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).所以我正在编辑问题.

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

我将一个字符串列表绑定到一个 ListBox，如下所示.但是，当我更改文本框的内容时，它并没有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();
    }

还有 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

每个ListBoxItem的DataContext就是字符串本身，所以你绑定的路径为空(<代码>.).TwoWay 和 OneWayToSource 绑定需要路径，因为您不能只替换当前的 DataContext.因此，您需要将字符串包装在一个将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; }
}

将字符串公开为 StringItem 的列表:

Expose the strings as a list of 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 Value 属性:

<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 还需要实现 INotifyPropertyChanged 以便自动更新绑定.您还应该将列表公开为 ObservableCollection<T> 而不是 List<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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