MVVM:绑定到 ListBox.SelectedItem? [英] MVVM: Binding to ListBox.SelectedItem?

问题描述

如何将视图模型属性绑定到 ListBox.SelectedItem 属性?

How do I bind a view model property to the ListBox.SelectedItem property?

我创建了一个简单的 MVVM 演示来尝试解决这个问题.我的视图模型具有以下属性:

I have created a simple MVVM demo to try to figure this one out. My view model has these properties:

private ObservableCollection<DisneyCharacter> p_DisneyCharacters;
public ObservableCollection<DisneyCharacter> DisneyCharacters
{
    get { return p_DisneyCharacters; }

    set
    {
        p_DisneyCharacters = value;
        base.FirePropertyChangedEvent("DisneyCharacters");
    }
}

private DisneyCharacter p_SelectedItem;
public DisneyCharacter SelectedItem
{
    get { return p_SelectedItem; }

    set
    {
        p_SelectedItem = value;
        base.FirePropertyChangedEvent("SelectedItem");
    }
}

我想将 SelectedItem 属性绑定到列表框中选定的项目.这是列表框的 XAML:

I want to bind the SelectedItem property to the item selected in the list box. Here is the XAML for the list box:

<ListBox ItemTemplate="{StaticResource MasterTemplate}"
         ItemsSource="{Binding Path=DisneyCharacters}" 
         SelectedItem="{Binding Path=Selectedtem, Mode=TwoWay}" 
         HorizontalAlignment="Stretch" />

这是我的问题:当我更改列表框中的选择时，视图模型 SelectedItem 属性没有更新.

Here is my problem: The view model SelectedItem property isn't being updated when I change the selection in the list box.

我做了一个测试，我临时用 SelectedIndex 属性替换了视图模型的 SelectedItem 属性，并将其绑定到 ListBox.SelectedIndex 属性.该属性更新得很好——只是我无法使用的 SelectedItem 属性.

I did a test where I temporarily replaced the view model SelectedItem property with a SelectedIndex property, and I bound that to the ListBox.SelectedIndex property. That property updated fine--it's just the SelectedItem property that I can't get to work.

那么，如何修复 SelectedItem 绑定?感谢您的帮助.

So, how do I fix the SelectedItem binding? Thanks for your help.

推荐答案

嗯，就是这样，就像生命一样重要.在 XAML 中.我绑定到视图模型属性Selectedtem".不幸的是，实际名称是SelectedItem".所以这段代码确实有效——我今天下午早些时候解决了这个问题，然后花了整个下午和整个晚上的时间在网上搜索，然后才发现拼写错误.

Well, there it is, big as life. In the XAML. I am binding to a view model property "Selectedtem". Unfortunately, the actual name is "SelectedItem". So this code actually works--I solved the problem early this afternoon and then spent the rest of the afternoon and all evening scouring the web, before I noticed the spelling error.

我妻子在今天下午 3:00 告诉我，你知道，结果会是一件小事."所以它确实 - 一个丢失的字母I".好吧，至少我现在可以去睡觉了.

My wife told me at 3:00 this afternoon, "You know, it's going to turn out to be something small." And so it did--a missing letter "I". Well, at least I can go to bed now.

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