<Button MouseLeftButtonDown="Button_MouseLeftButtonDown" MouseMove="Button_MouseMove" MouseLeftButtonUp="Button_MouseLeftButtonUp" Canvas.Left="550" Canvas.Top="50" FontSize="18" Background="Black" Width="160" Height="80" ClickMode="Hover">关于button的ClickMode属性等于Hover,如果忘记设置这个属性，则控件无法拖动