wmain - Developer IT

What is the difference between wmain and main?

- by Ole Jak

So I have some class starting with #include <wchar.h> #include <stdlib.h> ant there is that function wmain. What is it different from main function i usualy use in my C classes?

Can we use wmain() functions with Unix compilers or it'll work only on windows?

- by Ole Jak

Can we use wmain() functions with Unix compilers (git) or it'll work only on\for windows?

Why only the constant expression can be used as case expression in Switch statement?

Hi, what is bothering me is that I can't found an info regarding the question from the title. I found that assembly form the Switch-case statement is compiled into bunch of (MS VC 2008 compiler) cmp and je calls: 0041250C mov eax,dword ptr [i] 0041250F mov dword ptr [ebp-100h],eax 00412515 cmp dword ptr [ebp-100h],1 0041251C je wmain+52h (412532h) 0041251E cmp dword ptr [ebp-100h],2 00412525 je wmain+5Bh (41253Bh) 00412527 cmp dword ptr [ebp-100h],3 0041252E je wmain+64h (412544h) 00412530 jmp wmain+6Bh (41254Bh) where for above code will in case that if condition (i) is equal to 2, jump to address 41253Bh and do execution form there (at 41253Bh starts the code for 'case 2:' block) What I don't understand is why in case that,for instance, function is used as 'case expression', why first function couldn't be evaluated and then its result compared with the condition? Am I missing something? Thank you in advance

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How do I define a template class and divide it into multiple files?

- by hkBattousai

I have written a simple template class for test purpose. It compiles without any errors, but when I try to use it in main(), it give some linker errors. main.cpp #include <iostream> #include "MyNumber.h" int wmain(int argc, wchar_t * argv[]) { MyNumber<float> num; num.SetValue(3.14); std::cout << "My number is " << num.GetValue() << "." << std::endl; system("pause"); return 0; } MyNumber.h #pragma once template <class T> class MyNumber { public: MyNumber(); ~MyNumber(); void SetValue(T val); T GetValue(); private: T m_Number; }; MyNumber.cpp #include "MyNumber.h" template <class T> MyNumber<T>::MyNumber() { m_Number = static_cast<T>(0); } template <class T> MyNumber<T>::~MyNumber() { } template <class T> void MyNumber<T>::SetValue(T val) { m_Number = val; } template <class T> T MyNumber<T>::GetValue() { return m_Number; } When I build this code, I get the following linker errors: Error 7 Console Demo C:\Development\IDE\Visual Studio 2010\SAVE\Grand Solution\X64\Debug\Console Demo.exe 1 error LNK1120: 4 unresolved externals Error 3 Console Demo C:\Development\IDE\Visual Studio 2010\SAVE\Grand Solution\Console Demo\main.obj error LNK2019: unresolved external symbol "public: __cdecl MyNumber::~MyNumber(void)" (??1?$MyNumber@M@@QEAA@XZ) referenced in function wmain Error 6 Console Demo C:\Development\IDE\Visual Studio 2010\SAVE\Grand Solution\Console Demo\main.obj error LNK2019: unresolved external symbol "public: __cdecl MyNumber::MyNumber(void)" (??0?$MyNumber@M@@QEAA@XZ) referenced in function wmain Error 4 Console Demo C:\Development\IDE\Visual Studio 2010\SAVE\Grand Solution\Console Demo\main.obj error LNK2019: unresolved external symbol "public: float __cdecl MyNumber::GetValue(void)" (?GetValue@?$MyNumber@M@@QEAAMXZ) referenced in function wmain Error 5 Console Demo C:\Development\IDE\Visual Studio 2010\SAVE\Grand Solution\Console Demo\main.obj error LNK2019: unresolved external symbol "public: void __cdecl MyNumber::SetValue(float)" (?SetValue@?$MyNumber@M@@QEAAXM@Z) referenced in function wmain But, if I leave main() empty, I don't get any linker errors. What is wrong with my template class? What am I doing wrong?

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wpf exit thread automatically when application closes

- by toni

Hi, I have a main wpf window and one of its controls is a user control that I have created. this user control is an analog clock and contains a thread that update hour, minute and second hands. Initially it wasn't a thread, it was a timer event that updated the hour, minutes and seconds but I have changed it to a thread because the application do some hard work when the user press a start button and then the clock don't update so I changed it to a thread. COde snippet of wpf window: <Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:local="clr-namespace:GParts" xmlns:Microsoft_Windows_Themes="clr-namespace:Microsoft.Windows.Themes assembly=PresentationFramework.Aero" xmlns:UC="clr-namespace:GParts.UserControls" x:Class="GParts.WinMain" Title="GParts" WindowState="Maximized" Closing="Window_Closing" Icon="/Resources/Calendar-clock.png" x:Name="WMain" > <...>  <UC:AnalogClock Grid.Row="1" x:Name="AnalogClock" Background="Transparent" Margin="0" Height="Auto" Width="Auto"/> <...> </Window> My problem is when the user exits the application then the thread seems to continue executing. I would like the thread finishes automatically when main windows closes. code snippet of user control constructor: namespace GParts.UserControls { /// <summary> /// Lógica de interacción para AnalogClock.xaml /// </summary> public partial class AnalogClock : UserControl { System.Timers.Timer timer = new System.Timers.Timer(1000); public AnalogClock() { InitializeComponent(); MDCalendar mdCalendar = new MDCalendar(); DateTime date = DateTime.Now; TimeZone time = TimeZone.CurrentTimeZone; TimeSpan difference = time.GetUtcOffset(date); uint currentTime = mdCalendar.Time() + (uint)difference.TotalSeconds; christianityCalendar.Content = mdCalendar.Date("d/e/Z", currentTime, false); // this was before implementing thread //timer.Elapsed += new System.Timers.ElapsedEventHandler(timer_Elapsed); //timer.Enabled = true; // The Work to perform ThreadStart start = delegate() { // With this condition the thread exits when main window closes but // despite of this it seems like the thread continues executing after // exiting application because in task manager cpu is very busy // while ((this.IsInitialized) && (this.Dispatcher.HasShutdownFinished== false)) { this.Dispatcher.Invoke(DispatcherPriority.Normal, (Action)(() => { DateTime hora = DateTime.Now; secondHand.Angle = hora.Second * 6; minuteHand.Angle = hora.Minute * 6; hourHand.Angle = (hora.Hour * 30) + (hora.Minute * 0.5); DigitalClock.CurrentTime = hora; })); } Console.Write("Quit ok"); }; // Create the thread and kick it started! new Thread(start).Start(); } // this was before implementing thread void timer_Elapsed(object sender, System.Timers.ElapsedEventArgs e) { this.Dispatcher.Invoke(DispatcherPriority.Normal, (Action)(() => { DateTime hora = DateTime.Now; secondHand.Angle = hora.Second * 6; minuteHand.Angle = hora.Minute * 6; hourHand.Angle = (hora.Hour * 30) + (hora.Minute * 0.5); DigitalClock.CurrentTime = hora; })); } } // end class } // end namespace How can I exit correctly from thread automatically when main window closes and then application exits? Thanks very much!

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