如何使用TabItem的名称参数在XAML中调用绑定方法？ [英] How can I call a bound method in XAML with the parameter of a TabItem's name?

问题描述

我有一个在XAML中绑定对象的实例。它有一个方法将返回给我一个其他对象的列表（根据属性值我通过这个方法，它将返回所有的对象与该属性值）。

 < ObjectDataProvider ObjectInstance =_ this.DataContextMethodName =GetListByCategoryx：Key =List> 
< ObjectDataProvider.MethodParameters> 
<系统：String> Windows< / System：String> 
< /ObjectDataProvider.MethodParameters> 
< / ObjectDataProvider> 
  

我（最终）希望在带有一些复杂的DataTemplate的选项卡上显示此列表。但不要超越自己。

我想获取应该在TabControl中的特定TabItem上显示的所有对象（具有与TabItem的名称或标题匹配的类别的对象 - 这是在方法）。如何传递我的绑定方法相关的TabItem的标题或名称？

请记住，我需要绑定到此绑定方法的返回值以显示在DataTemplate在TabItem中。我不知道这是否会与问题的答案相关，但我想确保我明确定义它。

解决方案

不幸的是，$ code> ObjectDataProvider的 MethodParameters 不能直接绑定。

您可以通过使用 TwoWay 或 OneWayToSource 绑定。这是一个使用 Directory.GetFiles 替代您的 GetListByCategory 方法的示例：

 < Grid xmlns =http://schemas.microsoft.com/winfx/2006/xaml/presentation
 xmlns：sys =clr -namespace：System; assembly = mscorlib
 xmlns：io =clr-namespace：System.IO; assembly = mscorlib
 xmlns：x =http://schemas.microsoft.com/winfx / 2006 / xaml> 
< Grid.Resources> 
< x：Array x：Key =directoriesType ={x：Type sys：String}> 
< sys：String> C：\< / sys：String> 
< sys：String> C：\Windows\< / sys：String> 
< sys：String> C：\Windows\System32\< / sys：String> 
< / x：Array> 
< ObjectDataProvider x：Key =fileListObjectType ={x：Type io：Directory}MethodName =GetFiles> 
< ObjectDataProvider.MethodParameters> 
<！ - 初始值，这将被下面的Binding消除。 - > 
< sys：String> C：\< / sys：String> 
< /ObjectDataProvider.MethodParameters> 
< / ObjectDataProvider> 
< /Grid.Resources> 
< TabControl ItemsSource ={StaticResource directories}> 
< TabControl.ItemContainerStyle> 
< Style TargetType ={x：Type TabItem}> 
< Setter Property =ContentTemplate> 
< Setter.Value> 
< DataTemplate DataType ={x：Type sys：String}> 
< ListBox ItemsSource ={Binding Source = {StaticResource fileList}}/> 
< / DataTemplate> 
< /Setter.Value> 
< / Setter> 
< / Style> 
< /TabControl.ItemContainerStyle> 
< TabControl.SelectedItem> 
< Binding Source ={StaticResource fileList}
 Path =MethodParameters [0]
 BindsDirectlyToSource =True
 Mode =OneWayToSource/> 
< /TabControl.SelectedItem> 
< / TabControl> 
< / Grid> 
  

TabControl.SelectedItem 绑定到 ObjectDataProvider.MethodParameters [0] 使用OneWayToSource，这样当我们更改选项卡时，方法参数更改为新目录。

I've got an instance of an object bound in XAML. It's got a method that will return to me a list of other objects (based on the property value I pass this method, it will return all the objects with that property value).

<ObjectDataProvider ObjectInstance="_this.DataContext" MethodName="GetListByCategory" x:Key="List">
        <ObjectDataProvider.MethodParameters>
            <System:String>Windows</System:String>
        </ObjectDataProvider.MethodParameters>
    </ObjectDataProvider> 

I (eventually) want to display this list on a tab with some convoluted DataTemplate. But not to get ahead of myself.

I want to get all the objects that should be displayed on a particular TabItem inside a TabControl (ones that have a category matching the TabItem's name or header - this is done in the method). How do I pass my bound method the relevant TabItem's header or name?

Bear in mind that I need to bind to the return value of this bound method to display in a DataTemplate in the TabItem. I don't know if that would necessarily be relevant to the answer of the problem but I want to make sure that I'm clear in defining it.

解决方案

Unfortunately the MethodParameters of an ObjectDataProvider can't be bound directly.

You can get around this by using a TwoWay or OneWayToSource binding. Here's an example that uses Directory.GetFiles as a substitute for your GetListByCategory method:

<Grid xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:sys="clr-namespace:System;assembly=mscorlib"
      xmlns:io="clr-namespace:System.IO;assembly=mscorlib"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <Grid.Resources>
        <x:Array x:Key="directories" Type="{x:Type sys:String}">
            <sys:String>C:\</sys:String>
            <sys:String>C:\Windows\</sys:String>
            <sys:String>C:\Windows\System32\</sys:String>
        </x:Array>
        <ObjectDataProvider x:Key="fileList" ObjectType="{x:Type io:Directory}" MethodName="GetFiles">
            <ObjectDataProvider.MethodParameters>
                <!-- Initial value, this will get wiped out by the Binding below. -->
                <sys:String>C:\</sys:String>
            </ObjectDataProvider.MethodParameters>
        </ObjectDataProvider>
    </Grid.Resources>
    <TabControl ItemsSource="{StaticResource directories}">
        <TabControl.ItemContainerStyle>
            <Style TargetType="{x:Type TabItem}">
                <Setter Property="ContentTemplate">
                    <Setter.Value>
                        <DataTemplate DataType="{x:Type sys:String}">
                            <ListBox ItemsSource="{Binding Source={StaticResource fileList}}"/>
                        </DataTemplate>
                    </Setter.Value>
                </Setter>
            </Style>
        </TabControl.ItemContainerStyle>
        <TabControl.SelectedItem>
            <Binding Source="{StaticResource fileList}"    
                     Path="MethodParameters[0]"
                     BindsDirectlyToSource="True"  
                     Mode="OneWayToSource"/>
        </TabControl.SelectedItem>
    </TabControl>
</Grid>

The TabControl.SelectedItem is bound to the ObjectDataProvider.MethodParameters[0] using OneWayToSource, so that when we change tabs, the method parameter changes to the new directory.

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