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我无法让此按钮（其内容中包含图像）正确更改ImageSource点击。这是我的 Xaml 和代码背后。

XAML：

<Window.Resources>
    <Style x:Key="NoChromeButton" TargetType="{x:Type Button}">
        <Setter Property="Background" Value="Transparent"/>
        <Setter Property="BorderThickness" Value="1"/>
        <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}"/>
        <Setter Property="HorizontalContentAlignment" Value="Center"/>
        <Setter Property="VerticalContentAlignment" Value="Center"/>
        <Setter Property="Padding" Value="1"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type Button}">
                    <Grid x:Name="Chrome" Background="{TemplateBinding Background}" SnapsToDevicePixels="true">
                        <ContentPresenter HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" Margin="{TemplateBinding Padding}" RecognizesAccessKey="True" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/>
                    </Grid>
                    <ControlTemplate.Triggers>
                        <Trigger Property="IsEnabled" Value="false">
                            <Setter Property="Foreground" Value="#ADADAD"/>
                            <Setter Property="Opacity" TargetName="Chrome" Value="0.5"/>
                        </Trigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
</Window.Resources>

<Grid>
    <Button x:Name="DrawCircleButton" Height="56" Width="157" 
    Margin="10,10,0,0" VerticalAlignment="Top" 
    HorizontalAlignment="Left" Click="DrawCircleButtonClick"
            Style="{DynamicResource NoChromeButton}"
    >
        <Image x:Name="imgButtonState" >
            <Image.Source>
                <BitmapImage UriSource="Resources/off.gif" />
            </Image.Source>
        </Image>
    </Button>
    <ScrollViewer Margin="0,50,0,0">
        <TextBlock Name="textBlock1" TextWrapping="Wrap" FontSize="20" FontWeight="Bold" />
    </ScrollViewer>


</Grid>

代码背后：

private void DrawCircleButtonClick(object sender, RoutedEventArgs e)
    {
        var t = ButtonState;
        ButtonState = t;
    }

public bool ButtonState
    {
        get
        {
            return (bool)GetValue(ButtonStateProperty);
        }
        set
        {
            var t = new BitmapImage(new Uri("Resource/on.gif", UriKind.Relative));

            DrawCircleButton.Content = !value ? imgButtonState.Source = new BitmapImage(new Uri("on.gif", UriKind.Relative)) : imgButtonState.Source = new BitmapImage(new Uri("off.gif", UriKind.Relative));
            SetValue(ButtonStateProperty, !value);
        }
    }

    public static readonly DependencyProperty ButtonStateProperty = DependencyProperty.Register("ButtonState", typeof(bool), typeof(bool));

因此，最初，该按钮设置为“关闭”。但是当它被点击时，它会在“开”和“关”之间切换。我确定我做错了什么，因为显示的是图像路径的文本。有任何想法吗？

4

2 回答 2

1

首先，WPF 也有一个ToggleButton。也许这在这里可能更合适。

现在你的错误。它基本上在以下行中：

DrawCircleButton.Content = !value ? imgButtonState.Source = new BitmapImage(new Uri("on.gif", UriKind.Relative)) : imgButtonState.Source = new BitmapImage(new Uri("off.gif", UriKind.Relative));

您将新的 BitmapImage 分配给 Button 的 Content 属性。由于 Button 的 ContentPresenter 无法处理该类型，它只显示 ToString() 的结果。如果您只是放弃作业并编写以下内容，它将起作用。内容没有改变，只是图像的来源已经是按钮的内容。

imgButtonState.Source = value
    ? new BitmapImage(new Uri("on.gif", UriKind.Relative))
    : new BitmapImage(new Uri("off.gif", UriKind.Relative));

但是，您的依赖属性的定义仍然存在严重问题ButtonState。如果你想这样定义它，你必须从 Button 派生并编写如下声明：

public class MyButton : Button
{
    public static readonly DependencyProperty ButtonStateProperty =
        DependencyProperty.Register(
            "ButtonState", typeof(bool), typeof(MyButton),
            new FrameworkPropertyMetadata(ButtonStatePropertyChanged));

    public bool ButtonState
    {
        get { return (bool)GetValue(ButtonStateProperty); }
        set { SetValue(ButtonStateProperty, value); }
    }

    private static void ButtonStatePropertyChanged(DependencyObject obj, DependencyPropertyChangedEventArgs e)
    {
        ((MyButton)obj).imgButtonState.Source = (bool)e.NewValue
            ? new BitmapImage(new Uri("on.gif", UriKind.Relative))
            : new BitmapImage(new Uri("off.gif", UriKind.Relative));
    }
}

You should also not do anything else expect GetValue/SetValue in the CLR wrappers of a dependency property. Instead you should use a PropertyChangedCallback as shown above. See the Implementing the Wrapper section in Checklist for Defining a Dependency Property.

If you don't want to derive from Button, you could alternatively define ButtonState as an attached property.

于 2012-11-05T07:46:48.017 回答
0

使用Image而不是BitmapImage作为Button的内容。此外，使用Image.Source = "/Resources/YourFile.png"而不是在 XAML 和代码中声明位图图像。

于 2012-11-05T03:11:20.847 回答