Search Results

Search found 21343 results on 854 pages for 'pass by reference'.

Page 658/854 | < Previous Page | 654 655 656 657 658 659 660 661 662 663 664 665  | Next Page >

  • passing hashes to a subroutine

    - by Vishalrix
    In one of my main( or primary) routines,I have two or more hashes. I want the subroutine foo() to recieve these possibly-multiple hashes as distinct hashes. Right now I have no preference if they go by value, or as references. I am struggling with this for the last many hours and would appreciate help, so that I dont have to leave perl for php! ( I am using mod_perl, or will be) Right now I have got some answer to my requirement, shown here From http://forums.gentoo.org/viewtopic-t-803720-start-0.html # sub: dump the hash values with the keys '1' and '3' sub dumpvals { foreach $h (@_) { print "1: $h->{1} 3: $h->{3}\n"; } } # initialize an array of anonymous hash references @arr = ({1,2,3,4}, {1,7,3,8}); # create a new hash and add the reference to the array $t{1} = 5; $t{3} = 6; push @arr, \%t; # call the sub dumpvals(@arr); I only want to extend it so that in dumpvals I could do something like this: foreach my %k ( keys @_[0]) { # use $k and @_[0], and others } The syntax is wrong, but I suppose you can tell that I am trying to get the keys of the first hash ( hash1 or h1), and iterate over them. How to do it in the latter code snippet above?

    Read the article

  • C++ .NET DLL vs C# Managed Code ? (File Encrypting AES-128+XTS)

    - by Ranhiru
    I need to create a Windows Mobile Application (WinMo 6.x - C#) which is used to encrypt/decrypt files. However it is my duty to write the encryption algorithm which is AES-128 along with XTS as the mode of operation. RijndaelManaged just doesn't cut it :( Very much slower than DES and 3DES CryptoServiceProviders :O I know it all depends on how good I am at writing the algorithm in the most efficient way. (And yes I my self have to write it from scratch but i can take a look @ other implementations) Nevertheless, does writing a C++ .NET DLL to create the encryption/decryption algorithm + all the file handling and using it from C# have a significant performance advantage OVER writing the encryption algorithm + file handling in completely managed C# code? If I use C++ .NET to create the encryption algorithm, should I use MFC Smart Device DLL or ATL? What is the difference and is there any impact on which one I choose? And can i just add a reference to the C++ DLL from C# or should I use P/Invoke? I am fairly competent with C# than C++ but performance plays a major role as I have convinced my lecturers that AES is a very efficient cryptographic algorithm for resource constrained devices. Thanx a bunch :)

    Read the article

  • Difficulties using custom control - RichTextEditor

    - by Chris
    I am working on a school project that uses ASP.NET. I found this TextEditor control ( http://blogs.msdn.com/kirti/archive/2007/11/10/rich-text-editor-is-here.aspx ) that I am trying to include but it isn't working. The error I am getting is: Error Rendering Control - TextEditor. An unhandled exception has occurred. Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index. I see this error when I go Design part of the editor. I just don't understand this error at all. Also I am a lil bit confused as there is no parameter called index. :( What I have done is reference the binary in my project and then on the page I am trying to use it have registered its namespace and assembly with this line: <%@ Register Assembly="RichTextEditor" Namespace="AjaxControls" TagPrefix="rtt" %> I then go ahead and try to add the control to the page with this line of code: <rtt:richtexteditor ID="TextEditor" Theme="Blue" runat="server" /> Any help would be much appreciated. I haven't done anything like add a custom control before.

    Read the article

  • how to write this typical mysql query( ho to use subquery column into main query)

    - by I Like PHP
    I HAVE TWO TABLES shown below table_joining id join_id(PK) transfer_id(FK) unit_id transfer_date joining_date 1 j_1 t_1 u_1 2010-06-05 2010-03-05 2 j_2 t_2 u_3 2010-05-10 2010-03-10 3 j_3 t_3 u_6 2010-04-10 2010-01-01 4 j_5 NULL u_3 NULL 2010-06-05 5 j_6 NULL u_4 NULL 2010-05-05 table_transfer id transfer_id(PK) pastUnitId futureUnitId effective_transfer_date 1 t_1 u_3 u_1 2010-06-05 2 t_2 u_6 u_1 2010-05-10 3 t_3 u_5 u_3 2010-04-10 now i want to know total employee detalis( using join_id) which are currently working on unit u_3 . means i want only join_id j_1 (has transfered but effective_transfer_date is future date, right now in u_3) j_2 ( tansfered and right now in `u_3` bcoz effective_transfer_date has been passed) j_6 ( right now in `u_3` and never transfered) what i need to take care of below steps( as far as i know ) <1> first need to check from table_joining whether transfer_id is NULL or not <2> if transfer_id= is NULL then see unit_id=u_3 where joining_date <=CURDATE() ( means that person already joined u_3) <3> if transfer_id is NOT NULL then go to table_transfer using transfer_id (foreign key reference) <4> now see the effective_transfer_date regrading that transfer_id whether effective_transfer_date<=CURDATE() <5> if transfer date has been passed(means transfer has been done) then return futureUnitID otherwise return pastUnitID i used two separate query but don't know how to join those query?? for step <1 ans <2 SELECT unit_id FROM table_joining WHERE joining_date<=CURDATE() AND transfer_id IS NULL AND unit_id='u_3' for step<5 SELECT IF(effective_transfer_date <= CURDATE(),futureUnitId,pastUnitId) AS currentUnitID FROM table_transfer // here how do we select only those rows which have currentUnitID='u_3' ?? please guide me the process?? i m just confused with JOINS. i think using LEFT JOIN can return the data i need, but i m not getting how to implement ...please help me. Thanks for helping me alwayz

    Read the article

  • ASP.Net ListView and event handling.

    - by Neil
    I have an .ascx which contains a listview. Let's call it the parent. Within its ItemTemplate I reference a second .ascx which is basically another listview, let's call it the child. On the parent, the child control is wrapped in a placeholder tag. I use this place holder tag to show and hide the child. Psuedo code: The child listview has a 'close' button in its Layout Template. Let's call it "btnClose" with an onClick event of "btnClose_Click". I want to use this button to set the visibility of the containing placeholder. I'm trying to avoid doing something like using PlaceHolder plhChild = (PlaceHolder)childListCtl.NamingContainer since I can't guarantee every instance of the child .ascx will be contained within a placeholder. I tried creating an event in the child that could be subscribed to. Psuedo code: public delegate CloseButtonHandler(); public event CloseButtonHandler CloseButtonEvent; And in the actual btnClose_Click(Object sender, EventArgs e) event I have: if (CloseButtonEvent != null) CloseButtonEvent(); My problem is that the delegate CloseButtonEvent is always null. I've tried assigning the delegate in the listview's OnDatabound event of the parent and on the click event, to set the plhChild.visible = true, and I've stepped through the code and know the delegate instantiation works in both place, but again, when it gets to the btnClose_Click event on the child, the delegate is null. Any help would be appreciated. Neil

    Read the article

  • Javacsript in PHP code

    - by user147685
    Hi all, I found this code on the internet on how to to display message/pop up box. <? echo "<script language=\"JavaScript\">\n"; echo "alert('$msg1')"; echo "alert('$msg2')"; </script>"; ?> AND <? echo "<script>alert('$msg1' )</script>" <? I want to display messages to the user by popup message. all the messages will be appears in one message box. For above example, the message will be appeared in two box. Can it be done in all in one box? I try using '\n' or 'br'...also cannot or i did it wrongly? any idea?? Is there any reference or tutorial on this? really apreaciate.. thx all..

    Read the article

  • Daylight Savings Handling in DateDiff() in MS Access?

    - by PowerUser
    I am fully aware of DateDiff()'s inability to handle daylight savings issues. Since I often use it to compare the number of hours or days between 2 datetimes several months apart, I need to write up a solution to handle DST. This is what I came up with, a function that first subtracts 60 minutes from a datetime value if it falls within the date ranges specified in a local table (LU_DST). Thus, the usage would be: datediff("n",Conv_DST_to_Local([date1]),Conv_DST_to_Local([date2])) My question is: Is there a better way to handle this? I'm going to make a wild guess that I'm not the first person with this question. This seems like the kind of thing that should have been added to one of the core reference libraries. Is there a way for me to access my system clock to ask it if DST was in effect at a certain date & time? Function Conv_DST_to_Local(X As Date) As Date Dim rst As DAO.Recordset Set rst = CurrentDb.OpenRecordset("LU_DST") Conv_DST_to_Local = X While rst.EOF = False If X > rst.Fields(0) And X < rst.Fields(1) Then Conv_DST_to_Local = DateAdd("n", -60, X) rst.MoveNext Wend End Function Notes I have visited and imported the BAS file of http://www.cpearson.com/excel/TimeZoneAndDaylightTime.aspx. I spent at least an hour by now reading through it and, while it may do its job well, I can't figure out how to modify it to my needs. But if you have an answer using his data structures, I'll take a look. Timezones are not an issue since this is all local time.

    Read the article

  • Class/Model Level Validation (as opposed to Property Level)? (ASP.NET MVC 2.0)

    - by Erx_VB.NExT.Coder
    Basically, what the title says. I have several properties that combine together to really make one logical answer, and i would like to run a server-side validation code (that i write) which take these multiple fields into account and hook up to only one validation output/error message that users see on the webpage. I looked at scott guthries method of extending an attribute and using it in yoru dataannotations declarations, but, as i can see, there is no way to declare a dataannotations-style attribute on multiple properties, and you can only place the declarations (such as [Email], [Range], [Required]) over one property :(. i have looked at the PropertiesMustMatchAttribute in the default mvc 2.0 project that appears when you start a new project, this example is as useful as using a pair of pins to check your motor oil - useless! i have tried this method, however, creating a class level attribute, and have no idea how to display the error from this in my aspx page. i have tried html.ValidationMessage("ClassNameWhereAttributeIsAdded") and a variety of other thing, and it has not worked. and i should mention, there is NOT ONE blog post on doing validation at this level - despite this being a common need in any project or business logic scenario! can anyone help me in having my message displayed in my aspx page, and also if possible a proper document or reference explaining validation at this level?

    Read the article

  • Write a compiler for a language that looks ahead and multiple files?

    - by acidzombie24
    In my language I can use a class variable in my method when the definition appears below the method. It can also call methods below my method and etc. There are no 'headers'. Take this C# example. class A { public void callMethods() { print(); B b; b.notYetSeen(); public void print() { Console.Write("v = {0}", v); } int v=9; } class B { public void notYetSeen() { Console.Write("notYetSeen()\n"); } } How should I compile that? what i was thinking is: pass1: convert everything to an AST pass2: go through all classes and build a list of define classes/variable/etc pass3: go through code and check if there's any errors such as undefined variable, wrong use etc and create my output But it seems like for this to work I have to do pass 1 and 2 for ALL files before doing pass3. Also it feels like a lot of work to do until I find a syntax error (other than the obvious that can be done at parse time such as forgetting to close a brace or writing 0xLETTERS instead of a hex value). My gut says there is some other way. Note: I am using bison/flex to generate my compiler.

    Read the article

  • WCF Certificates without Certificate Store

    - by Kane
    My team is developing a number of WPF plug-ins for a 3rd party thick client application. The WPF plug-ins use WCF to consume web services published by a number of TIBCO services. The thick client application maintains a separate central data store and uses a proprietary API to access the data store. The thick client and WPF plug-ins are due to be deployed onto 10,000 workstations. Our customer wants to keep the certificate used by the thick client in the central data store so that they don't need to worry about re-issuing the certificate (current re-issue cycle takes about 3 months) and also have the opportunity to authorise the use of the certificate. The proposed architecture offers a form of shared secret / authentication between the central data store and the TIBCO services. Whilst I don’t necessarily agree with the proposed architecture our team is not able to change it and must work with what’s been provided. Basically our client wants us to build into our WPF plug-ins a mechanism which retrieves the certificate from the central data store (which will be allowed or denied based on roles in that data store) into memory then use the certificate for creating the SSL connection to the TIBCO services. No use of the local machine's certificate store is allowed and the in memory version is to be discarded at the end of each session. So the question is does anyone know if it is possible to pass an in-memory certificate to a WCF (.NET 3.5) service for SSL transport level encryption? Note: I had asked a similar question (here) but have since deleted it and re-asked it with more information.

    Read the article

  • jquery image hover popup cant detect browser edge and change its direction

    - by Salman
    hi guys i am trying to implement jquery image hover popup but facing a problem when the popup is closer to browser edge it goes beyond its edge i want it to change its direction when it finds that space is not enough to show that popup, i have see this effect in many plugins where popups, tooltips and drop down menus change their direction if they are close to browser window edge can any one guide me in right direction here is the screen shot for reference http://img512.imageshack.us/img512/4990/browseredge.png here is the jquery hover code function imagePreview(){ /* CONFIG */ xOffset = 10; yOffset = 30; // these 2 variable determine popup's distance from the cursor // you might want to adjust to get the right result /* END CONFIG */ $("a.preview").hover(function(e){ this.t = this.title; this.title = ""; var c = (this.t != "") ? "<br>" + this.t : ""; var newName = this.name; //console.log(this.name); newName=newName.replace("/l/","/o/"); //console.log(newName); $("body").append("<p id='preview'><img src='"+ this.name +"' alt='Image preview' style='margin-bottom:5px;'>"+ c +"</p>"); $("#preview img").error(function () { $("#preview img").attr("src" ,newName).css({'width': '400px', 'height': 'auto'}); }); $("#preview") .css("top",(e.pageY - xOffset) + "px") .css("left",(e.pageX + yOffset) + "px") .fadeIn("fast"); }, function(){ this.title = this.t; $("#preview").remove(); }); $("a.preview").mousemove(function(e){ $("#preview") .css("top",(e.pageY - xOffset) + "px") .css("left",(e.pageX + yOffset) + "px"); }); }; any help will be appriciated Thanks Salman

    Read the article

  • Generic allocator class without variadic templates?

    - by rainer
    I am trying to write a generic allocator class that does not really release an object's memory when it is free()'d but holds it in a queue and returns a previously allocated object if a new one is requested. Now, what I can't wrap my head around is how to pass arguments to the object's constructor when using my allocator (at least without resorting to variadic templates, that is). The alloc() function i came up with looks like this: template <typename... T> inline T *alloc(const &T... args) { T *p; if (_free.empty()) { p = new T(args...); } else { p = _free.front(); _free.pop(); // to call the ctor of T, we need to first call its DTor p->~T(); p = new( p ) T(args...); } return p; } Still, I need the code to be compatible with today's C++ (and older versions of GCC that do not support variadic templates). Is there any other way to go about passing an arbitrary amount of arguments to the objects constructor?

    Read the article

  • WPF/SL EventAggregator implementation with durable subscribers behavior?

    - by sha1dy
    Hi. Currently I'm building an application using latest Prism for Silverlight 4. I've a module and in that module I've two views with view models. Also I've a module view with two regions for each view. In module initialization I'm registering my views and view models in Unity container and also register views with corresponding regions. The problem is that views should display something similar to table-detail information - first view shows available entities ans the second view shows detail of selected entity. I need a way how to pass them initial selected entity. Newly created first view doesn't have any selected entity and newly created second view doesn't show any details. Currently I'm doing that this way: In module I create two view models and register them as instances in Unity container and then I register views as types for corresponding regions. Each view subscribes to EntitySelectedEvent from EventAggregator. Module initializer publish this event after initialization and this way two views are selecting the same entity. I know this looks ugly - I tried publishing this event from one of view models but the problems is that EventAggregator in Prism doesn't support durable subscribers - this means that if the second view model didn't subscribe to event before the first view model fired it, it won't receive and event. I know this is a normal behavior of EventAggregator, but I'm looking for a solution when view models can fire events without depending on initialization order of them - that is the first model can fire event before the second model was created and the second model will receive this 'queued' event after subscribing to it. Are there any other messaging implementations for WPF/SL which do support such behavior or using a mediator (in my example it's a module itself) isn't such a bad idea after all? One big problem with mediator is that models must be created right away in initialize and they can't be registered as types in container because this leads again to missing subscribers.

    Read the article

  • XNA 2D mouse picking

    - by Corndog
    I'm working on a simple 2D Real time strategy game using XNA. Right now I have reached the point where I need to be able to click on the sprite for a unit or building and be able to reference the object associated with that sprite. From the research I have done over the last three days I have found many references on how to do "Mouse picking" in 3D which does not seem to apply to my situation. I understand that another way to do this is to simply have an array of all "selectable" objects in the world and when the player clicks on a sprite it checks the mouse location against the locations of all the objects in the array. the problem I have with this approach is that it would become rather slow if the number of units and buildings grows to larger numbers. (it also does not seem very elegant) so what are some other ways I could do this. (Please note that I have also worked over the ideas of using a Hash table to associate the object with the sprite location, and using a 2 dimensional array where each location in the array represents one pixel in the world. once again they seem like rather clunky ways of doing things.)

    Read the article

  • Program Structure Design Tools? (Top Down Design)

    - by Lee Olayvar
    I have been looking to expand my methodologies to better involve Unit testing, and i stumbled upon Behavioral Driven Design (Namely Cucumber, and a few others). I am quite intrigued by the concept as i have never been able to properly design top down, only because keeping track of the design gets lost without a decent way to record it. So on that note, in a mostly language agnostic way, are there any useful tools out there i am (probably) unaware of? Eg, i have often been tempted to try building flow charts for my programs, but i am not sure how much that will help, and it seems a bit confusing to me how i could make a complex enough flow chart to handle the logic of a full program, and all its features.. ie, it just seems like flow charts would be limiting in the design scheme.. or possibly grow to an unmaintainable scale. BDD methods are nice, but with a system that is so tied to structure, tying into the language and unit testing seems like a must (for it to be worth it) and it seems to be hard to find something to work well with both Python and Java (my two main languages). So anyway.. on that note, any comments are much appreciated. I have searched around on here and it seems like top down design is a well discussed topic, but i haven't seen too much reference to tools themselves, eg, flow chart programs, etc. I am on Linux, if it matters (in the case of programs).

    Read the article

  • RegAsm for Class Library Used in VB6 Application

    - by michael.lukatchik
    To be short and to the point, I've built a C# class library that is both COM-Visible and Registered for COM Interop. I've compiled the library, which resulted in the generation of .dll and .tlb files. I have another machine that's running a VB6 application. So, I copied the .dll and .tlb files over to C:/Windows/system32 folder on the machine. I then registered those files using the following: C:\Windows\Microsoft.NET\Framework\v2.0.50727\RegAsm C:\Windows\system32\TestClass.dll /tlb:TestClass.tlb After the files were registered successfully, I added a project reference to the Test.tlb file from inside my VB6 app, then I tried to invoke a method in my new referenced class like so: Dim myObject As TestNamespace.TestClass Set myObject = New TestNamespace.TestClass MsgBox (myObject.TestMethod()) It doesn't work, and I receive a -2147024894 Automation Error. I've read that I shouldn't install the dll into a private folder like system32. I should either be registering in the GAC or I should be registering in another location using the "/codebase" option: C:\Windows\Microsoft.NET\Framework\v2.0.50727\RegAsm C:\TestClass.dll /tlb:TestClass.tlb /codebase Is there any reason I shouldn't be using system32? Past devs that have worked on this project have placed assembly files used by this VB6 project into system32 and there haven't seemed to be any issues. When I register my dll in the system32 location, I get the Automation Error. When I register my dll in another location (i.e. C:/), the method call into my class library from VB6 works as expected. What gives? I should mention that we will NOT be using the GAC to register any DLL's. That's just the way it is. Any help is appreciated. Mike

    Read the article

  • Semantic Grid System, Media Query issue

    - by Andy
    I'm using the Semantic Grid System to build a responsive site. However, something isn't quite right with the media queries that should obviously kick in once it hits a particular screen size. I'll reference what i mean with their example on the website : if I view this on my iPhone for example, given that it is supposed to adjust to a single column structure on a mobile device, it still throws out the web version of the page. That is true for both Safari and Chrome on my iPhone. However, if I use the RWD bookmarklet to check it's appearance at different resolutions it appears as expected for the mobile resolution. Also, ironically, if I resize the page in Safari on my desktop it also adjusts accordingly once I get down to the approriate screen size, but not in Firefox. The media query that it uses once it hits 720px is @media screen and (max-width: 720px) { #maincolumn, #sidebar { .column(12); margin-bottom: 1em; } } and I might be wide of the mark here but I think that must be the issue. But given that this is directly from the semantic.gs website I'm not inclined to question their own code. Any idea what the problem might be?

    Read the article

  • Official names for pointer operators

    - by FredOverflow
    What are the official names for the operators * and & in the context of pointers? They seem to be frequently called dereference operator and address-of operator respectively, but unfortunately, the section on unary operators in the standard does not name them. I really don't want to name & address-of anymore, because & returns a pointer, not an address. (A pointer is a language mechanism, while an address is an implementation detail. Addresses are untyped, while pointers aren't, except for void*.) The standard is very clear about this: The result of the unary & operator is a pointer to its operand. Symmetry suggests to name & reference operator which is a little unfortunate because of the collision with references in C++. The fact that & returns a pointer suggests pointer operator. Are there any official sources that would confirm these (or other) namings?

    Read the article

  • Reordering arguments using recursion (pro, cons, alternatives)

    - by polygenelubricants
    I find that I often make a recursive call just to reorder arguments. For example, here's my solution for endOther from codingbat.com: Given two strings, return true if either of the strings appears at the very end of the other string, ignoring upper/lower case differences (in other words, the computation should not be "case sensitive"). Note: str.toLowerCase() returns the lowercase version of a string. public boolean endOther(String a, String b) { return a.length() < b.length() ? endOther(b, a) : a.toLowerCase().endsWith(b.toLowerCase()); } I'm very comfortable with recursions, but I can certainly understand why some perhaps would object to it. There are two obvious alternatives to this recursion technique: Swap a and b traditionally public boolean endOther(String a, String b) { if (a.length() < b.length()) { String t = a; a = b; b = t; } return a.toLowerCase().endsWith(b.toLowerCase()); } Not convenient in a language like Java that doesn't pass by reference Lots of code just to do a simple operation An extra if statement breaks the "flow" Repeat code public boolean endOther(String a, String b) { return (a.length() < b.length()) ? b.toLowerCase().endsWith(a.toLowerCase()) : a.toLowerCase().endsWith(b.toLowerCase()); } Explicit symmetry may be a nice thing (or not?) Bad idea unless the repeated code is very simple ...though in this case you can get rid of the ternary and just || the two expressions So my questions are: Is there a name for these 3 techniques? (Are there more?) Is there a name for what they achieve? (e.g. "parameter normalization", perhaps?) Are there official recommendations on which technique to use (when)? What are other pros/cons that I may have missed?

    Read the article

  • Sybase: how can I remove non-printable characters from CHAR or VARCHAR fields with SQL?

    - by Kenny Drobnack
    I'm working with a Sybase database that seems to have non-printable characters in some of the string fields and this is throwing off some of our processing code. At first glance, it seemed to only be newlines and carriage returns, but we also have an ASCII code 27 in there - an ESC character, some accented characters, and some other oddities in there. I have no direct access to change the database, so changing the bad data isn't an option, yet. For now I have to make do with just filtering it out. We're trying to export the table data from one database and load it into a database used by another application in a nightly batch process. Ideally, I'd like to have a function that I can pass a list of characters and just have Sybase return the data with those characters removed. I'd like to keep it something we could do in plain SQL if possible. Something like this to remove characters that are ASCII 0 - 31. select str_replace(FIELD1, (0-31), NULL) as FIELD1, str_replace(FIELD2, (0-31), NULL) as FIELD2 from TABLE So far, str_replace is the nearest I can find, but it only allows replacing one string with another. No support for character ranges and won't let me do the above. We're running on Sybase ASE 12.5 on Unix servers.

    Read the article

  • Is there added overhead to looking up a column in a DataTable by name rather than by index?

    - by Ben McCormack
    In a DataTable object, is there added overhead to looking up a column value by name thisRow("ColumnA") rather than by the column index thisRow(0)? In which scenarios might this be an issue. I work on a team that has lots of experience writing VB6 code and I noticed that didn't do column lookups by name for DataTable objects or data grids. Even in .NET code, we use a set of integer constants to reference column names in these types of objects. I asked our team lead why this was so, and he mentioned that in VB6, there was a lot of overhead in looking up data by column name rather than by index. Is this still true for .NET? Example code (in VB.NET, but same applies to C#): Public Sub TestADOData() Dim dt As New DataTable 'Set up the columns in the DataTable ' dt.Columns.Add(New DataColumn("ID", GetType(Integer))) dt.Columns.Add(New DataColumn("Name", GetType(String))) dt.Columns.Add(New DataColumn("Description", GetType(String))) 'Add some data to the data table ' dt.Rows.Add(1, "Fred", "Pitcher") dt.Rows.Add(3, "Hank", "Center Field") 'Method 1: By Column Name ' For Each r As DataRow In dt.Rows Console.WriteLine( _ "{0,-2} {1,-10} {2,-30}", r("ID"), r("Name"), r("Description")) Next Console.WriteLine() 'Method 2: By Column Name ' For Each r As DataRow In dt.Rows Console.WriteLine("{0,-2} {1,-10} {2,-30}", r(0), r(1), r(2)) Next End Sub Is there an case where method 2 provides a performance advantage over method 1?

    Read the article

  • Calling SubmitChanges on DataContext does not update database.

    - by drasto
    In C# ASP.NET MVC application I use Link to SQL to provide data for my application. I have got simple database schema like this: In my controller class I reference this data context called Model (as you can see on the right side of picture in properties) like this: private Model model = new Model(); I've got a table (List) of Series rendered on my page. It renders properly and I was able to add delete functionality to delete Series like this: public ActionResult Delete(int id) { model.Series.DeleteOnSubmit(model.Series.SingleOrDefault(s => s.ID == id)); model.SubmitChanges(); return RedirectToAction("Index"); } Where appropriate action link looks like this: <%: Html.ActionLink("Delete", "Delete", new { id=item.ID })%> Also create (implemented in similar way) works fine. However edit does not work. My edit looks like this: public ActionResult Edit(int id) { return View(model.Series.SingleOrDefault(s => s.ID == id)); } [HttpPost] public ActionResult Edit(Series series) { if (ModelState.IsValid) { UpdateModel(series); series.Title = series.Title + " some string to ensure title has changed"; model.SubmitChanges(); return RedirectToAction("Index"); } I have controlled that my database has a primary key set up correctly. I debugged my application and found out that everything works as expected until the line with model.SubmitChanges();. This command does not apply the changes of Title property(or any other) against the database. Please help.

    Read the article

  • When actually is a closure created?

    - by Jian Lin
    Is it true that a closure is created in the following cases for foo, but not for bar? Case 1: <script type="text/javascript"> function foo() { } </script> foo is a closure with a scope chain with only the global scope. Case 2: <script type="text/javascript"> var i = 1; function foo() { return i; } </script> same as Case 1. Case 3: <script type="text/javascript"> function Circle(r) { this.r = r; } Circle.prototype.foo = function() { return 3.1415 * this.r * this.r } </script> in this case, Circle.prototype.foo (which returns the circle's area) refers to a closure with only the global scope. (this closure is created). Case 4: <script type="text/javascript"> function foo() { function bar() { } } </script> here, foo is a closure with only the global scope, but bar is not a closure (yet), because the function foo is not invoked in the code, so no closure goo is ever created. It will only exist if foo is invoked , and the closure bar will exist until foo returns, and the closure bar will then be garbage collected, since there is no reference to it at all anywhere. So when the function doesn't exist, can't be invoked, can't be referenced, then the closure doesn't exist yet (never created yet). Only when the function can be invoked or can be referenced, then the closure is actually created?

    Read the article

  • How to keep track of a private messaging system using MongoDB?

    - by luckytaxi
    Take facebook's private messaging system where you have to keep track of sender and receiver along w/ the message content. If I were using MySQL I would have multiple tables, but with MongoDB I'll try to avoid all that. I'm trying to come up with a "good" schema that can scale and is easy to maintain. If I were using mysql, I would have a separate table to reference the user and and message. See below ... profiles table user_id first_name last_name message table message_id message_body time_stamp user_message_ref table user_id (FK) message_id (FK) is_sender (boolean) With the schema listed above, I can query for any messages that "Bob" may have regardless if he's the recipient or sender. Now how to turn that into a schema that works with MongoDB. I'm thinking I'll have a separate collection to hold the messages. Problem is, how can I differentiate between the sender and the recipient? If Bob logs in, what do I query against? Depending on whether Bob initiated the email, I don't want to have to query against "sender" and "receiver" just to see if the message belongs to the user.

    Read the article

  • How to invalidate layout of listbox from custom children

    - by Stephen Price
    I have a custom panel for a listbox <ItemsPanelTemplate x:Key="FloatPanelTemplate"> <Controls:FloatPanel x:Name="CardPanel" /> </ItemsPanelTemplate> The panel lays out its children using its X and Y dependency properties. This all works nicely when the FloatPanel is used by itself - I'm using FrameworkPropertyMetadataOptions.AffectsArrange | FrameworkPropertyMetadataOptions.AffectsMeasure on the dependency properties of the child items to tell the FloatPanel to redraw its layout. When I use it in a Listbox (code above) then it draws fine the first time, but when I drag the children (which modifies the item's X and Y) it is not notifying the Listbox that it needs to redraw the FloatPanel's children. I think the issue is related to the fact that each item in the bound collection is wrapped with a ListBoxItem. Hopefully I've described what i'm doing well enough that someone can tell me how to make the panel (or its children) tell it needs to do the Layout routines again. As I said it works once (initial draw) but then dragging items doesn't work (Listbox isnt aware that its children have changed and needs to relayout.) If I drag an item and then resize the window, the listbox does a layout and the items are drawn in their new locations. How do I notify the ListBox (or more importantly the FloatPanel in the ItemsPanelTemplate) that it needs to do a Layout pass?

    Read the article

< Previous Page | 654 655 656 657 658 659 660 661 662 663 664 665  | Next Page >