[转]WPF——Thumb

Thumb类，表示可由用户拖动的控件。其主要三个事件分别DragDelta,DragStarted,DragCompleted.

DragDelta——当 Thumb 控件具有逻辑焦点和鼠标捕获时，随着鼠标位置更改发生一次或多次。

DragStarted——在 Thumb 控件接收逻辑焦点和鼠标捕获时发生。

DragCompleted——在 Thumb 控件失去鼠标捕获时发生。

 1  <Window.Resources> 2     <ResourceDictionary> 3       <ControlTemplate x:Key="template1"> 4                 <Ellipse Width="60" Height="30"> 5                     <Ellipse.Fill> 6                         <SolidColorBrush Color="Black"></SolidColorBrush> 7                     </Ellipse.Fill> 8                 </Ellipse> 9             </ControlTemplate>10     </ResourceDictionary>11   </Window.Resources>12   13   <Canvas Name="myCanvas">14     <Thumb Name="myThumb" DragDelta="onDragDelta" Background="Blue"  DragStarted="myThumb_DragStarted" DragCompleted="myThumb_DragCompleted"15            Canvas.Left="0" Canvas.Top="0"  Width="200" Height="200"/>16 17         <!--Template="{StaticResource template1}",若此处采用此种方法为Thumb绑定模版，是无法通过DragStarted,DragCompleted事件来改变其背景的-->18     </Canvas>

 1    void onDragDelta(object sender, DragDeltaEventArgs e) 2         { 3             Canvas.SetLeft(myThumb, Canvas.GetLeft(myThumb) + e.HorizontalChange); 4                                         5             Canvas.SetTop(myThumb, Canvas.GetTop(myThumb) +  e.VerticalChange); 6                                        7         } 8  9         private void myThumb_DragStarted(object sender, DragStartedEventArgs e)10         {11             myThumb.Background = Brushes.Orange;12         }13 14         private void myThumb_DragCompleted(object sender, DragCompletedEventArgs e)15         {16             myThumb.Background = Brushes.Blue;17         }