#include 
     
      LRESULT CALLBACK WndProc(HWND hwnd, UINT Message, WPARAM wParam, LPARAM lParam) {    static int  cxClient, cyClient, draw=0, started=0, LineWide=0, R=0, G=0, B=0;    static HPEN hPen;    static HDC         hdc ;    int         i ;    static PAINTSTRUCT ps ;    switch(Message) {        case WM_SIZE: {            cxClient = LOWORD (lParam) ;            cyClient = HIWORD (lParam) ;            break;        }        case WM_LBUTTONDOWN:            draw = 1;             if (!started) {                hdc = BeginPaint (hwnd, &ps) ;            }            started = 1;             MoveToEx (hdc, LOWORD(lParam), HIWORD(lParam), NULL) ;            break;         case WM_LBUTTONUP:            draw = 0;             break;         case WM_MOUSEMOVE:            if (draw) {                hPen = CreatePen(PS_SOLID, LineWide, RGB(R,G,B));                SelectObject(hdc, hPen);                LineTo(hdc, LOWORD(lParam), HIWORD(lParam)) ;            }            break;         case WM_KEYDOWN:            switch(wParam){                case VK_UP: if (LineWide<20) LineWide++; break;                case VK_DOWN: if (LineWide>0) LineWide--; break;                case VK_LEFT: if (R<255) R++; if (G<255) G++; if (B<255) B++; break;                case VK_RIGHT: if (R>0) R--; if (G>0) G--; if (B>0) B--; break;                case 'R': case 'r':    if (R<255) R++; else {
   if(G>0)G--;if(B>0)B--;}; break;                 case 'G': case 'g':    if (G<255) G++; else {
   if(R>0)R--;if(B>0)B--;}; break;                 case 'B': case 'b':    if (B<255) B++; else {
   if(R>0)R--;if(G>0)G--;}; break;             }            break;        case WM_PAINT: {            break;        }        case WM_CLOSE: {            DestroyWindow(hwnd);            break;        }        case WM_DESTROY: {            PostQuitMessage(0);            break;        }        default:            return DefWindowProc(hwnd, Message, wParam, lParam);    }    return 0;}int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow) {    WNDCLASSEX wc;    HWND hwnd;    MSG Msg;    memset(&wc,0,sizeof(wc));    wc.cbSize         = sizeof(WNDCLASSEX);    wc.lpfnWndProc     = WndProc; /* This is where we will send messages to */    wc.hInstance     = hInstance;    wc.hCursor         = LoadCursor(NULL, IDC_ARROW);    wc.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);    wc.lpszClassName = "WindowClass";    wc.hIcon         = LoadIcon(NULL, IDI_APPLICATION); /* Load a standard icon */    wc.hIconSm         = LoadIcon(NULL, IDI_APPLICATION);    if(!RegisterClassEx(&wc)) {        MessageBox(NULL, "Window Registration Failed!","Error!",MB_ICONEXCLAMATION|MB_OK);        return 0;    }    hwnd = CreateWindowEx(WS_EX_CLIENTEDGE,"WindowClass","涂鸦板",WS_VISIBLE|WS_OVERLAPPEDWINDOW,        CW_USEDEFAULT, CW_USEDEFAULT, 640, 480, NULL, NULL, hInstance, NULL);    if(hwnd == NULL) {        MessageBox(NULL, "Window Creation Failed!","Error!",MB_ICONEXCLAMATION|MB_OK);        return 0;    }    while(GetMessage(&Msg, NULL, 0, 0) > 0) {        TranslateMessage(&Msg);        DispatchMessage(&Msg);    }    return Msg.wParam;}