Question

我找到解决方案Setter.TargetName does not work against an element from the BasedOn setting。但我不明白他是如何向我起诉的。我有一节课：

public class MyCheckBox: CheckBox
{
  public bool DefaultValue
  {
    get { return (bool)GetValue(DefaultValueProperty); }
    set { SetValue(DefaultValueProperty, value); }
  }
  public static readonly DependencyProperty DefaultValueProperty =
      DependencyProperty.Register("DefaultValue", typeof(bool), typeof(MyCheckBox), new UIPropertyMetadata(false));


  protected override void OnToggle()
  {
    this.IsChecked = this.IsChecked == null ? !DefaultValue : this.IsChecked.Value ? false : true;
  }
}

和XAML

<Style TargetType="{x:Type CheckBox}">
  <Style.Resources>
    <Imaging:BitmapImage x:Key="CheckBoxStatusSource" UriSource="FalseIfNull.png"/> <!-- icon if [IsChecked] is [null] -->
  </Style.Resources>
  <Setter Property="Template">
    <Setter.Value>
      <ControlTemplate TargetType="{x:Type CheckBox}">
        <Image x:Name="CheckBoxStatus" Source="{DynamicResource CheckBoxStatusSource}"/>
        <ControlTemplate.Triggers>
          <Trigger Property="IsChecked" Value="True">
            <Setter TargetName="CheckBoxStatus" Property="Source" Value="b.png"/><!-- icon if [IsChecked] is [true] -->
          </Trigger>
          <Trigger Property="IsChecked" Value="False">
            <Setter TargetName="CheckBoxStatus" Property="Source" Value="c.png"/><!-- icon if [IsChecked] is [false] -->
          </Trigger>
        </ControlTemplate.Triggers>
      </ControlTemplate>
    </Setter.Value>
  </Setter>
</Style>

<Style TargetType="{x:Type My:MyCheckBox}" BasedOn="{StaticResource {x:Type CheckBox}}">
  <Style.Triggers>
    <Trigger Property="DefaultValue" Value="true">
      <!-- !!!!!!!!!!!!!!This need change [UriSource] in [CheckBoxStatusSource] to "TrueIfNull.png"!!!!!!!!!!!!!! -->
    </Trigger>
  </Style.Triggers>
</Style>

也许还有另一种解决方案

Answer 1

除非您出于其他原因需要延长CheckBox，否则您在此处尝试执行的操作也可以通过附加属性完成，并且您可以使用一个Style你所有的CheckBoxes。

public static class CheckBoxExtensions
{
    public static void SetDefaultValue(CheckBox element, bool value)
    {
        element.SetValue(DefaultValueProperty, value);
    }
    public static bool GetDefaultValue(CheckBox element)
    {
        return (bool)element.GetValue(DefaultValueProperty);
    }
    // Using a DependencyProperty as the backing store for DefaultValue.  This enables animation, styling, binding, etc...
    public static readonly DependencyProperty DefaultValueProperty =
        DependencyProperty.RegisterAttached("DefaultValue", typeof(bool), typeof(CheckBoxExtensions), new UIPropertyMetadata(false));
}

此属性现在可供您在解决方案中的任何CheckBox以及用于CheckBox的任何样式和模板中使用。在这种情况下......

<Style TargetType="{x:Type CheckBox}">
  <Style.Resources>
    <Imaging:BitmapImage x:Key="CheckBoxStatusSourceFalse" UriSource="FalseIfNull.png"/> <!-- icon if [IsChecked] is [null] and [DefaultValue] is [false] -->
    <Imaging:BitmapImage x:Key="CheckBoxStatusSourceTrue" UriSource="TrueIfNull.png"/> <!-- icon if [IsChecked] is [null] and [DefaultValue] is [true] -->
  </Style.Resources>
  <Setter Property="Template">
    <Setter.Value>
      <ControlTemplate TargetType="{x:Type CheckBox}">
        <Image x:Name="CheckBoxStatus" Source="{DynamicResource CheckBoxStatusSourceFalse}"/>
        <ControlTemplate.Triggers>
          <MultiTrigger>
            <MultiTrigger.Conditions>
              <Condition Property="local:CheckBoxExtensions.DefaultValue" Value="True" />
              <Condition Property="IsChecked" Value="{x:Null}" />
            </MultiTrigger.Conditions>
            <Setter TargetName="CheckBoxStatus" Property="Source" Value="{DynamicResource CheckBoxStatusSourceFalse}"/>
          </MultiTrigger>
          <Trigger Property="IsChecked" Value="True">
            <Setter TargetName="CheckBoxStatus" Property="Source" Value="b.png"/><!-- icon if [IsChecked] is [true] -->
          </Trigger>
          <Trigger Property="IsChecked" Value="False">
            <Setter TargetName="CheckBoxStatus" Property="Source" Value="c.png"/><!-- icon if [IsChecked] is [false] -->
          </Trigger>
        </ControlTemplate.Triggers>
      </ControlTemplate>
    </Setter.Value>
  </Setter>
</Style>

编辑：即使您仍需要展开{{1}}，此样式也适用于常规CheckBox和CheckBox实施。只需创建另一个基于此的Style。

MyCheckBox

如果您想从代码隐藏中访问<Style TargetType="{x:Type My:MyCheckBox}" BasedOn="{StaticResource {x:Type CheckBox}}"> ... </Style>属性，可以这样做：

DefaultValue

在CheckBox中更改默认位图

1 个答案: