控件拖动问题.有代码.请帮我看看.....

lelediyi

控件初始位置(0,0):无法移动到最右边及右下角.不知道如何处理?请帮我看看.可能代码哪里有问题.我也找不出来.请大家帮我看看啊,困扰了好久
D3DXVECTOR2& GetAbsolutePosition(D3DXVECTOR2& Position)
{
Position.x += Left;
Position.y += Top;
return Position;
}

bool onMouseMove(int KeyState, POINT pt)
{  
//响应鼠标移动消息
D3DXVECTOR2 Abs;
Abs.x = 0;
Abs.y = 0;
GetAbsolutePosition(Abs);
pos.x = Left + (pt.x - LastPoint.x) - Abs.x;
pos.y = Top  + (pt.y - LastPoint.y) - Abs.y;
return true;
}
bool OnLButtonDown(int KeyState, POINT pt)
{
//相应鼠标左键按下消息

LastPoint.x = pt.x;
LastPoint.y = pt.y;
return true;
}