因为钟爱这个板块，所以就在此提问了

[erwinrommel]

我现在想画图，但是每次画图后，在窗口重绘时所绘制的图案总会消失，我想用CreateCompatibleDC补救，但是似乎不行，源代码如下：望高人指点迷津！

int wmId, wmEvent;
PAINTSTRUCT ps;
HDC hdc;
static HDC chdc;

case WM_MOUSEMOVE: // 移动鼠标
{
hdc = GetDC( hWnd );
chdc = CreateCompatibleDC( hdc );
ptEnd.x = LOWORD (lParam) ;
ptEnd.y = HIWORD (lParam) ;
MoveToEx ( chdc, ptBeg.x, ptBeg.y, NULL );
LineTo( chdc, ptEnd.x, ptEnd.y );
MoveToEx ( hdc, ptBeg.x, ptBeg.y, NULL );
LineTo( hdc, ptEnd.x, ptEnd.y );
ptBeg.x = ptEnd.x;
ptBeg.y = ptEnd.y;
break;
}
case WM_PAINT:
{
hdc = BeginPaint(hWnd, &ps);
::BitBlt( hdc, 10*cxChar, 0, rect.right-10*cxChar,rect.bottom, chdc, 0,0, MERGECOPY );
EndPaint(hWnd, &ps);
break;
}

[xkou]

WM_MOUSEMOVE :只处理会图参数
WM_PAINT: 处理LineTO..,

[yjh1982]

钟爱它就不要.....

[qiuafa]

捧场！

[niky8053]

在WM_MOUSEMOVE:消息中加入
InvalidateRect(hwnd,NULL,FALSE);
看看这样行不行？