DataTemplate 内部的交互触发器不适用于 XamlReader

Question

我正在尝试使用 XamlReader.Load() 解析在代码隐藏中动态创建的 DataTemplate（对于 WPF 数据网格）:

DataTemplate dataTemplate;

StringReader template = new StringReader($@"
<DataTemplate
    xmlns=""http://schemas.microsoft.com/winfx/2006/xaml/presentation""
    xmlns:x=""http://schemas.microsoft.com/winfx/2006/xaml""
    xmlns:local=""clr-namespace:MyApp;assembly=MyApp"">
<DataTemplate.Resources>
    <local:ArrayMultiValueConverter x:Key=""arrayMultiValueConverter""/>
</DataTemplate.Resources>
    <StackPanel Orientation=""Vertical"">
        <Expander VerticalAlignment=""Center"" xmlns:i=""http://schemas.microsoft.com/xaml/behaviors"">
        <i:Interaction.Triggers>
            <i:EventTrigger EventName=""IsExpanded"">
                <i:InvokeCommandAction Command=""{{Binding DataContext.TextFilterColumn}}""/>
            </i:EventTrigger>
        </i:Interaction.Triggers>
            <Expander.Header>
                <TextBlock x:Name=""{dtColumnName}"" VerticalAlignment=""Center"" Text=""{{TemplateBinding Content}}"" Margin=""5,5,5,0"" FontWeight=""SemiBold""/>
            </Expander.Header>
            <StackPanel Orientation=""Horizontal"">
                <TextBox x:Name=""{"TbxFilter" + dtColumnName}"" Width=""100"" Margin=""5""/>
                <TextBlock Margin=""0,0,5,0"" VerticalAlignment=""Center"" FontFamily=""Segoe MDL2 Assets"">
                    <Hyperlink TextDecorations=""{{x:Null}}"" Command=""{{Binding DataContext.FilterColumnName, RelativeSource={{RelativeSource FindAncestor, AncestorType={{x:Type Window}}}}}}"">
                        <Hyperlink.CommandParameter>
                            <MultiBinding Converter=""{{StaticResource arrayMultiValueConverter}}"">
                                <Binding Path=""Text"" ElementName=""{dtColumnName}"" />
                                <Binding Path=""Text"" ElementName=""{"TbxFilter" + dtColumnName}"" />
                            </MultiBinding>
                        </Hyperlink.CommandParameter>   
                        &#xE721;
                    </Hyperlink>
                </TextBlock>
                <TextBlock Margin=""0,0,5,0"" VerticalAlignment=""Center"" FontFamily=""Segoe MDL2 Assets"">
                    <Hyperlink TextDecorations=""{{x:Null}}"" Command=""{{Binding DataContext.FilterColumnName, RelativeSource={{RelativeSource FindAncestor, AncestorType={{x:Type Window}}}}}}"">
                        <Hyperlink.CommandParameter>
                            <MultiBinding Converter=""{{StaticResource arrayMultiValueConverter}}"">
                                <Binding Path=""Text"" ElementName=""{dtColumnName}""/>
                                <Binding Path=""Text"" RelativeSource=""{{RelativeSource FindAncestor, AncestorType={{x:Type TextBlock}}}}""/>
                            </MultiBinding>
                        </Hyperlink.CommandParameter>
                        &#xe75c;
                    </Hyperlink>
                </TextBlock>
            </StackPanel>
        </Expander>
    </StackPanel>
</DataTemplate>
");

XmlReader xmlReader = XmlReader.Create(template);
dataTemplate = XamlReader.Load(xmlReader) as DataTemplate;

textColumn.HeaderTemplate = dataTemplate;

当我删除这部分代码时一切正常:

<i:Interaction.Triggers>
    <i:EventTrigger EventName=""IsExpanded"">
        <i:InvokeCommandAction Command=""{{Binding DataContext.TextFilterColumn}}""/>
    </i:EventTrigger>
</i:Interaction.Triggers>

但是当我添加它时，有一个 Exception Thrown :

System.Windows.Markup.XamlParseException: ''Cannot set unknown member '{http://schemas.microsoft.com/xaml/behaviors}Interaction.Triggers'.' Line number '11' and line position '10'.'

我在本文之后使用“XAML 行为”（但 Interactivity 也是如此）：

https://devblogs.microsoft.com/dotnet/open-sourcing-xaml-behaviors-for-wpf/

这似乎是 XamlReader.Load(xmlReader) 的问题。

如果有人知道解决方法，我将不胜感激。

配置：

框架 4.8（试用 4.7.2）
Microsoft.Xaml.Behaviors.Wpf 1.1.39

谢谢。

Answer 1

XamlReader.Load 的文档中未提及，但 XAML 命名空间映射中引用的任何自定义程序集必须已可供应用程序使用。

你有两个选择：

1.Load 程序集 Microsoft.Xaml.Behaviors 或在读取 xaml 输入之前从程序集中初始化某些类型。

Assembly assembly = Assembly.LoadFrom("Microsoft.Xaml.Behaviors.dll");

或

var et = new Microsoft.Xaml.Behaviors.EventTrigger();

2.Use xaml

中的 CLR 命名空间声明

xmlns:i=""clr-namespace:Microsoft.Xaml.Behaviors;assembly=Microsoft.Xaml.Behaviors""

DataTemplate 内部的交互触发器不适用于 XamlReader

Interaction triggers inside DataTemplate not working with XamlReader

c#

wpf

eventtrigger

xamlreader