#include <windows.h>

#define ID_TIME                1

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

int WINAPI WinMain (HINSTANCE hInstance,
                    HINSTANCE hPrevInstance,
                    LPSTR lpCmdLine,
                    int iCmdShow)
{
    TCHAR                    Title[] = "按下鼠标左键进行绘图,按下右键清屏";
    TCHAR                    ClsName[] = "szCls";
    HWND                    hwnd;
    WNDCLASS                wc;
    MSG                        msg;

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

    if ( !RegisterClass (&wc) )
    {
        MessageBox (NULL, TEXT ("RegisterError"), TEXT ("ERROR"), MB_OK | MB_ICONINFORMATION);
        return -1;
    }
    hwnd = CreateWindow (
        ClsName, Title,
        WS_OVERLAPPEDWINDOW,
        CW_USEDEFAULT, CW_USEDEFAULT,
        CW_USEDEFAULT, CW_USEDEFAULT,
        NULL, NULL, hInstance, NULL);
    ShowWindow (hwnd, SW_SHOW);

    while ( GetMessage (&msg, NULL, 0, 0) > 0 )
    {
        TranslateMessage (&msg);
        DispatchMessage (&msg);
    }
    return msg.wParam;
}

LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    HDC                    hdc;
    static int            cur_x, cur_y;
    switch (message)
    {
    case WM_CREATE:
        {
        }
        break;
    case WM_MOUSEMOVE:
        {
            cur_x = (int) LOWORD(lParam);
            cur_y = (int) HIWORD(lParam);
        }
        break;
    case WM_LBUTTONDOWN:
        {
            SetTimer (hwnd, ID_TIME, 1, NULL);
        }
        break;
    case WM_LBUTTONUP:
        {
            KillTimer (hwnd, ID_TIME);
        }
        break;
    case WM_TIMER:
        {
            hdc = GetDC (hwnd);
           
            SetPixel (hdc, cur_x, cur_y, RGB (255, 0, 0));

            ReleaseDC (hwnd, hdc);
        }
        break;
    case WM_RBUTTONDOWN:
        {
            InvalidateRect (hwnd, NULL, TRUE);
        }
        break;
    case WM_CLOSE:
        {
            PostQuitMessage (0);
        }
        break;
    default:
        return DefWindowProc (hwnd, message, wParam, lParam);
    }
    return 0;
}

很菜鸟,贴出来记录下自己学习的脚步

那个程序着实存在很多问题,因为每次发生重绘的时候并没有保存之前的图形，所以就像你说的那样留空了…那时候写这个程序还并不知道怎么解决这个问题，不过若现在要我重写的话，我会用上内存dc缓冲…
现在来看这个帖子，还真有点兴奋，因为俺发现比以前进步啦，啊哈哈哈哈～飘过