, and allow for custom document type searches (i.e. user selects a document type, then they're presented with a list of search fields). However, a NoSQL DB might make this a lot simpler, as I don't need to worry about denormalizing the document. However, I've just got concerns about the rest of the data around a document. We store an "action history" against the document. This tracks views, whether someone emails the document from within the system, and other "future" functionality (e.g. faxing). We have control over the document load process, so we can manipulate the data however it needs to be to get it in the document store (e.g. assign unique IDs). Users will not be adding in their own documents, so we shouldn't need to worry about ACID compliance, as the documents are relatively static. So, my questions I guess : Is a NoSQL DB a good fit Is MongoDB the best for Asp.Net (I saw Raven and Velocity, but they're still kinda beta) Can I store a key for each document, and then store the action history in a MSSQL DB with this key? I don't need to do joins, it would be if a person clicks "View History" against a document. How would performance compare between the two (NoSQL DB vs denormalized "document" table) Volumes would be up to 200,000 new documents per month for a single tenant. My current scaling plan with the SQL DB involves moving the SQL DB into a cluster when certain thresholds are reached, and then reviewing partitioning and indexing structures.

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  • JavaScript: Doing some stuff right before the user exits the page

    - by Mike
    I have seen some questions here regarding what I want to achieve and have based what I have so far on those answer. But there is a slight misbehavior that is still irritating me. What I have is sort of a recovery feature. Whenever you are typing text, the client sends a sync request to the server every 45 seconds. It does 2 things. First, it extends the lease the client has on the record (only one person may edit at one time) for another 60 seconds. Second, it sends the text typed so far to the server in case the server crashes, internet connection fails, etc. In that case, the next time the user enters our application, the user is notified that something has gone wrong and that some text was recovered. Think of Microsoft or OpenOffice recovery whenever they crash! Of course, if the user leaves the page willingly, the user does not need to be notified and as a result, the recovery is deleted. I do that final request via a beforeunload event. Everything went fine until I was asked to make a final adjustment... The same behavior you have here at stack overflow when you exit the editor... a confirm dialogue. This works so far, BUT, the confirm dialogue is shown twice. Here is the code. The event if (local.sync.autosave_textelement) { window.onbeforeunload = exitConfirm; } The function function exitConfirm() { var local = Core; if (confirm('blub?')) { local.sync.autosave_destroy = true; sync(false); return true; } else { return false; } }; Some problem irrelevant clarifications: Core is a global Object that contains a lot of variables that are used everywhere. sync makes an ajax request. The values are based on the values that the Core.sync object contains. The parameter determines if the call should be async (default) or sync.

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  • properly setting email subject line delivered from email form

    - by DC1
    I have a email form for my website but here is the issue: when i receive an email, the subject line in my inbox shows whatever the user inputted as subject in the form. id like to override that so that whenever an email comes in. the subject in the email header is always "an inquiry from your website". In the message body, sure i don't mind their specific subject they entered but when I receive an email, id like consistency in my inbox. this is the current code: <?php session_start(); if(isset($_POST['Submit'])) { if( $_SESSION['chapcha_code'] == $_POST['chapcha_code'] && !empty($_SESSION['chapcha_code'] ) ) { $youremail = 'xxxxxxxxx'; $fromsubject = 'An inquiry from your website'; $title = $_POST['title']; $fname = $_POST['fname']; $lname = $_POST['lname']; $mail = $_POST['mail']; $address = $_POST['address']; $city = $_POST['city']; $zip = $_POST['zip']; $country = $_POST['country']; $phone = $_POST['phone']; $subject = $_POST['subject']; $message = $_POST['message']; $headers = "From: $nome <$mail>\r\n"; $to = $youremail; $mailsubject = 'Message received from'.$fromsubject.' Contact Page'; $body = $fromsubject.' The person that contacted you is '.$fname.' '.$lname.' Address: '.$address.' '.$city.', '.$zip.', '.$country.' Phone Number: '.$phone.' E-mail: '.$mail.' Subject: '.$subject.' Message: '.$message.' |---------END MESSAGE----------|'; echo "Thank you for inquiring. We will contact you shortly.<br/>You may return to our <a href='/index.html'>Home Page</a>"; mail($to, $subject, $body, $headers); unset($_SESSION['chapcha_code']); } else { echo 'Sorry, you have provided an invalid security code'; } } else { echo "You must write a message. </br> Please visit our <a href='/contact.html'>Contact Page</a> and try again."; } ?>

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  • Signals and threads - good or bad design decision?

    - by Jens
    I have to write a program that performs highly computationally intensive calculations. The program might run for several days. The calculation can be separated easily in different threads without the need of shared data. I want a GUI or a web service that informs me of the current status. My current design uses BOOST::signals2 and BOOST::thread. It compiles and so far works as expected. If a thread finished one iteration and new data is available it calls a signal which is connected to a slot in the GUI class. My question(s): Is this combination of signals and threads a wise idea? I another forum somebody advised someone else not to "go down this road". Are there potential deadly pitfalls nearby that I failed to see? Is my expectation realistic that it will be "easy" to use my GUI class to provide a web interface or a QT, a VTK or a whatever window? Is there a more clever alternative (like other boost libs) that I overlooked? following code compiles with g++ -Wall -o main -lboost_thread-mt <filename>.cpp code follows: #include <boost/signals2.hpp> #include <boost/thread.hpp> #include <boost/bind.hpp> #include <iostream> #include <iterator> #include <string> using std::cout; using std::cerr; using std::string; /** * Called when a CalcThread finished a new bunch of data. */ boost::signals2::signal<void(string)> signal_new_data; /** * The whole data will be stored here. */ class DataCollector { typedef boost::mutex::scoped_lock scoped_lock; boost::mutex mutex; public: /** * Called by CalcThreads call the to store their data. */ void push(const string &s, const string &caller_name) { scoped_lock lock(mutex); _data.push_back(s); signal_new_data(caller_name); } /** * Output everything collected so far to std::out. */ void out() { typedef std::vector<string>::const_iterator iter; for (iter i = _data.begin(); i != _data.end(); ++i) cout << " " << *i << "\n"; } private: std::vector<string> _data; }; /** * Several of those can calculate stuff. * No data sharing needed. */ struct CalcThread { CalcThread(string name, DataCollector &datcol) : _name(name), _datcol(datcol) { } /** * Expensive algorithms will be implemented here. * @param num_results how many data sets are to be calculated by this thread. */ void operator()(int num_results) { for (int i = 1; i <= num_results; ++i) { std::stringstream s; s << "["; if (i == num_results) s << "LAST "; s << "DATA " << i << " from thread " << _name << "]"; _datcol.push(s.str(), _name); } } private: string _name; DataCollector &_datcol; }; /** * Maybe some VTK or QT or both will be used someday. */ class GuiClass { public: GuiClass(DataCollector &datcol) : _datcol(datcol) { } /** * If the GUI wants to present or at least count the data collected so far. * @param caller_name is the name of the thread whose data is new. */ void slot_data_changed(string caller_name) const { cout << "GuiClass knows: new data from " << caller_name << std::endl; } private: DataCollector & _datcol; }; int main() { DataCollector datcol; GuiClass mc(datcol); signal_new_data.connect(boost::bind(&GuiClass::slot_data_changed, &mc, _1)); CalcThread r1("A", datcol), r2("B", datcol), r3("C", datcol), r4("D", datcol), r5("E", datcol); boost::thread t1(r1, 3); boost::thread t2(r2, 1); boost::thread t3(r3, 2); boost::thread t4(r4, 2); boost::thread t5(r5, 3); t1.join(); t2.join(); t3.join(); t4.join(); t5.join(); datcol.out(); cout << "\nDone" << std::endl; return 0; }

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