c# - TemplateBinding 到自定义控件上的 DependencyProperty 不起作用

Question

目前，我正在开发一个简单的自定义按钮，它使用用户提供的图像作为按下和正常状态的背景。我有很多按钮，所以我决定编写一个自定义按钮并为按下和正常状态的图片实现两个属性。

这是我正在使用的代码

public partial class ThemeableButton : Button
{
    public ThemeableButton()
    {
        InitializeComponent();
    }


    public static readonly DependencyProperty PressedContentBackgroundSourceProperty = DependencyProperty.Register(
                    "PressedContentBackgroundSource", typeof(ImageSource), typeof(ThemeableButton), null);
    public ImageSource PressedContentBackgroundSource
    {
        get { return (ImageSource)GetValue(PressedContentBackgroundSourceProperty); }
        set
        {
            (value as BitmapImage).CreateOptions = BitmapCreateOptions.BackgroundCreation; 
            SetValue(PressedContentBackgroundSourceProperty, value);
        }
    }


    public static readonly DependencyProperty NormalContentBackgroundSourceProperty =
        DependencyProperty.Register("NormalContentBackgroundSource", typeof(ImageSource), typeof(ThemeableButton), null);

    public ImageSource NormalContentBackgroundSource
    {
        get { return (ImageSource)GetValue(NormalContentBackgroundSourceProperty); }
        set
        {
            (value as BitmapImage).CreateOptions = BitmapCreateOptions.BackgroundCreation;
            SetValue(NormalContentBackgroundSourceProperty, value);
        }
    }
}

我把这个按钮的样式写成如下

        <Style x:Key="ThemeableButtonTemplate" TargetType="MJbox_UIComponents_Controls:ThemeableButton">
        <Setter Property="Background" Value="Transparent"/>
        <Setter Property="BorderBrush" Value="{StaticResource PhoneForegroundBrush}"/>
        <Setter Property="Foreground" Value="{StaticResource PhoneForegroundBrush}"/>
        <Setter Property="BorderThickness" Value="{StaticResource PhoneBorderThickness}"/>
        <Setter Property="FontFamily" Value="{StaticResource PhoneFontFamilySemiBold}"/>
        <Setter Property="FontSize" Value="{StaticResource PhoneFontSizeMediumLarge}"/>
        <Setter Property="Padding" Value="0"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="MJbox_UIComponents_Controls:ThemeableButton">
                    <Grid>
                        <VisualStateManager.VisualStateGroups>
                            <VisualStateGroup x:Name="CommonStates">
                                <VisualState x:Name="Normal">
                                    <Storyboard>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Source" Storyboard.TargetName="ButtonBackground">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{TemplateBinding NormalContentBackgroundSource}">
                                            </DiscreteObjectKeyFrame>
                                        </ObjectAnimationUsingKeyFrames>
                                    </Storyboard>
                                </VisualState>
                                <VisualState x:Name="Pressed">
                                    <Storyboard>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Source" Storyboard.TargetName="ButtonBackground">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{TemplateBinding PressedContentBackgroundSource}">
                                            </DiscreteObjectKeyFrame>
                                        </ObjectAnimationUsingKeyFrames>
                                    </Storyboard>
                                </VisualState>
                            </VisualStateGroup>
                        </VisualStateManager.VisualStateGroups>
                        <Border BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" CornerRadius="0">
                            <Image x:Name="ButtonBackground" Stretch="None" Source="{TemplateBinding NormalContentBackgroundSource}"/>
                        </Border>       
                    </Grid>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

我尝试了一个简单的例子

<Controls:ThemeableButton Style="{StaticResource ThemeableButtonTemplate}" x:Name="btnDidntNeedIt" NormalContentBackgroundSource="{Binding Source={StaticResource DefaultTheme}, Path=DidntHaveButtonUnselected}"
                                   PressedContentBackgroundSource="{Binding Source={StaticResource DefaultTheme}, Path=DidntHaveButtonSelected}"
         />

但图像没有显示，我尝试从样式中删除 TemplateBinding 并将其替换为图像文件的相关源，并且效果很好。我只是不想为应用程序上的每个按钮创建自定义样式。任何可能的解决方法？

Answer 1

我以前遇到过这种情况，TemplateBinding 不适用于控件上的自定义依赖属性。查看这些相关问题:

issues with template binding and binding of custom component

TemplateBinding does not work in certain cases(when using TranslateTransform)

我一直用这个代替:

{Binding MyProperty, RelativeSource={RelativeSource TemplatedParent}}

它在语义上与 TemplateBinding 相同，也可以支持值转换器等......