WPF报错“Binding仅能设置于DependencyObject的DependencyProperty”求助

我写了一段WPF XAML代码，运行时抛出错误：“binding can only be set in dependencyproperty of dependencyobject”，搞不懂错误原因，也不明白为什么要加依赖项。

出错的XAML代码 #

<Window x:Class="Kiosk.DeleteMenu.DeleteMenuWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:Kiosk.DeleteMenu"
        mc:Ignorable="d"
        Title="DeleteMenuWindow" Height="800" Width="800">
    <Grid>

        <ListBox ItemsSource="{Binding Menus}" Width="800">
            <ItemsControl.ItemsPanel>
                <ItemsPanelTemplate>
                    <WrapPanel Width="800"/>
                </ItemsPanelTemplate>
            </ItemsControl.ItemsPanel>
            <ListBox.ItemTemplate>
                <DataTemplate>
                    <Border BorderThickness="1" BorderBrush="Black" Width="250" Background="Transparent">
                        <StackPanel Orientation="Vertical" Width="250">
                            <StackPanel.InputBindings>
                                <MouseBinding MouseAction="LeftClick" Command="{Binding StackPanelClickCommands}"  CommandParameter="{Binding ElementName=lb_MenuText, Path=Content}"></MouseBinding>
                            </StackPanel.InputBindings>
                            <Image Width ="150" Height="150" Stretch="Uniform" StretchDirection="Both" Source="{Binding Path = MenuImagetoBS}">
                            </Image>
                            <Border BorderThickness="1" BorderBrush="Silver">
                                <Label x:Name ="lb_MenuText" Content="{Binding Path = MenuText}"></Label>
                            </Border>
                            <Label Content="{Binding Path = MenuKind}"></Label>
                        </StackPanel>
                    </Border>
                </DataTemplate>
                </ListBox.ItemTemplate>
            </ListBox>
    </Grid>
</Window>

尝试的修改 #

我把MouseBinding从StackPanel移到Image元素里，但错误依然存在：

<Image.InputBindings>
    <MouseBinding MouseAction="LeftClick" Command="{Binding StackPanelClickCommands}"  CommandParameter="{Binding ElementName=lb_MenuText, Path=Content}"></MouseBinding>
</Image.InputBindings>

可正常运行的对比代码 #

但我另一个项目里的类似代码能正常运行：

<Image Margin="757,222,312,373">
        <Image.Resources>
            <Style TargetType="{x:Type Image}">
                <!-- Default image -->
                <Setter Property="Source" Value="Resources/DefaultPoint.png"/>
                <Style.Triggers>
                    <Trigger Property="IsMouseOver" Value="True">
                        <!-- Hover image -->
                        <Setter Property="Source" Value="Resources/MapPoint.png"/>
                    </Trigger>
                </Style.Triggers>
            </Style>
        </Image.Resources>
        <Image.ToolTip>
            <ToolTip x:Name="USToolTip2" Width="250">
                <StackPanel Background="White" Width="250">
                    <TextBlock FontWeight="Bold" Width="{Binding ActualWidth, ElementName=USToolTip}"><Run  Foreground="Red" Text=" : " /><Run Text=" "/><Run  Foreground="Black" Text="{Binding Covid.Country}"/></TextBlock>
                    <TextBlock FontWeight="Bold"><Run  Foreground="Red" Text=": "/><Run Text=" "/><Run  Foreground="Black" Text="{Binding Covid.Confirmedcase}"/></TextBlock>
                    <TextBlock FontWeight="Bold"><Run  Foreground="Red" Text=": "/><Run Text=" "/><Run  Foreground="Black" Text="{Binding Covid.Dead}"/></TextBlock>
                    <TextBlock FontWeight="Bold"><Run  Foreground="Red" Text=": "/><Run Text=" "/><Run  Foreground="Black" Text="{Binding Covid.Cured}"/></TextBlock>
                    <TextBlock FontWeight="Bold"><Run  Foreground="Red" Text=": "/><Run Text=" "/><Run  Foreground="Black" Text="{Binding Covid.Fatality}"/></TextBlock>
                    <TextBlock FontWeight="Bold"><Run  Foreground="Red" Text=": "/><Run Text=" "/><Run  Foreground="Black" Text="{Binding Covid.CuredPercent}"/></TextBlock>
                    <TextBlock FontWeight="Bold"><Run  Foreground="Red" Text=": "/><Run Text=" "/><Run  Foreground="Black" Text="{Binding Covid.Incidence}"/></TextBlock>
                </StackPanel>
            </ToolTip>
        </Image.ToolTip>
        <Image.InputBindings>
            <MouseBinding MouseAction="LeftClick" Command="{Binding MapPointCommand}" CommandParameter="🇮🇳"/>

        </Image.InputBindings>

错误原因与解决方案 #

核心错误原因 #

问题出在**MouseBinding的CommandParameter属性**：

• MouseBinding不是DependencyObject，它的CommandParameter是普通CLR属性，不支持数据绑定。直接给它绑定ElementName，就会触发“只能在DependencyObject的DependencyProperty上设置绑定”的错误。
• 另一个项目的代码是给CommandParameter赋了常量值🇮🇳，没有用绑定，所以不会触发这个限制。

两种修复方案 #

方案1：直接绑定数据项的属性

既然lb_MenuText的Content绑定的是MenuText，直接绑定这个属性即可，不用通过元素查找：

<MouseBinding MouseAction="LeftClick" 
              Command="{Binding StackPanelClickCommands}" 
              CommandParameter="{Binding MenuText}"/>

方案2：用DependencyProperty中转绑定

如果必须通过元素获取值，可以先把目标值存到父元素的Tag属性（Tag是DependencyProperty，支持绑定），再绑定Tag：

<StackPanel Orientation="Vertical" Width="250" 
            Tag="{Binding ElementName=lb_MenuText, Path=Content}">
    <StackPanel.InputBindings>
        <MouseBinding MouseAction="LeftClick" 
                      Command="{Binding StackPanelClickCommands}" 
                      CommandParameter="{Binding Tag, RelativeSource={RelativeSource AncestorType=StackPanel}}"/>
    </StackPanel.InputBindings>
    <!-- 其余元素保持不变 -->
</StackPanel>

内容的提问来源于stack exchange，提问作者junsuchoi