我怎样才能绑定在一个DataTemplate一个ObservableCollection到文本框？ [英] How can I bind an ObservableCollection to TextBoxes in a DataTemplate?

问题描述

我想成功的双向一个ObservableCollection到文本框绑定在一个DataTemplate。我可以得到的数据才能正常显示，但我无法通过UI更改列表数据。我有一个名为模型模型类，它包含一个名为'名单​​'一个ObservableCollection。这个类实现INotifyPropertyChanged接口。下面是外壳的XAML。在DataContext为窗口1的网格设置为theGrid.DataContext =模式

I am trying to successfully TwoWay bind an ObservableCollection to TextBoxes in a DataTemplate. I can get the data to display properly, but I am unable to change the list data through the UI. I have a Model class named 'model' which contains an ObservableCollection named 'List'. The class implements the INotifyPropertyChanged interface. Here is the xaml for the shell. The DataContext for Window1's grid is set to "theGrid.DataContext=model"

<Window x:Class="BindThat.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:BindThat"
Title="Window1" Height="300" Width="300">
<StackPanel x:Name="theGrid">
    <GroupBox BorderBrush="LightGreen">
        <GroupBox.Header>
            <TextBlock Text="Group" />
        </GroupBox.Header>
        <ItemsControl ItemsSource="{Binding Path=List}">
            <ItemsControl.ItemTemplate>
                <DataTemplate>
                    <TextBox Text="{Binding Path=., Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" />
                </DataTemplate>
            </ItemsControl.ItemTemplate>
        </ItemsControl>
    </GroupBox> 
</StackPanel>

这是code为模型类：

This is the code for the Model class:

class Model : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    private void NotifyPropertyChanged(string name)
    {
        if (PropertyChanged != null)
            PropertyChanged(this, new PropertyChangedEventArgs(name));
    }

    private ObservableCollection<string> _list = new ObservableCollection<string>();
    public ObservableCollection<string> List
    {
        get { return _list; }
        set 
        { 
            _list = value;
            NotifyPropertyChanged("List");
        }
    }

    public Model()
    {
        List.Add("why");
        List.Add("not");
        List.Add("these?");
    }
}

谁能告知，如果我要对这个正确的方式？

Could anyone advise if I am going about this the correct way?

推荐答案

您需要一个属性来绑定两个方式，所以字符串不是好这一点。

You need a property to bind two way, so string is not good for this.

包装在一个String对象，像这样的：

Wrap it in a string object, like this:

public class Model
{
    public ObservableCollection<StringObject> List { get; private set; }
    public Model()
    {
        List = new ObservableCollection<StringObject>
                   {
                       new StringObject {Value = "why"},
                       new StringObject {Value = "not"},
                       new StringObject {Value = "these"},
                   };
    }
}

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

和绑定到Value属性，而不是。

and bind to Value property instead of "."

此外，您不需要通知观察到的集合的改变，所以直到你的模型有其自身的一些其他propertis，它并不需要有INotifyPropertyChange。如果你希望你的ItemsControl反应在个人StringObjects变化，那么你应该增加INotifyPropertyChanged的一个StringObject。

Also, you don't need to notify of a change in observable collection, so until your model has some other propertis of its own, it does not need to have INotifyPropertyChange. If you want your ItemsControl react to changes in the individual StringObjects, then you should add INotifyPropertyChanged to a StringObject.

和再次，双向绑定是默认的，所以你只需要

And yet again, two way binding is default, so you need only

<TextBox Text="{Binding Path=Value}" />

在你的绑定。

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