WPF DataGrid 绑定到列表和子列表

Question

我有一个Bin 对象列表，其中包含Id、Name 和List<int> 属性，我将其加载为ComboBox 的ItemsSource，以及带有List<Part> 的DataGrid具有Id 和Name 属性的对象。

现在我可以通过 ComboBox 选择单个元素。 我想更新 DataGrid 以仅显示第一个 Bin 对象列表中的元素，并且我想显示 Id，而不是 Name。

不幸的是，我没有发现任何关于这个问题的信息。也许我忽略了一些东西。这是我的代码：

MainWindow.xaml

<Window x:Class="DataGridBinding.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:DataGridBinding"
        mc:Ignorable="d"
        Title="MainWindow" Height="200" Width="400">

    <Grid>
        <StackPanel Orientation="Vertical">

            <ComboBox Name="CmbList" Height="23" Width="180" Margin="6">
                <ComboBox.ItemTemplate>
                    <DataTemplate>
                        <TextBlock Text="{Binding Name}" />
                    </DataTemplate>
                </ComboBox.ItemTemplate>
            </ComboBox>

            <DataGrid x:Name="DtgItems" Width="350" Margin="6" 
                      ItemsSource="{Binding}" 
                      SelectedValue="{Binding ElementName=CmbList, Path=SelectedItem.ItemsNr}">
                <DataGrid.Columns>
                    <DataGridTextColumn Binding="{Binding}"/>
                    <DataGridTextColumn Binding="{Binding Id}"/>
                    <DataGridTextColumn Binding="{Binding Name}"/>
                </DataGrid.Columns>
            </DataGrid>

        </StackPanel>
    </Grid>
</Window>

MainWindow.xaml.cs

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace DataGridBinding
{
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            this.InitializeComponent();

            this.CmbList.ItemsSource = new List<Bin>
            {
                new Bin
                {
                    Id = 1,
                    Name = "Object One",
                    ItemsNr = new List<int> { 1, 3, 5, }
                },
                new Bin
                {
                    Id = 2,
                    Name = "Object Two",
                    ItemsNr = new List<int> { 2, 4, 6, }
                },
                new Bin
                {
                    Id = 3,
                    Name = "Object Three",
                    ItemsNr = new List<int> { 7, 8, 9, }
                },
                new Bin
                {
                    Id = 4,
                    Name = "Object Four",
                    ItemsNr = new List<int> { 4, 8 }

                },
            };

            this.DtgItems.DataContext = new List<Part>
            {
                new Part { Id = 1, Name = "One" },
                new Part { Id = 2, Name = "Two" },
                new Part { Id = 3, Name = "Three" },
                new Part { Id = 4, Name = "Four" },
                new Part { Id = 5, Name = "Five" },
                new Part { Id = 6, Name = "Six" },
                new Part { Id = 7, Name = "Seven" },
                new Part { Id = 8, Name = "Eight" },
                new Part { Id = 9, Name = "Nine" },
            };

            this.CmbList.SelectedIndex = 0;
        }
    }

    public class Bin
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public List<int> ItemsNr { get; set; }
    }

    public class Part
    {
        public int Id { get; set; }
        public string Name { get; set; }

    }
}

Answer 1

这是一个工作示例：

<Window x:Class="DataGridBinding.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:DataGridBinding"
        mc:Ignorable="d"
        Title="MainWindow" Height="200" Width="400">

    <Grid>
        <StackPanel Orientation="Vertical">

            <ComboBox Name="CmbList" Height="23" Width="180" Margin="6" SelectionChanged="CmbList_SelectionChanged">
                <ComboBox.ItemTemplate>
                    <DataTemplate>
                        <TextBlock Text="{Binding Name}" />
                    </DataTemplate>
                </ComboBox.ItemTemplate>
            </ComboBox>

            <DataGrid x:Name="DtgItems" Width="350" Margin="6"
                      AutoGenerateColumns="False">
                <DataGrid.Columns>
                    <DataGridTextColumn Header="Id" Binding="{Binding Id}"/>
                    <DataGridTextColumn Header="Name" Binding="{Binding Name}"/>
                </DataGrid.Columns>
            </DataGrid>

        </StackPanel>
    </Grid>
</Window>

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace DataGridBinding
{
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
            CmbList.ItemsSource = Bins;
            DtgItems.ItemsSource = Parts;
        }
        List<Bin> Bins = new List<Bin>
        {
            new Bin
            {
                Id = 1,
                Name = "Object One",
                ItemsNr = new List<int> { 1, 3, 5, }
            },
            new Bin
            {
                Id = 2,
                Name = "Object Two",
                ItemsNr = new List<int> { 2, 4, 6, }
            },
            new Bin
            {
                Id = 3,
                Name = "Object Three",
                ItemsNr = new List<int> { 7, 8, 9, }
            },
            new Bin
            {
                Id = 4,
                Name = "Object Four",
                ItemsNr = new List<int> { 4, 8 }

            },
        };
        List<Part> Parts = new List<Part>
        {
            new Part { Id = 1, Name = "One" },
            new Part { Id = 2, Name = "Two" },
            new Part { Id = 3, Name = "Three" },
            new Part { Id = 4, Name = "Four" },
            new Part { Id = 5, Name = "Five" },
            new Part { Id = 6, Name = "Six" },
            new Part { Id = 7, Name = "Seven" },
            new Part { Id = 8, Name = "Eight" },
            new Part { Id = 9, Name = "Nine" },
        };
        public class Bin
        {
            public int Id { get; set; }
            public string Name { get; set; }
            public List<int> ItemsNr { get; set; }
        }
        public class Part
        {
            public int Id { get; set; }
            public string Name { get; set; }
        }
        private void CmbList_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            DtgItems.ItemsSource = Parts.Where(t => t.Id == ((Bin)CmbList.SelectedItem).Id);
        }
}

这里要注意的是添加的事件处理程序CmbList_SelectionChanged，它在ComboBox 选择更改时触发，它将网格的ItemsSource 属性更新为仅具有匹配Id 的项目。

您使用的是SelectedIndex 属性，它与Id 不同。索引是从零开始的，而 id 不是。

不用说，尽管代码有效，但还有更好的方法来解决这个问题。我建议您查看MVVM pattern 和DataBinding，尽管代码隐藏方法也绝对有效。祝你好运。