《windows程序设计》学习_3.2：左键的使用

#include<windows.h>
#include "resource.h"

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

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstace, PSTR szCmdLine, int iCmdShow)
{
    static TCHAR szAppName[] = TEXT ("Stick1");
    HWND        hwnd;
    MSG         msg;
    WNDCLASS    wndclass;

    wndclass.style                  = CS_HREDRAW | CS_VREDRAW ;
    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 ("The Program requires Windows NT!"), szAppName, MB_ICONERROR);
        return 0;
    }

    hwnd = CreateWindow (szAppName,
                        TEXT ("Stick 1"),
                        WS_OVERLAPPEDWINDOW,
                        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)
{
    static HBITMAP hBitmap;
    static int     cxClient, cyClient, cxSource, cySource;
    BITMAP         bitmap;
    HDC            hdc,hdcMem;
    HINSTANCE      hInstance;
    int            x,y;
//    PAINTSTRUCT    ps;


    switch(message)
    {
    case WM_CREATE:
        hInstance = ((LPCREATESTRUCT) lParam) ->hInstance;

        hBitmap = LoadBitmap(hInstance,MAKEINTRESOURCE(IDM_BITMAP)/*TEXT("bitmap1")*/);
        GetObject(hBitmap,sizeof(BITMAP),&bitmap);

        cxSource = bitmap.bmWidth;
        cySource = bitmap.bmHeight;

        return 0;

    case WM_LBUTTONDOWN:
        hdc = GetDC(hwnd);

        hdcMem = CreateCompatibleDC(hdc);
        SelectObject(hdcMem, hBitmap);

        x = LOWORD(lParam);
        y = HIWORD(lParam);

        BitBlt(hdc, x, y, cxSource, cySource, hdcMem, 0, 0, SRCCOPY);

        DeleteDC(hdcMem);
        ReleaseDC(hwnd, hdc);
        return 0;
    case WM_DESTROY:
        DeleteObject(hBitmap);
        PostQuitMessage(0);
        return 0;
    }
    return DefWindowProc(hwnd, message, wParam, lParam);
}