0: Basic Win32 Startup/Shutdown

 

The first thing to begin with, is showing a window. First, you need to include the necessary header files. We use the #define to tell the Windows headers we are a simple win32 app, and not include any MFC stuff:

 

#define WIN32_MEAN_AND_LEAN

#include <windows.h>

#include <windowsx.h>

 

Now we define some global tags/constants, like the window class string(used for identifying this window), its title(caption) and size(in pixels):

 

#define WINDOWS_CLASS "Tutorial0WindowClass"

#define WINDOWS_CAPTION "Tutorial #0"

const int SCREEN_X = 640;

const int SCREEN_Y = 480;

 

Now we define the window procedure. Windows passes messages to our app by using this function, and it is the ‘heart’ of any windows application. This must be implemented in order to behave correctly within the Windows OS, and to ‘gracefully’ finish:

 

LRESULT WINAPI MsgProc( HWND hwnd, UINT msg, WPARAM wparam, LPARAM lparam )

{

    switch( msg )

    {

            case WM_PAINT:

                  {

                        // Simply clear the window to white, and display a message centered

                        RECT rect;

                        PAINTSTRUCT ps;

                        HDC hdc = BeginPaint( hwnd, &ps );

                        GetClientRect( hwnd, &rect );

                        FillRect( hdc, &rect, CreateSolidBrush( 0x00ffffff ) );

                        SetTextColor( hdc, 0 );

                        ::DrawText( hdc, "Basic Window", -1, &rect, DT_CENTER | DT_VCENTER | DT_SINGLELINE );

                        EndPaint( hwnd, &ps );

                        return 0;

                  }

 

            case WM_DESTROY:

                  {

                        PostQuitMessage( 0 );

                        return 0;

                  }

    }

 

    return DefWindowProc( hwnd, msg, wparam, lparam );

}

 

Finally, the entry point for the application. This is the same as a ‘main’ in a general C application. This is called first by windows when launching the executable. Then, by registering the window class, we set the above window procedure as the function that will be called by Windows. Then we create a window, and that starts calling the window procedure. We finish with loop that processes any messages sent from Windows to the application. Lastly, we unregister the window class:

 

// Main Win32 Entry Point

int WINAPI WinMain( HINSTANCE hInst, HINSTANCE, LPSTR, INT )

{

      // Register the window class

      WNDCLASSEX wc = { sizeof( WNDCLASSEX ), CS_OWNDC, MsgProc, 0, 0, GetModuleHandle( NULL ), NULL, NULL,

                                    NULL, NULL, WINDOWS_CLASS, NULL };

      RegisterClassEx( &wc );

 

      // Create the application's window

      HWND hWnd = CreateWindow( WINDOWS_CLASS, WINDOWS_CAPTION, WS_CAPTION | WS_POPUPWINDOW | WS_VISIBLE |

S_CLIPSIBLINGS | WS_CLIPCHILDREN, CW_USEDEFAULT, CW_USEDEFAULT, SCREEN_X, SCREEN_Y,

GetDesktopWindow(), NULL, wc.hInstance, NULL );

 

      // Show the window

      ShowWindow( hWnd, SW_SHOWDEFAULT );

      UpdateWindow( hWnd );

 

      // Enter the message loop

      MSG msg;

      ZeroMemory( &msg, sizeof( msg ) );

 

      // Process all messages

      while( msg.message != WM_QUIT )

      {

            if( PeekMessage( &msg, NULL, 0U, 0U, PM_REMOVE ) )

            {

                  TranslateMessage( &msg );

                  DispatchMessage( &msg );

            }

      }

 

      // Unregister the class

      UnregisterClass( WINDOWS_CLASS, wc.hInstance );

 

      return 0;

}

 

Here are the links to the source and the executable.