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         }