c# - 如何更改 WPF 中的按钮样式，由 bool 值触发？

Question

我需要一个 Button，它会在每次 bool 值 (IsFavourite) 发生变化时更改其背景图像。 我用 DataTrigger 试过，但他不知道属性:“Source”。你能帮帮我吗，我不是那么喜欢 xaml 代码:-(

<Style x:Key="starButtonStyle" TargetType="{x:Type Button}">
    <Setter Property="IsEnabled" Value="True" />
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate>
                <Image x:Name="PART_img" Source="/FtpUploadClient;component/media/star_off_48.png" Height="28" Width="28" HorizontalAlignment="Center" VerticalAlignment="Center"/>
                <ControlTemplate.Triggers>
                    <Trigger Property="IsMouseOver" Value="True">
                        <Setter TargetName="PART_img"
                        Property="Source"
                        Value="/FtpUploadClient;component/media/star_48.png" />
                    </Trigger>
                    <DataTrigger Binding="{Binding Path=IsFavourite}" Value="True">
                        <Setter Property="Source" Value="/FtpUploadClient;component/media/star_48.png" />
                    </DataTrigger>
                    <DataTrigger Binding="{Binding Path=IsFavourite}" Value="False">
                        <Setter Property="Source" Value="/FtpUploadClient;component/media/star_off_48.png" />
                    </DataTrigger>
                </ControlTemplate.Triggers>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

---

private void StarButton_Click(object sender, RoutedEventArgs e)
{
    IsFavourite = !IsFavourite;
}

private bool isFavourite = false;
public bool IsFavourite
{
    get { return isFavourite; }
    set
    {
        isFavourite = value;
        OnPropertyChanged("IsFavourite");
    }
}


public event PropertyChangedEventHandler PropertyChanged;

protected void OnPropertyChanged(string name)
{
    PropertyChangedEventHandler handler = PropertyChanged;
    if (handler != null)
    {
        handler(this, new PropertyChangedEventArgs(name));
    }
}

-- 按钮事件 Click 调用一个改变 IsFavourite 的方法:

<Button Content="Star" Style="{DynamicResource starButtonStyle}" Click="StarButton_Click" />

Answer 1

将触发器添加到图像样式而不是 ControlTemplate

<Image HorizontalAlignment="Center" VerticalAlignment="Center" Height="28" Width="28">
    <Image.Style>
        <Style TargetType="{x:Type Image}">
            <Setter Property="Source" Value="/FtpUploadClient;component/media/star_off_48.png" />
            <Style.Triggers>
                <Trigger Property="IsMouseOver" Value="True">
                    <Setter Property="Source" Value="/FtpUploadClient;component/media/star_48.png" />
                </Trigger>
                <DataTrigger Binding="{Binding Path=IsFavourite}" Value="True">
                    <Setter Property="Source" Value="/FtpUploadClient;component/media/star_48.png" />
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </Image.Style>
</Image>