Search Results

Search found 10201 results on 409 pages for 'virtual desktops'.

Page 371/409 | < Previous Page | 367 368 369 370 371 372 373 374 375 376 377 378  | Next Page >

  • BackgroundWorker acting bizarrely...

    - by vdh_ant
    Hi guys I'm working on some code that calls a service. This service call could fail and if it does I want the system to try again until it works or too much time has passed. I am wondering where I am going wrong as the following code doesn't seem to be working correctly... It randomly only does one to four loops... protected virtual void ProcessAsync(object data, int count) { var worker = new BackgroundWorker(); worker.DoWork += (sender, e) => { throw new InvalidOperationException("oh shiznit!"); }; worker.RunWorkerCompleted += (sender, e) => { //If an error occurs we need to tell the data about it if (e.Error != null) { count++; System.Threading.Thread.Sleep(count * 5000); if (count <= 10) { if (count % 5 == 0) this.Logger.Fatal("LOAD ERROR - The system can't load any data", e.Error); else this.Logger.Error("LOAD ERROR - The system can't load any data", e.Error); this.ProcessAsync(data, count); } } }; worker.RunWorkerAsync(); } Cheers Anthony

    Read the article

  • Is it OK to set state within Event Raising methods?

    - by Greg
    I ran across this pattern in the code of a library I'm using. It sets state within the event raising method, but only if the event is not null. protected virtual void OnMyEvent(EventArgs e) { if(MyEvent != null) { State = "Executing"; // Only sets state if MyEvent != null. MyEvent(this,e); } } Which means that the state is not set when overriding the method: protected override void OnMyEvent(EventArgs e) { base.OnMyEvent(e); Debug.Assert( State == "Executing" ); // This fails } but is only set when handling the event: foo.MyEvent += (o, args) => Debug.Assert(State == "Executing"); // This passes Setting state within the if(MyEvent != null) seems like bad form, but I've checked the Event Design Guidelines and it doesn't mention this. Do you think this code is incorrect? If so, why? (Reference to design guidelines would be helpful). Edit for Context: It's a Control, I'm trying to create subclass of it, and the state that it's setting is calling EnsureChildControls() conditionally based upon there being an event handler. I can call EnsureChildControls() myself, but I consider that something of a hack.

    Read the article

  • C++ templates error: instantiated from 'void TestClass::testMethod(T, std::map) [with T = SomeClass]

    - by pureconsciousness
    Hello there, I've some problem in my code I cannot deal with: #ifndef TESTCLASS_H_ #define TESTCLASS_H_' #include <map> using namespace std; template <typename T> class TestClass { public: TestClass(){}; virtual ~TestClass(){}; void testMethod(T b,std::map<T,int> m); }; template <typename T> void TestClass`<T`>::testMethod(T b,std::map<T,int> m){ m[b]=0; } #endif /*TESTCLASS_H_*/ int main(int argc, char* argv[]) { SomeClass s; TestClass<SomeClass> t; map<SomeClass,int> m; t.testMethod(s,m); } Compiler gives me following error in line m[b]=0; : instantiated from 'void TestClass::testMethod(T, std::map) [with T = SomeClass] Could you help find the problem?? Thanks in advance

    Read the article

  • Implementing a Version check between an Abstract class and it's implementation

    - by Michael Stum
    I have this abstract class and concrete implementation (they are in different assemblies): public abstract class MyAbstractClass { private static readonly int MyAbstractClassVersion = 1; public abstract int ImplementedVersion { get; } protected MyAbstractClass() { CheckVersion(); } private void CheckVersion() { var message = string.Format( "MyAbstractClass implements Version {0}, concrete is Version {1}", RepositoryVersion, ImplementedVersion); if (!MyAbstractClassVersion.Equals(ImplementedVersion)) throw new InvalidOperationException(message); } } public class ConcreteClass : MyAbstractClass { public ConcreteClass() : base() { // ConcreteClass is guaranteed to have // a constructor that calls the base constructor // I just simplified the example } public override int ImplementedVersion { get { return 2; } } } As you see, I call CheckVersion() from the abstract constructor, to get rid of the "virtual member call in base constructor" message, but I am not sure if that's really the way to do it. Sure, it works, but that doesn't mean it will always work, will it? Also, I wonder if I can get the name of the Concrete Type from the CheckVersion() function? I know that adding new abstract members will force an error anyway (System.TypeLoadException) and I'm not sure if I want this type of strict Versioning, but I'm just curious how it would be done properly given only the abstract class and an implementation (I know I could do it by using interfaces and/or a Factory pattern).

    Read the article

  • Why does the VS2005 debugger not report "base." values properly? (was "Why is this if statement fail

    - by Rawling
    I'm working on an existing class that is two steps derived from System.Windows.Forms.Combo box. The class overrides the Text property thus: public override string Text { get { return this.AccessibilityObject.Value; } set { if (base.Text != value) { base.Text = value; } } } The reason given for that "get" is this MS bug: http://support.microsoft.com/kb/814346 However, I'm more interested in the fact that the "if" doesn't work. There are times where "base.Text != value" is true and yet pressing F10 steps straight to the closing } of the "set" and the Text property is not changed. I've seen this both by just checking values in the debugger, and putting a conditional breakpoint on that only breaks when the "if" statement's predicate is true. How on earth can "if" go wrong? The class between this and ComboBox doesn't touch the Text property. The bug above shouldn't really be affecting anything - it says it's fixed in VS2005. Is the debugger showing different values than the program itself sees? Update I think I've found what is happening here. The debugger is reporting value incorrectly (including evaluating conditional breakpoints incorrectly). To see this, try the following pair of classes: class MyBase { virtual public string Text { get { return "BaseText"; } } } class MyDerived : MyBase { public override string Text { get { string test = base.Text; return "DerivedText"; } } } Put a breakpoint on the last return statement, then run the code and access that property. In my VS2005, hovering over base.Text gives the value "DerivedText", but the variable test has been correctly set to "BaseText". So, new question: why does the debugger not handle base properly, and how can I get it to?

    Read the article

  • which sql consumes less memory

    - by prmatta
    Yesterday I asked a question on how to re-write sql to do selects and inserts in batches. I needed to do this to try and consume less virtual memory, since I need to move millions of rows here. The object is to move rows from Table B into Table A. Here are the ways I can think of doing this: SQL #1) INSERT INTO A (x, y, z) SELECT x, y, z FROM B b WHERE ... SQL #2) FOREACH SELECT x,y,z FROM B b WHERE ... INSERT INTO A(x,y,z); END FOREACH; SQL #3) FOREACH SELECT FIRST 2000 x,y,z FROM B b WHERE ... INSERT INTO A(x,y,z); END FOREACH; SQL #4) FOREACH SELECT FIRST 2000 x,y,z FROM B b WHERE ... AND NOT EXISTS IN (SELECT * FROM A) INSERT INTO A(x,y,z); END FOREACH; Are any of the above incorrect? The database is informix 11.5.

    Read the article

  • Context.Items.Add on an XML return type?

    - by Scott Schluer
    So I have the following code contained within an HttpModule in an application I've been asked to support: app.Context.Response.ContentType = "text/xml"; app.Context.Items.Add("IpixRoomId", ipixRoomId); app.Context.Items.Add("IpixId", ipixId); app.Context.Response.Cache.SetCacheability(HttpCacheability.NoCache); app.Context.RewritePath(rewriteUrl, true); What's the purpose of adding data to Context.Items when the content type is XML? EDIT: For clarification, I'm calling up this URL: http://website.com/virtualtour/1971/6284/panorama2flash.swf I assume the SWF file (I know very little about Flash) makes another call to http://website.com/virtualtour/config.xml. The code I pasted above only executes on calls to config.xml. So since it's only the SWF file and config.xml being requested from the server, I'm a little confused. Can the .SWF file have access to HttpContext.Current.Items? Other than the HttpModule, there is no .NET involved in the code, it's a straight request to the SWF file which triggers a call to config.xml but it seems that those Context.Items contain the data needed to make the SWF file display the right virtual tour. I'm just missing where that link happens. It can't happen in the XML, so maybe in Flash?

    Read the article

  • Why can a public class not inherit from a less visible one?

    - by Dan Tao
    I apologize if this question has been asked before. I've searched SO somewhat and wasn't able to find it. I'm just curious what the rationale behind this design was/is. Obviously I understand that private/internal members of a base type cannot, nor should they, be exposed through a derived public type. But it seems to my naive thinking that the "hidden" parts could easily remain hidden while some base functionality is still shared and a new interface is exposed publicly. I'm thinking of something along these lines: Assembly X internal class InternalClass { protected virtual void DoSomethingProtected() { // Let's say this method provides some useful functionality. // Its visibility is quite limited (only to derived types in // the same assembly), but at least it's there. } } public class PublicClass : InternalClass { public void DoSomethingPublic() { // Now let's say this method is useful enough that this type // should be public. What's keeping us from leveraging the // base functionality laid out in InternalClass's implementation, // without exposing anything that shouldn't be exposed? } } Assembly Y public class OtherPublicClass : PublicClass { // It seems (again, to my naive mind) that this could work. This class // simply wouldn't be able to "see" any of the methods of InternalClass // from AssemblyX directly. But it could still access the public and // protected members of PublicClass that weren't inherited from // InternalClass. Does this make sense? What am I missing? }

    Read the article

  • Qtimer not timing out QT, C++

    - by realz
    Hi, I am learning C++ and using QT. I have a small program in which I am trying to update the text of the PushButton every second. The label being current time. I have a timer that should time out every second, but seems like it never does. here's the code. Header File #ifndef _HELLOFORM_H #define _HELLOFORM_H #include "ui_HelloForm.h" class HelloForm : public QDialog { public: HelloForm(); virtual ~HelloForm(); public slots: void textChanged(const QString& text); void updateCaption(); private: Ui::HelloForm widget; }; #endif /* _HELLOFORM_H */ CPP file #include "HelloForm.h" #include <QTimer> #include <QtGui/QPushButton> #include <QTime> HelloForm::HelloForm(){ widget.setupUi(this); widget.pushButton->setText(QTime::currentTime().toString()); widget.pushButton->setFont(QFont( "Times", 9, QFont::Bold ) ); QTimer *timer = new QTimer(this); connect(timer, SIGNAL(timeout()), SLOT(updateCaption())); timer->start(1000); connect(widget.pushButton, SIGNAL(clicked()), qApp, SLOT(quit()) ); connect(widget.nameEdit, SIGNAL(textChanged(const QString&)), this, SLOT(textChanged(const QString&))); } HelloForm::~HelloForm() { } void HelloForm::textChanged(const QString& text) { if (0 < text.trimmed().length()) { widget.helloEdit->setText("Hello " + text.trimmed() + "!"); } else { widget.helloEdit->clear(); } } void HelloForm::updateCaption() { QString myVar; myVar = QTime::currentTime().toString(); widget.pushButton->setText(myVar); } Any help will be greatly appreciated... The PushButton's text never changes...

    Read the article

  • ecommerce - use server side code for hidden values in an html form

    - by bsarmi
    I'm trying to learn how to implement a donation form on a website using virtual merchant. The html code from their developer manual goes like this: <form action="https://www.myvirtualmerchant.com/VirtualMerchant/process.do" method="POST"> Your Total: $5.00 <br/> <input type="hidden" name="ssl_amount" value="5.00"> <br/> <input type="hidden" name="ssl_merchant_id" value="my_virtualmerchant_ID"> <input type="hidden" name="ssl_pin" value="my_PIN"> <input type="hidden" name="ssl_transaction_type" value="ccsale"> <input type="hidden" name="ssl_show_form" value="false"> Credit Card Number: <input type="text" name="ssl_card_number"> <br/> Expiration Date (MMYY): <input type="text" name="ssl_exp_date" size="4"> <br/> <br/> <input type="submit" value="Continue"> </form> I have that in an html file and it works fine, but they suggest that the merchant data (the input type="hidden" values) should be in a Server Side Code. I was looking at cURL but it'a all very new to me and I spent a couple of hours trying to find some guide or some sample code on how to accomplish that. Any suggestions or help is greatly appreciated. Thanks!

    Read the article

  • Which design pattern fits - strategy makes sense ?

    - by user554833
    --Bump *One desperate try to get someone's attention I have a simple database table that stores list of users who have subscribed to folders either by email OR to show up on the site (only on the web UI). In the storage table this is controlled by a number(1 - show on site 2- by email). When I am showing in UI I need to show a checkbox next to each of folders for which the user has subscribed (both email & on site). There is a separate table which stores a set of default subscriptions which would apply to each user if user has not expressed his subscription. This is basically a folder ID and a virtual group name. But, Email subscriptions do not count for applying these default groups. So if no "on site" subscription apply default group. Thats the rule. How about a strategy pattern here (Pseudo code) Interface ISubscription public ArrayList GetSubscriptionData(Pass query object) Public class SubscriptionWithDefaultGroup Implement ArrayList GetSubscriptionData(Pass query object) Public class SubscriptionWithoutDefaultGroup Implement ArrayList GetSubscriptionData(Pass query object) Public class SubscriptionOnlyDefaultGroup Implement ArrayList GetSubscriptionData(Pass query object) does this even make sense? I would be more than glad for receive any criticism / help / notes. I am learning. Cheers

    Read the article

  • Bizarre static_cast trick?

    - by Rob
    While perusing the Qt source code I came across this gem: template <class T> inline T qgraphicsitem_cast(const QGraphicsItem *item) { return int(static_cast<T>(0)->Type) == int(QGraphicsItem::Type) || (item && int(static_cast<T>(0)->Type) == item->type()) ? static_cast<T>(item) : 0; } Notice the static_cast<T>(0)->Type? I've been using C++ for many years but have never seen 0 being used in a static_cast before. What is this code doing and is it safe? Background: If you derive from QGraphicsItem you are meant to declare an unique enum value called Type that and implement a virtual function called type that returns it, e.g.: class Item : public QGraphicsItem { public: enum { Type = MAGIC_NUMBER }; int type() const { return Type; } ... }; You can then do this: QGraphicsItem* item = new Item; ... Item* derivedItem = qgraphicsitem_cast<Item*>(item); This will probably help explain what that static_cast is trying to do.

    Read the article

  • How can I make PHP scripts timeout gracefully while waiting for long-running MySQL queries?

    - by Mark B
    I have a PHP site which runs quite a lot of database queries. With certain combinations of parameters, these queries can end up running for a long time, triggering an ugly timeout message. I want to replace this with a nice timeout message themed according to the rest of my site style. Anticipating the usual answers to this kind of question: "Optimise your queries so they don't run for so long" - I am logging long-running queries and optimising them, but I only know about these after a user has been affected. "Increase your PHP timeout setting (e.g. set_time_limit, max_execution_time) so that the long-running query can finish" - Sometimes the query can run for several minutes. I want to tell the user there's a problem before that (e.g. after 30 seconds). "Use register_tick_function to monitor how long scripts have been running" - This only gets executed between lines of code in my script. While the script is waiting for a response from the database, the tick function doesn't get called. In case it helps, the site is built using Drupal (with lots of customisation), and is running on a virtual dedicated Linux server on PHP 5.2 with MySQL 5.

    Read the article

  • In Castle Windsor, can I register a Interface component and get a proxy of the implementation?

    - by Thiado de Arruda
    Lets consider some cases: _windsor.Register(Component.For<IProductServices>().ImplementedBy<ProductServices>().Interceptors(typeof(SomeInterceptorType)); In this case, when I ask for a IProductServices windsor will proxy the interface to intercept the interface method calls. If instead I do this : _windsor.Register(Component.For<ProductServices>().Interceptors(typeof(SomeInterceptorType)); then I cant ask for windsor to resolve IProductServices, instead I ask for ProductServices and it will return a dynamic subclass that will intercept virtual method calls. Of course the dynamic subclass still implements 'IProductServices' My question is : Can I register the Interface component like the first case, and get the subclass proxy like in the second case?. There are two reasons for me wanting this: 1 - Because the code that is going to resolve cannot know about the ProductServices class, only about the IProductServices interface. 2 - Because some event invocations that pass the sender as a parameter, will pass the ProductServices object, and in the first case this object is a field on the dynamic proxy, not the real object returned by windsor. Let me give an example of how this can complicate things : Lets say I have a custom collection that does something when their items notify a property change: private void ItemChanged(object sender, PropertyChangedEventArgs e) { int senderIndex = IndexOf(sender); SomeActionOnItemIndex(senderIndex); } This code will fail if I added an interface proxy, because the sender will be the field in the interface proxy and the IndexOf(sender) will return -1.

    Read the article

  • Encode_JSON Errors in Lasso 8.6.2 After Period of Time

    - by ATP_JD
    We are in the process of converting apps from Lasso 8 to Lasso 9, and as an intermediate step, have upgraded from 8.5.5 to 8.6.2 (which runs alongside 9 on our new box, in different virtual hosts). I am finding that with 8.6.2 we are getting a slew of errors on pages that call encode_json. The weird thing with these errors is that they don't start happening until some period of time after the site starts. Then, some hours later, all encode_json calls begin to fail with error messages like this: An error occurred while processing your request. Error Information Error Message: No tag, type or constant was defined under the name "?????????????????" with arguments: array: (pair: (-find)=([\x{0020}-\x{21}\x{23}-\x{5b}\x{5d}-\x{10fff}])), (r) at: onCompare with params: 'r' at: JSON with params: 'reload', -Options=array: (-Internal) at: JSON with params: @map: (reload)=(false), (tcstring)=(LZU), (timestring)=(10:42 AM&nbsp;&nbsp;&nbsp;1442Z) at: [...].lasso with params: 'pageloadtime'='1383038310' on line: 31 at position: 1 Error Code: -9948 (Yes, those Chinese(?) characters are in the error message.) I have removed the 8.5.5 encode_json tag from LassoStartup, so we are using the correct built-in method. The encode_json method fails for any and all parameters I throw at it from simple strings to arrays of maps. Upon restarting the site, encode_json resumes working for an hour or two, seemingly depending on load. On 8.5.5, we don't have this problem. Does anyone have experience with this issue? Any advice regarding trying the 8.5.5 tag swap encode_json to see if I can override the built-in method? Maybe it will work better? Thanks in advance for your time and assistance. -Justin

    Read the article

  • LINQ to SQL Queries odd Materialization

    - by ptoinson
    I ran across an interesting Linq to SQL, uh, feature, the other day. Perhaps someone can give me a logical explanation for the reasoning behind the results. Take the code below as my example which utilizes the AdventureWorks database setup in a Linq to SQL DataContext. This is a clip from my unit test. The resulting customer returned from a call to both CustomerQuery_Test_01() and CustomerQuery_Test_02() is the same. However, the query executed on the SQLServer are different is a major way. The method CustomerQuery_Test_01 us causing the entire Customer table to be materialized, which the call to CustomerQuery_Test_02 is only causing the single customer to be materialized. The resulting SQL Queries are at the bottom of this post. Anyone have a good reason for this? To me, it was highly non-intuitive. protected virtual Customer GetByPrimaryKey(Func<Customer, bool> keySelection) { AdventureWorksDataContext context = new AdventureWorksDataContext(); return (from r in context.Customers select r).SingleOrDefault(keySelection); } [TestMethod] public void CustomerQuery_Test_01() { Customer customer = GetByPrimaryKey(c => c.CustomerID == 2); } [TestMethod] public void CustomerQuery_Test_02() { AdventureWorksDataContext context = new AdventureWorksDataContext(); Customer customer = (from r in context.Customers select r).SingleOrDefault(c => c.CustomerID == 2); } Query for CustomerQuery_Test_01 (notice the lack of a where clause) SELECT [t0].[CustomerID], [t0].[NameStyle], [t0].[Title], [t0].[FirstName], [t0].[MiddleName], [t0].[LastName], [t0].[Suffix], [t0].[CompanyName], [t0].[SalesPerson], [t0].[EmailAddress], [t0].[Phone], [t0].[PasswordHash], [t0].[PasswordSalt], [t0].[rowguid], [t0].[ModifiedDate] FROM [SalesLT].[Customer] AS [t0] Query for CustomerQuery_Test_02 (notice the where clause) SELECT [t0].[CustomerID], [t0].[NameStyle], [t0].[Title], [t0].[FirstName], [t0].[MiddleName], [t0].[LastName], [t0].[Suffix], [t0].[CompanyName], [t0].[SalesPerson], [t0].[EmailAddress], [t0].[Phone], [t0].[PasswordHash], [t0].[PasswordSalt], [t0].[rowguid], [t0].[ModifiedDate] FROM [SalesLT].[Customer] AS [t0] WHERE [t0].[CustomerID] = @p0

    Read the article

  • Resource allocation and automatic deallocation

    - by nabulke
    In my application I got many instances of class CDbaOciNotifier. They all share a pointer to only one instance of class OCIEnv. What I like to achieve is that allocation and deallocation of the resource class OCIEnv will be handled automatically inside class CDbaOciNotifier. The desired behaviour is, with the first instance of class CDbaOciNotifier the environment will be created, after that all following notifiers use that same environment. With the destruction of the last notifier, the environment will be destroyed too (call to custom deleter). What I've got so far (using a static factory method to create notifiers): #pragma once #include <string> #include <memory> #include "boost\noncopyable.hpp" class CDbaOciNotifier : private boost::noncopyable { public: virtual ~CDbaOciNotifier(void); static std::auto_ptr<CDbaOciNotifier> createNotifier(const std::string &tnsName, const std::string &user, const std::string &password); private: CDbaOciNotifier(OCIEnv* envhp); // All notifiers share one environment static OCIEnv* m_ENVHP; // Custom deleter static void freeEnvironment(OCIEnv *env); OCIEnv* m_envhp; }; CPP: #include "DbaOciNotifier.h" using namespace std; OCIEnv* CDbaOciNotifier::m_ENVHP = 0; CDbaOciNotifier::~CDbaOciNotifier(void) { } CDbaOciNotifier::CDbaOciNotifier(OCIEnv* envhp) :m_envhp(envhp) { } void CDbaOciNotifier::freeEnvironment(OCIEnv *env) { OCIHandleFree((dvoid *) env, (ub4) OCI_HTYPE_ENV); *env = null; } auto_ptr<CDbaOciNotifier> CDbaOciNotifier::createNotifier(const string &tnsName, const string &user, const string &password) { if(!m_ENVHP) { OCIEnvCreate( (OCIEnv **) &m_ENVHP, OCI_EVENTS|OCI_OBJECT, (dvoid *)0, (dvoid * (*)(dvoid *, size_t)) 0, (dvoid * (*)(dvoid *, dvoid *, size_t))0, (void (*)(dvoid *, dvoid *)) 0, (size_t) 0, (dvoid **) 0 ); } //shared_ptr<OCIEnv> spEnvhp(m_ENVHP, freeEnvironment); ...got so far... return auto_ptr<CDbaOciNotifier>(new CDbaOciNotifier(m_ENVHP)); } I'd like to avoid counting references (notifiers) myself, and use something like shared_ptr. Do you see an easy solution to my problem?

    Read the article

  • Quantifying the Performance of Garbage Collection vs. Explicit Memory Management

    - by EmbeddedProg
    I found this article here: Quantifying the Performance of Garbage Collection vs. Explicit Memory Management http://www.cs.umass.edu/~emery/pubs/gcvsmalloc.pdf In the conclusion section, it reads: Comparing runtime, space consumption, and virtual memory footprints over a range of benchmarks, we show that the runtime performance of the best-performing garbage collector is competitive with explicit memory management when given enough memory. In particular, when garbage collection has five times as much memory as required, its runtime performance matches or slightly exceeds that of explicit memory management. However, garbage collection’s performance degrades substantially when it must use smaller heaps. With three times as much memory, it runs 17% slower on average, and with twice as much memory, it runs 70% slower. Garbage collection also is more susceptible to paging when physical memory is scarce. In such conditions, all of the garbage collectors we examine here suffer order-of-magnitude performance penalties relative to explicit memory management. So, if my understanding is correct: if I have an app written in native C++ requiring 100 MB of memory, to achieve the same performance with a "managed" (i.e. garbage collector based) language (e.g. Java, C#), the app should require 5*100 MB = 500 MB? (And with 2*100 MB = 200 MB, the managed app would run 70% slower than the native app?) Do you know if current (i.e. latest Java VM's and .NET 4.0's) garbage collectors suffer the same problems described in the aforementioned article? Has the performance of modern garbage collectors improved? Thanks.

    Read the article

  • Looking for a book which teaches how to write applications (as opposed to writng code)

    - by rumtscho
    I am not a developer. I have coded for fun and for university projects in several languages, and during an internship, I have written code which is still in use by a department of Fortune Global 500 company. I also have extensive theoretical knowledge of software engineering - process models, architecture, project management, UI construction using Lauesen's virtual windows... you get the picture. But I am not involved with software development in my job. I recently decided to start coding for fun again, and now I have some free days to do it. But this time, I want to do it right. I want to write a real, useful application, install it on my devices and use it myself. Also I want to publish it for others to use, should they want to do so. I am vaguely aware that there is more to writing an application than to writing code. There is stuff like version control software, decision for the right IDE, having a suite of unit tests, producing an installation package - and probably lots of other things I never thought of but which must be taken care of in a proper application, as opposed to a bunch of classes I am running from my IDE. All this is stuff I should know before I start, but I have not learned it. Coding books touch on some of the subjects like IDE choice, but don't go into detail, and are not exhaustive. Theoretical software engineering textbooks are even less helpful. So is there a book which teaches exactly that? I know that I can find information on each of these topics on the Internet, but I'd rather have a systematic book exhaustively listing all the things I should take care of if I want to create a good application, and offering the currently accepted solutions for them. In the best case, it will be language- and platform independent, but if you know of a good book focusing on a specific platform, I would like to know about it too. I know I want a lot, but given how important such knowledge is and how many people need it, surely somebody must have written such a book?

    Read the article

  • Implementing inotifycollectionchanged interface

    - by George
    Hello, I need to implement a collection with special capabilities. In addition, I want to bind this collection to a ListView, Therefore I ended up with the next code (I omitted some methods to make it shorter here in the forum): public class myCollection<T> : INotifyCollectionChanged { private Collection<T> collection = new Collection<T>(); public event NotifyCollectionChangedEventHandler CollectionChanged; public void Add(T item) { collection.Insert(collection.Count, item); OnCollectionChange(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add, item)); } protected virtual void OnCollectionChange(NotifyCollectionChangedEventArgs e) { if (CollectionChanged != null) CollectionChanged(this, e); } } I wanted to test it with a simple data class: public class Person { public string GivenName { get; set; } public string SurName { get; set; } } So I created an instance of myCollection class as follows: myCollection<Person> _PersonCollection = new myCollection<Person>(); public myCollection<Person> PersonCollection { get { return _PersonCollection; } } The problem is that the ListView does not update when the collection updates although I implemented the INotifyCollectionChanged interface. I know that my binding is fine (in XAML) because when I use the ObservableCollecion class instead of myCollecion class like this: ObservableCollection<Person> _PersonCollection = new ObservableCollection<Person>(); public ObservableCollection<Person> PersonCollection { get { return _PersonCollection; } } the ListView updates What is the problem?

    Read the article

  • Call 32-bit or 64-bit program from bootloader

    - by user1002358
    There seems to be quite a lot of identical information on the Internet about writing the following 3 bootloaders: Infinite loop jmp $ Print a single character Print "Hello World". This is fantastic, and I've gone through these 3 variations with very little trouble. I'd like to write some 32- or 64-bit code in C and compile it, and call that code from the bootloader... basically a bootloader that, for example, sets the computer up to run some simple numerical simulation. I'll start by listing primes, for example, and then maybe some input/output from the user to maybe compute a Fourier transform. I don't know. I haven't found any information on how to do this, but I can already foresee some problems before I even begin. First of all, compiling a C program compiles it into one of several different files, depending on the target. For Windows, it's a PE file. For Linux, it's a .out file. These files are both quite different. In my instance, the target isn't Windows or Linux, it's just whatever I have written in the bootloader. Secondly, where would the actual code reside? The bootloader is exactly 512 bytes, but the program I write in C will certainly compile to something much larger. It will need to sit on my (virtual) hard disk, probably in some sort of file system (which I haven't even defined!) and I will need to load the information from this file into memory before I can even think about executing it. But from my understanding, all this is many, many orders of magnitude more complex than a 12-line "Hello World" bootloader. So my question is: How do I call a large 32- or 64-bit program (written in C/C++) from my 16-bit bootloader.

    Read the article

  • IIS publish of WCF service -- fails with no error message

    - by tavistmorph
    I havea WCF service which I publish from Visual Studio 2008 to an IIS 6. According to the output window of VS, the publish succeeded, no error messages or warnings. When I look at IIS, the virtual directory was created, but there is no .svc listed in the directory. The directory just has my web.config and a bin. Any attempts to call my WCF service fail cause they don't exist. How can I see an error message of what's going wrong? By trial-and-error, I discovered changing my app.config before publishing will make the service show up. Namely my app.config file has these lines: <binding ...> <security mode="Transport"> <transport clientCreditionalType="None"/> </security> </binding> If I switch "Transport" to "None", then my service shows up on IIS. But I do have a certificate installed on IIS on the server, and as far as I can tell, everything is configured correctly on the server. There is no error message in the event log. How can I get a find more error messages about why the service is failing to show up?

    Read the article

  • C# Function Inheritance--Use Child Class Vars with Base Class Function

    - by Sean O'Connor
    Good day, I have a fairly simple question to experienced C# programmers. Basically, I would like to have an abstract base class that contains a function that relies on the values of child classes. I have tried code similar to the following, but the compiler complains that SomeVariable is null when SomeFunction() attempts to use it. Base class: public abstract class BaseClass { protected virtual SomeType SomeVariable; public BaseClass() { this.SomeFunction(); } protected void SomeFunction() { //DO SOMETHING WITH SomeVariable } } A child class: public class ChildClass:BaseClass { protected override SomeType SomeVariable=SomeValue; } Now I would expect that when I do: ChildClass CC=new ChildClass(); A new instance of ChildClass should be made and CC would run its inherited SomeFunction using SomeValue. However, this is not what happens. The compiler complains that SomeVariable is null in BaseClass. Is what I want to do even possible in C#? I have used other managed languages that allow me to do such things, so I certain I am just making a simple mistake here. Any help is greatly appreciated, thank you.

    Read the article

  • java.awt.Desktop.open doesn’t work with PDF files?

    - by Jason S
    It looks like I cannot use Desktop.open() on PDF files regardless of location. Here's a small test program: package com.example.bugs; import java.awt.Desktop; import java.io.File; import java.io.IOException; public class DesktopOpenBug { static public void main(String[] args) { try { Desktop desktop = null; // Before more Desktop API is used, first check // whether the API is supported by this particular // virtual machine (VM) on this particular host. if (Desktop.isDesktopSupported()) { desktop = Desktop.getDesktop(); for (String path : args) { File file = new File(path); System.out.println("Opening "+file); desktop.open(file); } } } catch (IOException e) { e.printStackTrace(); } } } If I run DesktopOpenBug with arguments c:\tmp\zz1.txt c:\tmp\zz.xml c:\tmp\ss.pdf (3 files I happen to have lying around) I get this result: (the .txt and .xml files open up fine) Opening c:\tmp\zz1.txt Opening c:\tmp\zz.xml Opening c:\tmp\ss.pdf java.io.IOException: Failed to open file:/c:/tmp/ss.pdf. Error message: The parameter is incorrect. at sun.awt.windows.WDesktopPeer.ShellExecute(Unknown Source) at sun.awt.windows.WDesktopPeer.open(Unknown Source) at java.awt.Desktop.open(Unknown Source) at com.example.bugs.DesktopOpenBug.main(DesktopOpenBug.java:21) What the heck is going on? I'm running WinXP, I can type "c:\tmp\ss.pdf" at the command prompt and it opens up just fine. edit: if this is an example of Sun Java bug #6764271 please help by voting for it. What a pain. :(

    Read the article

  • Doubt on pointer conversion

    - by Simone
    Suppose we have the following code: #include <iostream> struct A { virtual void f() { std::cout << "A::f()" << std::endl; } }; struct B: A { void f() { std::cout << "B::f()" << std::endl; } }; void to_A(void* voidp) { A* aptr = static_cast<A*>(voidp); aptr->f(); } void to_B(void* voidp) { B* bptr2 = static_cast<B*>(voidp); bptr2->f(); } int main() { B* bptr = new B; void* voidp = bptr; to_A(voidp); // prints B::f() to_B(voidp); // prints B::f() } is this code guaranteed to always work as in the code comments or is it UB? AFAIK it should be ok, but I'd like to be reassured.

    Read the article

< Previous Page | 367 368 369 370 371 372 373 374 375 376 377 378  | Next Page >