helloapi.c

C#一个实例源代码

#include <windows.h>

LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
                    PSTR szCmdLine, int iCmdShow)
{
     static TCHAR szAppName[] = TEXT ("HelloAPI") ;
     HWND         hwnd ;
     MSG          msg ;
     WNDCLASS     wndclass ;

     wndclass.style         = CS_HREDRAW | CS_VREDRAW|CS_DBLCLKS;
     wndclass.lpfnWndProc   = WndProc ;
     wndclass.cbClsExtra    = 0 ;
     wndclass.cbWndExtra    = 0 ;
     wndclass.hInstance     = hInstance ;
     wndclass.hIcon         = LoadIcon (NULL, IDI_APPLICATION) ;
     wndclass.hCursor       = LoadCursor (NULL, IDC_ARROW) ;
     wndclass.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH) ;
     wndclass.lpszMenuName  = NULL ;
     wndclass.lpszClassName = szAppName ;

     if (!RegisterClass (&wndclass))
     {
          MessageBox (NULL, TEXT ("This program requires Windows NT!"), 
                      szAppName, MB_ICONERROR) ;
          return 0 ;
     }
     
     hwnd = CreateWindow (szAppName,                
                          TEXT ("Hello API!"), 
                          WS_OVERLAPPEDWINDOW
						  |WS_HSCROLL|WS_VSCROLL,       
                          CW_USEDEFAULT,             
                          CW_USEDEFAULT,             
                          CW_USEDEFAULT,             
                          CW_USEDEFAULT,            
                          NULL,                  
                          NULL,                      
                          hInstance,                
                          NULL) ;                  
     
     ShowWindow (hwnd, iCmdShow) ;
     UpdateWindow (hwnd) ;
     
     while (GetMessage (&msg, NULL, 0, 0))
     {
          TranslateMessage (&msg) ;
          DispatchMessage (&msg) ;
     }
     return msg.wParam ;
}

LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
	 HDC         hdc ;
     PAINTSTRUCT ps ;
     RECT        rect ;
         
     switch (message)
     {
	 case WM_PAINT:
          hdc = BeginPaint (hwnd, &ps) ;
          GetClientRect (hwnd, &rect) ;
          DrawText (hdc, TEXT ("Hello API"), -1, &rect,
                    DT_SINGLELINE | DT_CENTER | DT_VCENTER) ;
          EndPaint (hwnd, &ps) ;
          return 0 ;
              
     case WM_DESTROY:
          PostQuitMessage (0) ;
          return 0 ;
     }
     return DefWindowProc (hwnd, message, wParam, lParam) ;
}