C# 以样式更改按钮的内容？

Change a button's content in a style?

提问by Thrash505

I'm trying to do something similar to this:

我正在尝试做类似的事情：

<Window x:Class="WpfApplication1.Window1"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">

    <Grid>
        <Button>
            <Button.Style>
                <Style TargetType="{x:Type Button}">
                    <Setter Property="Content"
                            Value="No mouse over" />
                    <Style.Triggers>
                        <Trigger Property="IsMouseOver"
                                 Value="True">
                            <Setter Property="Content">
                                <Setter.Value>
                                    <CheckBox Content="Mouse is over" />
                                </Setter.Value>
                            </Setter>
                        </Trigger>
                    </Style.Triggers>
                </Style>
            </Button.Style>
        </Button>
    </Grid>
</Window>

However, I get a run-time XamlParseException with a message of:

但是，我收到了一个运行时 XamlParseException 的消息：

Cannot add content of type 'System.Windows.Controls.CheckBox' to an object of type 'System.Object'. Error at object 'System.Windows.Controls.CheckBox

无法将“System.Windows.Controls.CheckBox”类型的内容添加到“System.Object”类型的对象。对象“System.Windows.Controls.CheckBox”处出错

I'm actually trying to draw different icons for the button's content depending on external conditions. So I'm actually trying to use a DataTrigger, but the example above simplifies the problem. Any ideas?

我实际上是在尝试根据外部条件为按钮的内容绘制不同的图标。所以我实际上是在尝试使用 DataTrigger，但上面的示例简化了问题。有任何想法吗？

回答by apandit

WARNING:This may not be the best or correct way to do it. Make sure you read the other answers on this page as well.

警告：这可能不是最好或正确的方法。请确保您也阅读此页面上的其他答案。

Pretty sure you'd want to use a control template in this sort of situation. Something like:

在这种情况下，您肯定希望使用控件模板。就像是：

<style>
    <Setter Property="Content">
        <Setter.Value>
            <ControlTemplate>
                <Image Img="something.jpg" />
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</style>

And add a control template in the trigger for the on-hover.

并在触发器中添加一个用于悬停的控件模板。

Here's a good link

这是一个很好的链接

回答by rmoore

The actual error is occurring because Visuals can not be directly set as a Setter value. You can get the behavior you are looking for though, by setting the ContentTemplate using a DataTemplate, or by creating your content as a resource, either specific to the button or located elsewhere.

发生实际错误是因为 Visuals 不能直接设置为 Setter 值。但是，您可以通过使用 DataTemplate 设置 ContentTemplate 或通过将内容创建为资源（特定于按钮或位于其他位置）来获得您正在寻找的行为。

<Button>
    <Button.Resources>
        <CheckBox x:Key="Local_MouseOverContent" Content="Mouse is over" />
    </Button.Resources>
    <Button.Style>
        <Style TargetType="{x:Type Button}">
            <Setter Property="Content" Value="No mouse over" />
            <Style.Triggers>
                <Trigger Property="IsMouseOver" Value="True">
                    <Setter Property="Content"
                            Value="{StaticResource Local_MouseOverContent}" />
                </Trigger>
            </Style.Triggers>
        </Style>
    </Button.Style>
</Button>

<Button>
    <Button.Style>
        <Style TargetType="{x:Type Button}">
            <Setter Property="Content" Value="No mouse over" />
            <Style.Triggers>
                <Trigger Property="IsMouseOver" Value="True">
                    <Setter Property="ContentTemplate">
                        <Setter.Value>
                            <DataTemplate DataType="Button">
                                <CheckBox Content="Mouse is over" />
                            </DataTemplate>
                        </Setter.Value>
                    </Setter>
                </Trigger>
            </Style.Triggers>
        </Style>
    </Button.Style>
</Button>

回答by Steve

If you are making a generic style to be used by buttons all around your app, you will get visual tree conflicts using the approach where the image is a resource. So the template is your only choice in that case.

如果您正在制作一个通用样式供您应用程序周围的按钮使用，则使用图像是资源的方法将导致视觉树冲突。因此，在这种情况下，模板是您唯一的选择。

回答by Rudolf

REMARK! Exactly your example works in .NET Framework 4without any Changes !!!!

评论！正是您的示例在.NET Framework 4 中工作，没有任何更改！！！！

  <Button>
        <Button.Style>
            <Style TargetType="{x:Type Button}">
                <Setter Property="Content"
                        Value="No mouse over" />
                <Style.Triggers>
                    <Trigger Property="IsMouseOver"
                             Value="True">
                        <Setter Property="Content">
                            <Setter.Value>
                                <CheckBox Content="Mouse is over" />
                            </Setter.Value>
                        </Setter>
                    </Trigger>
                </Style.Triggers>
            </Style>
        </Button.Style>
    </Button>