WPF：从DataGrid.RowDetailsTemplate

Question

我有主DataGrid用于显示文档列表。 此MainGrid DataGrid.RowDetailsTemplate中指定了XAML。

此DataGrid.RowDetailsTemplate包含一个（内部或嵌套）DataGrid s。

因此MainGrid的每一行都包含内部DataGrid.RowDetailsTemplate的{​​{1}}。

我需要获取仅具有DataGrid引用的所有内部（嵌套）DataGrid的列表。 我已经尝试过Visual / Logil Tree助手，但两者都没有为GetChildren调用返回任何内容......

从MainGrid获取嵌套DataGrid的方式是什么？

Repro步骤： 1）创建Windows桌面 - ＆gt; Visual Studio 2013或更高版本中的WPF应用程序（空） 2）使用下面的代码示例：

MainWindow.xaml

DataGrid.RowDetails

MainWindow.xaml.cs

<Window x:Class="ExampleNestedGrid.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525">
    <Grid>

        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>

        <ToolBar Grid.Row="0" Header="Action:">
            <Button x:Name="RefreshBtn" Command="{Binding RefreshCommand}">Refresh</Button>
        </ToolBar>

        <DataGrid x:Name="MainGrid" ItemsSource="{Binding Documents}" AutoGenerateColumns="False" Grid.Row="1">
            <DataGrid.Columns>
                <DataGridTextColumn Binding="{Binding Name, Mode=OneWay}" Width="*"/>
                <DataGridTextColumn Binding="{Binding Number, Mode=OneWay}" Width="*"/>
            </DataGrid.Columns>

            <DataGrid.RowDetailsTemplate>
                <DataTemplate>
                    <Grid>
                        <DataGrid x:Name="NestedGrid" ItemsSource="{Binding LinkedEmployees}" AutoGenerateColumns="False">
                            <DataGrid.Columns>
                                <DataGridTextColumn Binding="{Binding Id, Mode=OneWay}" Width="150"/>
                                <DataGridTextColumn Binding="{Binding Name, Mode=OneWay}" Width="150"/>
                                <DataGridTextColumn Binding="{Binding Status, Mode=OneWay}" Width="150"/>
                            </DataGrid.Columns>
                        </DataGrid>
                    </Grid>
                </DataTemplate>
            </DataGrid.RowDetailsTemplate>
        </DataGrid>
    </Grid>
</Window>

RefreshCommand.cs

using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Runtime.CompilerServices;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;

namespace ExampleNestedGrid
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();

            DataContext = new DisplayViewModel(MainGrid);
        }
    }

    public class DisplayViewModel : PropertyBase
    {
        private DataGrid MainGrid;

        public DisplayViewModel(DataGrid MainGrid) 
        {
            this.MainGrid = MainGrid;

            Documents = new ObservableCollection<Document>();
            LinkedEmployee empl1 = new LinkedEmployee("1", "Ben");
            LinkedEmployee empl2 = new LinkedEmployee("2", "John");

            Document doc = new Document("first", "111");
            doc.LinkedEmployees.Add(empl1);
            doc.LinkedEmployees.Add(empl2);

            Documents.Add(doc);

            RefreshCommand = new RefreshCommand(Documents, MainGrid);
        }

        public ObservableCollection<Document> Documents { get; set; }
        public ICommand RefreshCommand { get; set; }
    }

    public sealed class LinkedEmployee : PropertyBase
    {
        public LinkedEmployee(string id, string name)
        {
            _id = id;
            _name = name;
        }

        public void Update(string name)
        {
            Name = name;
        }

        private string _id;
        private string _name;
        private bool _status;

        public bool Status 
        {
            get { return _status; }
            set
            {
                _status = value;
                OnPropertyChanged();
            }
        }

        public string Id
        {
            get { return _id; }
            set
            {
                _id = value;
                OnPropertyChanged();
            }
        }

        public string Name
        {
            get { return _name; }
            set
            {
                _name = value;
                OnPropertyChanged();
            }
        }
    }

    public class Document : PropertyBase
    {
        public Document(string name, string number)
        {
            _name = name;
            _number = number;

            LinkedEmployees = new ObservableCollection<LinkedEmployee>();
        }

        public void Update(string number)
        {
            Number = number;
        }

        private string _name;
        private string _number;

        public virtual string Name
        {
            get { return _name; }
            set
            {
                _name = value;
                OnPropertyChanged();
            }
        }

        public virtual string Number
        {
            get { return _number; }
            set
            {
                _number = value;
                OnPropertyChanged();
            }
        }

        public ObservableCollection<LinkedEmployee> LinkedEmployees { get; set; }
    }

    public abstract class PropertyBase : INotifyPropertyChanged
    {
        #region public properties
        public event PropertyChangedEventHandler PropertyChanged;
        #endregion

        #region protected methods
        protected void OnPropertyChanged([CallerMemberName]string caller = null)
        {
            if (PropertyChanged != null)
                PropertyChanged.Invoke(this, new PropertyChangedEventArgs(caller));
        }
        #endregion
    }
}

3）开始申请。单击第一行。行详细信息应该扩展。

4）按第一列排序主行

5）按第二列排序行详细信息

6）点击刷新按钮

7）检查分类指示消失。

8）检查是否没有出现应该触发找到的嵌套数据网格的消息框。

Answer 1

您只能获得RowDetailsTemplate中当前可见元素的引用。试试这个：

private void Button_Click(object sender, RoutedEventArgs e)
{
    var childGrids = FindVisualChildren<DataGrid>(MainGrid);
    foreach (DataGrid childGrid in childGrids)
    {
        //...
    }
}

private static IEnumerable<T> FindVisualChildren<T>(DependencyObject depObj) where T : DependencyObject
{
    if (depObj != null)
    {
        for (int i = 0; i < VisualTreeHelper.GetChildrenCount(depObj); i++)
        {
            DependencyObject child = VisualTreeHelper.GetChild(depObj, i);
            if (child != null && child is T)
            {
                yield return (T)child;
            }

            foreach (T childOfChild in FindVisualChildren<T>(child))
            {
                yield return childOfChild;
            }
        }
    }
}

修改：如果您重置UpdateLayout()，请调用DataGrid的{​​{1}}方法。如果我在父ItemsSource中选择一行并单击“刷新”按钮，则此命令的Execute方法的实现对我有用：

DataGrid