WPF - 绑定数据模板答案

【问题标题】：WPF - Binding data templateWPF - 绑定数据模板
【发布时间】：2021-03-15 12:06:03
【问题描述】：

我正在尝试在 Telerik RadDiagram ShapeStyle 上绑定 <DataTemplate>：

<telerik:RadDiagram x:Name="Diagram"
                            ShapeStyle="{StaticResource NodeStyle}"
                            GraphSource="{Binding GraphSource}"/>

这种风格看起来像这样：

    <Grid.Resources>
        <Style x:Key="NodeStyle" TargetType="telerik:RadDiagramShape">
            <Setter Property="Position" Value="{Binding Position, Mode=TwoWay}" />
            <Setter Property="Content" Value="{Binding}" />
            <Setter Property="Geometry" Value="{telerik:CommonShape ShapeType=RectangleShape}" />
            <Setter Property="ContentTemplate" >
                <Setter.Value>
                    <MultiBinding Converter="{StaticResource StyleConverter}">
                        <Binding RelativeSource="{RelativeSource Mode=FindAncestor, AncestorType=UserControl}"/>
                        <Binding Path=""/>
                    </MultiBinding>
                </Setter.Value>
            </Setter>
        </Style>
...
</Grid.Resources>

样式转换器：

class StyleConverter : IMultiValueConverter
{
    public object Convert(object[] values, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        FrameworkElement targetElement = values[0] as FrameworkElement;

        if (values[0] is BilledMsisdnViewModel)
            return targetElement.FindResource("BilledMsisdnControl");
        else if(values[0] is BilledImeiViewModel)
            return targetElement.FindResource("ImeiControl");

        return null;
    }

    public object[] ConvertBack(object value, Type[] targetTypes, object parameter, System.Globalization.CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

这些资源（BilledMsisdnControl 和 ImeiControl）在 <UserControl.Resources> 中定义：

<UserControl.Resources>
    <ResourceDictionary>
        <local:BilledMsisdnControl x:Key="BilledMsisdnControl"/>
        <local:ImeiControl x:Key="ImeiControl"/>
        <local:StyleConverter x:Key="StyleConverter"/>
    </ResourceDictionary>
</UserControl.Resources>

它们是由我的用户控件创建的。

所以我这里的目标是根据绑定视图模型类型选择用户控件（这部分工作），然后将其用作ContentTemplate（这不起作用）。我只在图表节点中获得 ImeiControl 或 BilledMsisdnControl 的对象命名空间和名称。

我该如何解决这个问题？

【问题讨论】：

标签： wpf data-binding telerik

【解决方案1】：

根据documentation，您应该使用样式选择器

public class NodeStyleSelector : StyleSelector 
{ 
    public Style BilledMsisdnStyle { get; set; } 
    public Style BilledImeiStyle { get; set; } 
 
    public override Style SelectStyle(object item, DependencyObject container) 
    { 
        if (item is BilledMsisdnViewModel) 
            return BilledMsisdnStyle; 
        else if (item is BilledImeiViewModel) 
            return BilledImeiStyle; 
        else return base.SelectStyle(item, container); 
    } 
}

使用ContentTemplate 定义样式。在 ContentTemplate 中添加您的用户控件。

<Style x:Key="BilledMsisdnStyle" TargetType="telerik:RadDiagramShape">
    <Setter Property="Position" Value="{Binding Position, Mode=TwoWay}" />
    <Setter Property="Content" Value="{Binding}" />
    <Setter Property="Geometry" Value="{telerik:CommonShape ShapeType=RectangleShape}" />
    <Setter Property="ContentTemplate" >
        <Setter.Value> 
            <DataTemplate> 
                <local:BilledMsisdnControl/> 
            </DataTemplate> 
        </Setter.Value> 
    </Setter>
</Style>


<Style x:Key="BilledImeiStyle" TargetType="telerik:RadDiagramShape">
    <Setter Property="Position" Value="{Binding Position, Mode=TwoWay}" />
    <Setter Property="Content" Value="{Binding}" />
    <Setter Property="Geometry" Value="{telerik:CommonShape ShapeType=RectangleShape}" />
    <Setter Property="ContentTemplate" >
        <Setter.Value> 
            <DataTemplate> 
                <local:ImeiControl/> 
            </DataTemplate> 
        </Setter.Value> 
    </Setter>
</Style>

添加形状样式选择器

<styleselectors:NodeStyleSelector x:Key="CustomShapeStyleSelector" 
                BilledMsisdnStyle="{StaticResource BilledMsisdnStyle}" 
                BilledImeiStyle="{StaticResource BilledImeiStyle}" />

将ShapeStyleSelector 用作您的RadDiagram。

<telerik:RadDiagram x:Name="Diagram"
                        ShapeStyleSelector="{StaticResource CustomShapeStyleSelecto}"
                        GraphSource="{Binding GraphSource}"/>

【讨论】：