通过ControlTemplate自定义控件的外观和行为

    在WPF中，每个可视化控件都有一个默认的模板，通过替换这个默认的模板，可以实现自定义的控件外观和行为。例如：ButtonTemplate 是自定义模板，经过button1.Template = ButtonTemplate以后button1的外观就是自定义外观，button1的行为也由ButtonTemplate决定。一个自定义模板由3个部分组成：资源、控件外观、触发器。

我们通过一个例子来学习自定义控件。做成以后的图片：

以下代码就是一个自定义模板的基本框架，虽然什么也不能做，但是可以编译通过了。

<Window.Resources>

        <!-- Button模板 -->

        <ControlTemplatex:Key="ButtonTemplate"TargetType="Button">

                <!--资源 -->

                <ControlTemplate.Resources>

                </ControlTemplate.Resources>

                <!--控件外观-->

                <!--触发器 -->

                <ControlTemplate.Triggers>

                </ControlTemplate.Triggers>

                </ControlTemplate>

</Window.Resources>

<ButtonName="buttonDemo"Template="{StaticResource ButtonTemplate}"></Button>

我们来增加一点点东西。 

<Button Name="buttonDemo"
      Template="{StaticResource ButtonTemplate}"
      Margin="12,12,12,12"
      Content ="Hello World"
      Width="180"
      Height ="72"
      Foreground ="Black"
      FontSize="24"
      FontStyle="Italic"
      FontWeight="Bold"
      HorizontalContentAlignment ="Center"
      VerticalContentAlignment ="Center">  
 </Button>

然后开始修改自定义模板：

<Window.Resources>
  <!-- Button模板 -->
  <ControlTemplate x:Key="ButtonTemplate" TargetType="Button">
   <!-- 资源 -->
   <ControlTemplate.Resources>
    <!-- Button表面的渐变 -->
    <LinearGradientBrush x:Key="ButtonShapeGradientBrush" StartPoint ="0,0" EndPoint ="0,1">
     <GradientStop Color="#FF555555" Offset="0.0" />
     <GradientStop Color="#FF999999" Offset="0.2" />
     <GradientStop Color="#FFEEEEEE" Offset="0.5" />
     <GradientStop Color="#FF999999" Offset="0.8" />
     <GradientStop Color="#FF555555" Offset="1.0" />
    </LinearGradientBrush>
    <!-- 鼠标单击的动画 -->
    <Storyboard x:Key="MouseClickStoryboard">
     <DoubleAnimationUsingKeyFrames Storyboard.TargetName="buttonShape" Storyboard.TargetProperty="RadiusX" BeginTime="00:00:00">
      <SplineDoubleKeyFrame KeyTime ="00:00:00" Value="40" />
      <SplineDoubleKeyFrame KeyTime ="00:00:00.50" Value="64" />
      <SplineDoubleKeyFrame KeyTime ="00:00:01" Value="40" />      
     </DoubleAnimationUsingKeyFrames>
     <DoubleAnimationUsingKeyFrames Storyboard.TargetName="buttonShape" Storyboard.TargetProperty="RadiusY" BeginTime="00:00:00">
      <SplineDoubleKeyFrame KeyTime ="00:00:00" Value="40" />
      <SplineDoubleKeyFrame KeyTime ="00:00:00.50" Value="64" />
      <SplineDoubleKeyFrame KeyTime ="00:00:01" Value="40" />
     </DoubleAnimationUsingKeyFrames>
    </Storyboard>
   </ControlTemplate.Resources>
   <!-- 控件外观 -->
   <Grid>
    <Rectangle Name="buttonShape"
               Width="{TemplateBinding Button.Width}"
               Height="{TemplateBinding Button.Height}"
               RadiusX ="40"
               RadiusY ="40"
               Stroke="Black"
               StrokeThickness="2"
               Fill="{StaticResource ButtonShapeGradientBrush}">
    </Rectangle>
    <ContentPresenter Name="content"
                      Content="{TemplateBinding Content}"
                      ContentTemplate="{TemplateBinding ContentTemplate}"
                      Margin="{TemplateBinding Padding}"
                      TextElement.Foreground ="{TemplateBinding Foreground}"
                      TextElement.FontSize="{TemplateBinding FontSize}"
                      TextElement.FontStyle="{TemplateBinding FontStyle}"
                      TextElement.FontWeight ="{TemplateBinding FontWeight}"
                      HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
                      VerticalAlignment="{TemplateBinding VerticalContentAlignment}">
    </ContentPresenter>
   </Grid>   
   <!-- 触发器 -->
   <ControlTemplate.Triggers>
    <Trigger Property="IsMouseOver" Value="true">
     <Setter TargetName="content" Property="TextElement.Foreground" Value="#FFFF0000" />
     <Setter TargetName="buttonShape" Property="Stroke" Value="#FFFF0000" />
    </Trigger>
    <EventTrigger RoutedEvent="Mouse.MouseDown" SourceName="buttonShape">
     <EventTrigger.Actions>
      <BeginStoryboard Storyboard="{StaticResource MouseClickStoryboard}" />
     </EventTrigger.Actions>
    </EventTrigger>
    <EventTrigger RoutedEvent="Mouse.MouseDown" SourceName="content">
     <EventTrigger.Actions>
      <BeginStoryboard Storyboard="{StaticResource MouseClickStoryboard}" />
     </EventTrigger.Actions>
    </EventTrigger>    
   </ControlTemplate.Triggers>
  </ControlTemplate>
 </Window.Resources>
 <Button Name="buttonDemo"
      Template="{StaticResource ButtonTemplate}"
      Margin="12,12,12,12"
      Content ="Hello World"
      Width="180"
      Height ="72"
      Foreground ="Black"
      FontSize="24"
      FontStyle="Italic"
      FontWeight="Bold"
      HorizontalContentAlignment ="Center"
      VerticalContentAlignment ="Center">  
 </Button>

代码简单，没什么好说的啊！