绑定到List< string>时，如何使ListBox可编辑 [英] How to make ListBox editable when bound to a List<string>?

问题描述

编辑：基本问题是将List绑定到ListBox（或任何其他控件）。所以我正在编辑这个问题。

Edit: The basic problem is binding a List to ListBox(or any other control). So I am editing the question.

我将列表框绑定到ListBox，如下所示。但是，当我更改文本框的内容时，它不会更改源列表中的字符串。为什么？

I bound a list of string to a ListBox as below. However when I change the contents of the textbox it is not changing the string in the source list.Why?

  public partial class MainWindow : Window
{
    List<string> _nameList = null;

    public List<string> NameList
    {
        get
        {
            if (_nameList == null)
            {
                _nameList = new List<string>();
            }
            return _nameList;
        }
        set
        {
            _nameList = value;
        }
    }
    public MainWindow()
    {
        NameList.Add("test1");
        NameList.Add("test2");
        InitializeComponent();
    }

而XAML

 <ListBox Grid.Row="0" Grid.Column="0" DataContext="{Binding ElementName=main}" ItemsSource="{Binding NameList}">
        <ListBox.ItemTemplate>
            <DataTemplate>
                <TextBox Text="{Binding .,Mode=OneWayToSource ,  UpdateSourceTrigger=PropertyChanged}"/>
            </DataTemplate>
        </ListBox.ItemTemplate>
    </ListBox>

推荐答案

DataContext ListBoxItem 的c $ c>是字符串本身，因此绑定的路径为空（。）。 TwoWay 和 OneWayToSource 绑定需要路径，因为您不能仅仅替换当前的 DataContext 。因此，您需要将字符串包装在将该字符串作为属性公开的对象中：

The DataContext of each ListBoxItem is the string itself, so the path of your binding is empty (.). TwoWay and OneWayToSource bindings require a path, since you can't just replace the current DataContext. So you need to wrap your string in an object that exposes the string as a property:

public class StringItem
{
    public string Value { get; set; }
}

将字符串作为 StringItem ：

public partial class MainWindow : Window
{
    List<StringItem> _nameList = null;

    public List<StringItem> NameList
    {
        get
        {
            if (_nameList == null)
            {
                _nameList = new List<StringItem>();
            }
            return _nameList;
        }
        set
        {
            _nameList = value;
        }
    }
    public MainWindow()
    {
        NameList.Add(new StringItem { Value = "test1" });
        NameList.Add(new StringItem { Value = "test2" });
        InitializeComponent();
    }

并绑定到值 property：

And bind to the Value property:

<ListBox Grid.Row="0" Grid.Column="0" DataContext="{Binding ElementName=main}" ItemsSource="{Binding NameList}">
    <ListBox.ItemTemplate>
        <DataTemplate>
            <TextBox Text="{Binding Value, UpdateSourceTrigger=PropertyChanged}"/>
        </DataTemplate>
    </ListBox.ItemTemplate>
</ListBox>

请注意， StringItem 也需要实现 INotifyPropertyChanged ，以便绑定自动更新。您还应该将列表公开为 ObservableCollection< T> 而不是列表< T>

Note that StringItem will also need to implement INotifyPropertyChanged so that bindings are automatically updated. You should also expose the list as an ObservableCollection<T> rather than a List<T>

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