绑定ContentTemplateSelector属性，但将DataContext传递给模板 [英] Bind property for ContentTemplateSelector but pass DataContext to template

问题描述

我试图将一个 ContentPresenter 绑定到一个对象，该对象将根据一些属性来选择要显示的模板，其中模板是绑定对象上的一种视图。

但是，当我设置如下所示的绑定时，我将绑定属性作为 DataContext 的我的 DataTemplate s，而不是属性的所有者。如何解决这个问题？

谢谢！

基础对象看起来像这样（我已经剪掉了除了相关的属性之外）：

  public class ApplicationInterface：BaseBusinessObject，
 IState，INotifyPropertyChanged 
 {
 public Type CurrentPage 
 {
 get 
 {
 return（Type）_properties [CurrentPage]。 
} 
 set 
 {
 _properties [CurrentPage]。 
} 
} 
} 
  

然后我试图绑定到 CurrentPage 属性在XAML喜欢这样：

 < ContentPresenter Content = {Binding CurrentPage}
 ContentTemplateSelector = {StaticResource ResourceKey = PageTemplateSelector}/> 
  

执行 DataTemplateSelector ：

  public class PageTemplateSelector：DataTemplateSelector 
 {
 public override DataTemplate SelectTemplate（object item，
 DependencyObject container）
 {
 FrameworkElement element = container as FrameworkElement; 
 
 if（element ！= null&& item！= null&& item是Type）
 {
键入t =项作为类型; 
 if（t == typeof（Home））
返回element.FindResource（homeTemplate）作为DataTemplate; 
 else if（t == typeof（Profi leEdit））
返回element.FindResource（profileTemplate）作为DataTemplate; 
 else if（t == typeof（WBI））
返回element.FindResource（wbiTemplate）作为DataTemplate; 
 else if（t == typeof（PC））
返回element.FindResource（pcTemplate）作为DataTemplate; 
} 
返回null; 
} 
} 
  

最后， DataTemplate s：

 < DataTemplate x：Key =homeTemplate> 
< pages：Home DataContext ={Binding}/> 
< / DataTemplate> 
< DataTemplate x：Key =profileTemplate> 
< pages：ProfileEdit DataContext ={Binding}/> 
< / DataTemplate> 
< DataTemplate x：Key =wbiTemplate> 
< pages：WBI DataContext ={Binding}/> 
< / DataTemplate> 
< DataTemplate x：Key =pcTemplate> 
< pages：PC DataContext ={Binding}/> 
< / DataTemplate> 
  

解决方案

我最终命名了我的窗口，然后绑定到它的DataContext。所以基本上我只需要将模板绑定更改为：

 < DataTemplate x：Key =homeTemplate> 
< pages：Home DataContext ={Binding ElementName = mainWindow，Path = DataContext}/> 
< / DataTemplate> 
  

我选择了这个而不是修改我的业务对象，因为该视图是纯粹的UI构造。 p>

I am trying to bind a ContentPresenter to an object which will select a template to display based on some property where the template is a sort of view on the bound object.

However, when I set up the binding as seen below, I wind up with the bound property as the DataContext of my DataTemplates, not the owner of the property. How can I fix this?

Thanks!

The base object looks like this (I've cut out all but the relevant property):

public class ApplicationInterface : BaseBusinessObject, 
    IState, INotifyPropertyChanged
{
    public Type CurrentPage
    {
        get
        {
            return (Type)_properties["CurrentPage"].Value;
        }
        set
        {
            _properties["CurrentPage"].Value = value;
        }
    }
}

I then am trying to bind to CurrentPage property in XAML like so:

<ContentPresenter Content="{Binding CurrentPage}" 
    ContentTemplateSelector={StaticResource ResourceKey=PageTemplateSelector}"/>

The implementation of the DataTemplateSelector:

public class PageTemplateSelector : DataTemplateSelector
{
    public override DataTemplate SelectTemplate(object item, 
        DependencyObject container)
    {
        FrameworkElement element = container as FrameworkElement;

        if (element != null && item != null && item is Type)
        {
            Type t = item as Type;
            if (t == typeof(Home))
                return element.FindResource("homeTemplate") as DataTemplate;
            else if (t == typeof(ProfileEdit))
                return element.FindResource("profileTemplate") as DataTemplate;
            else if (t == typeof(WBI))
                return element.FindResource("wbiTemplate") as DataTemplate;
            else if (t == typeof(PC))
                return element.FindResource("pcTemplate") as DataTemplate;
        }
        return null;
    }
}

And finally the DataTemplates:

    <DataTemplate x:Key="homeTemplate">
        <pages:Home DataContext="{Binding}"/>
    </DataTemplate>
    <DataTemplate x:Key="profileTemplate">
        <pages:ProfileEdit DataContext="{Binding}"/>
    </DataTemplate>
    <DataTemplate x:Key="wbiTemplate">
        <pages:WBI DataContext="{Binding}"/>
    </DataTemplate>
    <DataTemplate x:Key="pcTemplate">
        <pages:PC DataContext="{Binding}"/>
    </DataTemplate>

解决方案

I ended up naming my window, then binding to the DataContext of it. So basically all I had to do was change the template bindings to:

<DataTemplate x:Key="homeTemplate">
    <pages:Home DataContext="{Binding ElementName=mainWindow, Path=DataContext}"/>
</DataTemplate>

I opted for this rather than alter my business objects since the view is a purely UI construct.

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