VC++ 获取鼠标状态,获取鼠标弹起消息

LRESULT CALLBACK TestProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    switch (msg)
    {
    case WM_LBUTTONDOWN: //左键按下
        {
            SetCapture(hwnd);
        }
        break;
    case WM_MOUSEMOVE: //鼠标按下移动
        {
                if(GetCapture() ==  hwnd)
                {
                   //鼠标按下并移动...
                }
        }
        break;
    case WM_LBUTTONUP: //左键弹起
        {
            if(GetCapture()  ==  hwnd)
                ReleaseCapture(); //当前线程中的窗口释放鼠标捕获，并恢复通常的鼠标输入处理。
        }
        break;

        return 0;
    }

}