无法基于 DependencyProperty 将样式应用于 RichTextBox 元素

Question

我有一个继承 RichTextBox（我将其称为 MyRichTextBox）的控件，其中 DependencyProperty 定义了某些文本元素类型的样式。与 ItemsControl.ItemContainerStyle 类似，此样式将基于每个实例应用于它的某些子项。

我试过两种不同的方法，但两种方法都不起作用：

在创建文本元素（继承 Button 并托管在 InlineUIContainer 中的控件；我们称之为 MyTextElement）时，我会创建一个新样式基于 MyRichTextBox.ItemContainerStyle 并指定 MyTextElement 新样式。
当MyRichTextBox.ItemContainerStyle改变时，在MyRichTextBox.ItemContainerStyle的基础上创建一个新样式并添加到MyRichTextBox的资源中。

这两种方法都会导致以下意外异常：

An unhandled exception of type 'MS.Internal.PtsHost.UnsafeNativeMethods.PTS.SecondaryException' occurred in PresentationFramework.dll

没有提供其他信息，在研究此异常时，我没有发现任何与 RichTextBox 或以编程方式分配样式相关的内容。一些文章表明错误是线程问题；但是，我并没有尝试在不同的线程上创建样式 creating/assigning 样式 without 基于 MyRichTextBox.ItemContainerStyle does 工作。

这是控件使用方法 #2 的样子（为简洁起见，我排除了方法 #1，因为它做同样的事情，只是方式不同）：

public class MyRichTextBox : RichTextBox
{
    public static DependencyProperty ItemContainerStyleProperty = DependencyProperty.Register("ItemContainerStyle", typeof(Style), typeof(MyRichTextBox), new FrameworkPropertyMetadata(default(Style), FrameworkPropertyMetadataOptions.BindsTwoWayByDefault, OnItemContainerStyleChanged));
    public Style ItemContainerStyle
    {
        get
        {
            return (Style)GetValue(ItemContainerStyleProperty);
        }
        set
        {
            SetValue(ItemContainerStyleProperty, value);
        }
    }
    static void OnItemContainerStyleChanged(DependencyObject Object, DependencyPropertyChangedEventArgs e)
    {
        (Object as MyRichTextBox).OnItemContainerStyleChanged((Style)e.OldValue, (Style)e.NewValue);
    }

    protected virtual void OnItemContainerStyleChanged(Style OldValue, Style NewValue)
    {
        //Make sure the old style is gone
        if (OldValue != null)
            Resources.Remove(OldValue.TargetType);

        if (NewValue != null)
        {
            //This line does not attempt to utilize the specified style, but is stable
            Resources.Add(NewValue.TargetType, new Style(NewValue.TargetType));

            //This line attempts to utilize the specified style, but is unstable
            Resources.Add(NewValue.TargetType, new Style(NewValue.TargetType, NewValue));
        }
    }
}

最终，我希望能够做到这一点：

<Controls:MyRichTextBox>
    <Controls:MyRichTextBox.ItemContainerStyle>
        <Style TargetType="{x:Type Controls:MyTextElement}">
            <!-- Whatever... -->
        </Style>
    </Controls:MyRichTextBox.ItemContainerStyle>
</Controls:MyRichTextBox>

这应该允许我为 MyRichTextBox 中类型为 MyTextElement 的所有元素定义样式。方法 #1 会给出相同的结果，但两种方法都失败并出现相同的错误。

因为分配新样式 而不是 基于 MyRichTextBox.ItemContainerStyle 是可行的，所以不清楚我做错了什么导致了这个错误。

编辑： MyTextElement 看起来像这样：

public class MyTextElement : Button
{
    public MyTextElement() : base()
    {
    }
}

MyRichTextBox 的有效逻辑结构如下所示：

<Controls:MyRichTextBox>
    <FlowDocument>
        <Paragraph>
            <InlineUIContainer>
                <Controls:MyTextElement Content="My Content"/>
            </InlineUIContainer>
         </Paragraph >
     </FlowDocument>
 </Controls:MyRichTextBox>

Answer 1

您只能将一个键为 NewValue.TargetType 的资源添加到 ResourceDictionary。

以下示例代码对我来说工作正常：

public class MyTextElement : Run { }

public class MyRichTextBox : RichTextBox
{
    public static DependencyProperty ItemContainerStyleProperty = DependencyProperty.Register("ItemContainerStyle", typeof(Style), typeof(MyRichTextBox), new FrameworkPropertyMetadata(default(Style), FrameworkPropertyMetadataOptions.BindsTwoWayByDefault, OnItemContainerStyleChanged));
    public Style ItemContainerStyle
    {
        get
        {
            return (Style)GetValue(ItemContainerStyleProperty);
        }
        set
        {
            SetValue(ItemContainerStyleProperty, value);
        }
    }
    static void OnItemContainerStyleChanged(DependencyObject Object, DependencyPropertyChangedEventArgs e)
    {
        (Object as MyRichTextBox).OnItemContainerStyleChanged((Style)e.OldValue, (Style)e.NewValue);
    }

    protected virtual void OnItemContainerStyleChanged(Style OldValue, Style NewValue)
    {
        //Make sure the old style is gone
        if (OldValue != null)
            Resources.Remove(OldValue.TargetType);

        if (NewValue != null)
        {
            //This line does not attempt to utilize the specified style, but is stable
            //Resources.Add(NewValue.TargetType, new Style(NewValue.TargetType));

            //This line attempts to utilize the specified style, but is unstable
            Resources.Add(NewValue.TargetType, new Style(NewValue.TargetType, NewValue));
        }
    }
}

<Controls:MyRichTextBox>
    <Controls:MyRichTextBox.ItemContainerStyle>
        <Style TargetType="{x:Type Controls:MyTextElement}">
            <Setter Property="Foreground" Value="Red" />
        </Style>
    </Controls:MyRichTextBox.ItemContainerStyle>
    <FlowDocument>
        <Paragraph>
            <Run Text="default" />
            <Controls:MyTextElement Text="red" />
        </Paragraph>
    </FlowDocument>
</Controls:MyRichTextBox>

编辑：

MyTextElement inherits Button and is assigned as the child of InlineUIContainer; ultimately, the style needs to apply to MyTextElement, NOT a Run. Your MyTextElement inherits Run and isn't a child of anything

这也有效：

public class MyTextElement : Button
{
    public MyTextElement() : base()
    {
    }
}

public class MyRichTextBox : RichTextBox
{
    public static DependencyProperty ItemContainerStyleProperty = DependencyProperty.Register("ItemContainerStyle", 
        typeof(Style), typeof(MyRichTextBox), new FrameworkPropertyMetadata(default(Style), 
            FrameworkPropertyMetadataOptions.BindsTwoWayByDefault, OnItemContainerStyleChanged));
    public Style ItemContainerStyle
    {
        get
        {
            return (Style)GetValue(ItemContainerStyleProperty);
        }
        set
        {
            SetValue(ItemContainerStyleProperty, value);
        }
    }
    static void OnItemContainerStyleChanged(DependencyObject Object, DependencyPropertyChangedEventArgs e)
    {
        (Object as MyRichTextBox).OnItemContainerStyleChanged((Style)e.OldValue, (Style)e.NewValue);
    }

    protected virtual void OnItemContainerStyleChanged(Style OldValue, Style NewValue)
    {
        //Make sure the old style is gone
        if (OldValue != null)
            Resources.Remove(OldValue.TargetType);

        if (NewValue != null)
        {
            Resources.Add(NewValue.TargetType, new Style(NewValue.TargetType, NewValue));
        }
    }
}

<Controls:MyRichTextBox IsDocumentEnabled="True">
    <Controls:MyRichTextBox.ItemContainerStyle>
        <Style TargetType="{x:Type Controls:MyTextElement}">
            <Setter Property="Foreground" Value="Red" />
        </Style>
    </Controls:MyRichTextBox.ItemContainerStyle>
    <FlowDocument>
        <Paragraph>
            <InlineUIContainer>
                <Controls:MyTextElement Content="My Content"/>
            </InlineUIContainer>
        </Paragraph >
    </FlowDocument>
</Controls:MyRichTextBox>

请注意，我已从 OnItemContainerStyleChanged 方法中删除了以下行：

Resources.Add(NewValue.TargetType, new Style(NewValue.TargetType));

无法基于 DependencyProperty 将样式应用于 RichTextBox 元素

Can't apply style to RichTextBox elements based on DependencyProperty

c#

wpf

xaml

richtextbox

dependency-properties