程序代码：

#include <windows.h>
#pragma comment(linker, "/subsystem:windows")

LRESULT CALLBACK WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    static int iScrWidth, iScrHeight;
    static HDC hScrDC;
    static HDC hSaveDC;
    static HBITMAP hSaveBmp;
    static BOOL bIsDraw;
    static HPEN hPen;

    switch(uMsg)
    {
    case WM_CREATE:
        MessageBox(hWnd, TEXT("按下鼠标中间退出程序"), TEXT("提示"), MB_OK | MB_ICONINFORMATION);
        iScrWidth = GetSystemMetrics(SM_CXSCREEN);
        iScrHeight = GetSystemMetrics(SM_CYSCREEN);
        hScrDC = CreateDC("DISPLAY", NULL, NULL, NULL);
        hSaveDC = CreateCompatibleDC(hScrDC);
        hSaveBmp = CreateCompatibleBitmap(hScrDC, iScrWidth, iScrHeight);
        SelectObject(hSaveDC, hSaveBmp);
        BitBlt(hSaveDC, 0, 0, iScrWidth, iScrHeight, hScrDC, 0, 0, SRCCOPY);
        bIsDraw = FALSE;
        hPen = CreatePen(PS_SOLID, 3, RGB(255, 0, 0));
        SelectObject(hScrDC, hPen);
        SetTimer(hWnd, 1, 10, NULL);
        break;
    case WM_TIMER:
        KillTimer(hWnd, 1);
        BitBlt(hScrDC, 0, 0, iScrWidth, iScrHeight, hSaveDC, 0, 0, SRCCOPY);
        break;
    case WM_MOUSEMOVE:
        if(bIsDraw)
            LineTo(hScrDC, LOWORD(lParam), HIWORD(lParam));
        else
            MoveToEx(hScrDC, LOWORD(lParam), HIWORD(lParam), NULL);
        break;
    case WM_RBUTTONDOWN:
        BitBlt(hScrDC, 0, 0, iScrWidth, iScrHeight, hSaveDC, 0, 0, SRCCOPY);
        break;
    case WM_LBUTTONUP:
        bIsDraw = FALSE;
        break;
    case WM_LBUTTONDOWN:
        bIsDraw = TRUE;
        break;
    case WM_MBUTTONDOWN:
        SendMessage(hWnd, WM_CLOSE, 0, 0);
        break;
    case WM_DESTROY:
        DeleteObject(hSaveBmp);
        DeleteDC(hSaveDC);
        DeleteDC(hScrDC);
        InvalidateRect(NULL, NULL, TRUE);
        PostQuitMessage(0);
        break;
    default:
        return DefWindowProc(hWnd, uMsg, wParam, lParam);
    }
    return 0;
}

int Run(HINSTANCE hInstance)
{
    WNDCLASSEX                wex;
    ZeroMemory(&wex, sizeof(WNDCLASSEX));
    wex.cbSize            =    sizeof(WNDCLASSEX);
    wex.hbrBackground    =    (HBRUSH)GetStockObject(BLACK_BRUSH);
    wex.hCursor            =    LoadCursor(hInstance, IDC_ARROW);
    wex.hIcon            =    LoadIcon(hInstance, IDI_APPLICATION);
    wex.hIconSm            =    LoadIcon(hInstance, IDI_APPLICATION);
    wex.hInstance        =    hInstance;
    wex.lpfnWndProc        =    WndProc;
    wex.lpszClassName    =    TEXT("WndDesktopPen");
    wex.style            =    CS_HREDRAW | CS_VREDRAW;
   
    if( !RegisterClassEx(&wex) )
    {
        MessageBox(NULL, TEXT("RegisterClassEx Error"), TEXT("Error"), MB_OK | MB_ICONINFORMATION);
        return -1;
    }
   
    HWND hWnd = CreateWindowEx(NULL, TEXT("WndDesktopPen"), TEXT(""), WS_DLGFRAME | WS_THICKFRAME | WS_POPUP | WS_VISIBLE, 0, 0, 100, 100, NULL, NULL, hInstance, NULL);
    if(NULL == hWnd)
    {
        MessageBox(NULL, TEXT("CreateWindowEx Error"), TEXT("Error"), MB_OK | MB_ICONINFORMATION);
        return -2;
    }
    ShowWindow(hWnd, SW_MAXIMIZE);
    UpdateWindow(hWnd);
   
    MSG msg;
   
    while( GetMessage(&msg, NULL, 0, 0) > 0 )
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return msg.wParam;
}

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int iCmdShow)
{
    return Run(hInstance);
}

DesktopPen.7z.rar (11.08 KB)