c# - WPF:ControlTemplate 的 IsPressed 触发器不起作用

Question

我使用名为 ImageButton 的自定义控件来显示具有不同图像的按钮。 ImageButton 包含依赖属性:

public ImageSource DisabledImageSource
    {
        get { return (ImageSource)GetValue(DisabledImageSourceProperty); }
        set { SetValue(DisabledImageSourceProperty, value); }
    }


    public ImageSource NormalImageSource
    {
        get { return (ImageSource)GetValue(NormalImageSourceProperty); }
        set { SetValue(NormalImageSourceProperty, value); }
    }

    public ImageSource HoverImageSource
    {
        get { return (ImageSource)GetValue(HoverImageSourceProperty); }
        set { SetValue(HoverImageSourceProperty, value); }
    }

    public ImageSource PushedImageSource
    {
        get { return (ImageSource)GetValue(PushedImageSourceProperty); }
        set { SetValue(PushedImageSourceProperty, value); }
    }


    public static readonly DependencyProperty DisabledImageSourceProperty =
        DependencyProperty.Register("DisabledImageSource", typeof(ImageSource), typeof(ImageButton), new UIPropertyMetadata());


    public static readonly DependencyProperty NormalImageSourceProperty =
        DependencyProperty.Register("NormalImageSource", typeof(ImageSource), typeof(ImageButton), new UIPropertyMetadata());


    public static readonly DependencyProperty HoverImageSourceProperty =
        DependencyProperty.Register("HoverImageSource", typeof(ImageSource), typeof(ImageButton), new UIPropertyMetadata());

    public static readonly DependencyProperty PushedImageSourceProperty =
        DependencyProperty.Register("PushedImageSource", typeof(ImageSource), typeof(ImageButton), new UIPropertyMetadata());

它的样式定义如下:

<Style TargetType="{x:Type local:ImageButton}">
    <Setter Property="HorizontalAlignment" Value="Left"/>
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type Button}">
                <Grid>
                    <Image Name="image" Source="{Binding NormalImageSource, RelativeSource={RelativeSource TemplatedParent}}" Stretch="None" />
                </Grid>
                <ControlTemplate.Triggers>                    
                    <Trigger Property="IsEnabled" Value="False">
                        <Setter TargetName="image" Property="Source" Value="{Binding DisabledImageSource, RelativeSource={RelativeSource TemplatedParent}}"/>
                    </Trigger>
                    <Trigger Property="Button.IsPressed" Value="True">
                        <Setter TargetName="image" Property="Source"  Value="{Binding PushedImageSource, RelativeSource={RelativeSource TemplatedParent}}"/>
                    </Trigger>
                    <MultiTrigger>
                        <MultiTrigger.Conditions>
                            <Condition Property="IsMouseOver" Value="True" />
                        </MultiTrigger.Conditions>
                        <Setter TargetName="image" Property="Source" Value="{Binding HoverImageSource, RelativeSource={RelativeSource TemplatedParent}}"/>
                    </MultiTrigger>
                </ControlTemplate.Triggers>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

除 IsPressed 外，一切正常。我永远看不到我在 PushedImageSource 中设置的图像，我也不知道为什么。 任何帮助将不胜感激:)

编辑 1:

这是测试它的 xaml 代码

<Window x:Class="SMEClient.WPF.Tester.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:is="clr-namespace:Project1.SearchBox;assembly=Project1"
        Title="MainWindow" Height="350" Width="525">
    <Window.Resources>
        <ResourceDictionary>
            <ResourceDictionary.MergedDictionaries>
                <ResourceDictionary Source="pack://application:,,,/Project1;component/SearchBox/ImageButton.xaml"/>
            </ResourceDictionary.MergedDictionaries>
        </ResourceDictionary>
    </Window.Resources>
    <Grid>
        <StackPanel>
            <is:ImageButton NormalImageSource="C:\Users\Public\Pictures\Sample Pictures\Koala.jpg"
                            PushedImageSource="C:\Users\Public\Pictures\Sample Pictures\Chrysanthemum.jpg"
                            HoverImageSource="C:\Users\Public\Pictures\Sample Pictures\Jellyfish.jpg"/>
        </StackPanel>
    </Grid>
</Window>

Answer 1

您的触发器不是互斥的，在这种情况下，触发器添加到 Triggers 的顺序收藏开始发挥作用。你的最后一个触发器 IsMouseOver覆盖 Source IsPressed 之后的属性(property)触发器设置正确的图像，因为只有在鼠标悬停时才会按下按钮(当然是在使用鼠标时)。

尝试设置 IsPressed在 Triggers 中最后触发集合，以及 IsPressed即使 IsMouseOver 也会应用触发器也是如此。