GridView中的双向数据绑定 [英] Two way data binding in a GridView

问题描述

我们有一个应用程序，使用简单的单向绑定与GridView来显示一些数据。那么现在我们需要允许用户更改一些数据，所以我一直在尝试使用GridView中的两种方式进行数据绑定。到目前为止，一切正常显示，但在GridView中编辑单元格似乎什么都不做。我搞砸了什么？这样的双向数据绑定呢？我应该开始转换所有内容以使用不同的控件，例如可能是DataGrid？

We have an app that uses simple one way binding with a GridView to display some data. Well, now we need to allow the user to change some of that data, so I've been trying to get two way data binding to work in the GridView. So far everything displays correctly, but editing cells in the GridView seems to do nothing at all. What am I messing up? Is two way databinding like this even possible? Should I just start converting everything to use a different control, like maybe a DataGrid?

我写了一个显示我的问题的小测试应用程序。如果你尝试，你会看到属性设置器在初始化后永远不会被调用。

I wrote a tiny test app that shows my problem. If you try it, you'll see that the property setters never get called after their initialization.

Xaml：

Xaml:

    Title="Window1" Height="300" Width="300">
    <Grid>
        <ListView Name="TestList">
            <ListView.View>
                <GridView>
                    <GridViewColumn Header="Strings">
                        <GridViewColumn.CellTemplate>
                            <DataTemplate>
                                <TextBox Text="{Binding Path=String, Mode=TwoWay}"/>
                            </DataTemplate>
                        </GridViewColumn.CellTemplate>
                    </GridViewColumn>
                    <GridViewColumn Header="Bools">
                        <GridViewColumn.CellTemplate>
                            <DataTemplate>
                                <CheckBox IsChecked="{Binding Path=Bool, Mode=TwoWay}"/>
                            </DataTemplate>
                        </GridViewColumn.CellTemplate>
                    </GridViewColumn>
                </GridView>
            </ListView.View>
        </ListView>
    </Grid>
</Window>

这里是相应的代码：

using System.Collections.Generic;
using System.Windows;

namespace GridViewTextbox
{
    public partial class Window1 : Window
    {
        private List<TestRow> _rows = new List<TestRow>();

        public Window1()
        {
            InitializeComponent();

            _rows.Add(new TestRow("a", false));
            _rows.Add(new TestRow("b", true));
            _rows.Add(new TestRow("c", false));

            TestList.ItemsSource = _rows;
            TestList.DataContext = _rows;
        }
    }

    public class TestRow : System.Windows.DependencyObject
    {
        public TestRow(string s, bool b)
        {
            String = s;
            Bool = b;
        }

        public string String
        {
            get { return (string)GetValue(StringProperty); }
            set { SetValue(StringProperty, value); }
        }

        // Using a DependencyProperty as the backing store for String.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty StringProperty =
            DependencyProperty.Register("String", typeof(string), typeof(TestRow), new UIPropertyMetadata(""));


        public bool Bool
        {
            get { return (bool)GetValue(BoolProperty); }
            set { SetValue(BoolProperty, value); }
        }

        // Using a DependencyProperty as the backing store for Bool.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty BoolProperty =
            DependencyProperty.Register("Bool", typeof(bool), typeof(TestRow), new UIPropertyMetadata(false));
    }
}

推荐答案

您使用依赖关系属性，Setters不会被绑定调用，而是直接更改值（使用SetValue或类似的东西）。

When you use Dependency Properties, the Setters will not be called by bindings, instead they change the value directly (using SetValue or something similar).

尝试添加PropertyChangedCallback，并设置一个断点，看看是否从GridView中更改值。

Try adding a PropertyChangedCallback, and set a breakpoint in there to see if the value is changed from the GridView.

public static readonly DependencyProperty BoolProperty =
    DependencyProperty.Register("Bool", typeof(bool), typeof(TestRow), new UIPropertyMetadata(false, OnBoolChanged));
private static void OnBoolChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
{
    //this method will be called everytime Bool changes value
}

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