DataGrid 动态绑定数据时出现错误

点击add按钮时，新增到第二个后会出现这个错误。下面是示例代码： XAML页面

<Window x:Class="WpfApp1.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:WpfApp1"
         xmlns:pu="clr-namespace:Panuon.WPF.UI;assembly=Panuon.WPF.UI" 
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="auto"></RowDefinition>
            <RowDefinition></RowDefinition>
        </Grid.RowDefinitions>
        <StackPanel Orientation="Horizontal">
            <TextBox 
                Width="150" 
                Height="30" 
                Margin="5"
                Name="TxtName"
                pu:TextBoxHelper.Watermark="请输入姓名"/>
            <TextBox 
                Width="150" 
                Height="30" 
                Margin="5"
                Name="TxtAge"
                pu:TextBoxHelper.Watermark="年龄"/>
            <Button Content="add"
                    Width="100"
                    Click="Button_Click"/>
        </StackPanel>
        <DataGrid 
            Grid.Row="1" 
            Name="DgData"
            AutoGenerateColumns="False"
            CanUserAddRows="False"
            IsReadOnly="True"
            CanUserResizeRows="False"
            CanUserReorderColumns="False"
            SelectionMode="Extended"
            SelectionUnit="Cell"
            ScrollViewer.VerticalScrollBarVisibility="Visible"
            pu:DataGridHelper.AutoScrollIntoView="True"
            pu:DataGridHelper.ColumnHeaderHorizontalContentAlignment="Center"
            pu:DataGridHelper.MaxRowHeight="30">
            <DataGrid.CellStyle>
                <Style TargetType="DataGridCell" BasedOn="{StaticResource {x:Type DataGridCell}}">
                    <Setter Property="HorizontalContentAlignment" Value="Center"></Setter>
                    <Setter Property="VerticalContentAlignment" Value="Center"></Setter>
                    <Setter Property="FontSize" Value="14"></Setter>
                </Style>
            </DataGrid.CellStyle>
            <DataGrid.Columns>
                <DataGridTextColumn 
                    Width="*" 
                    Header="姓名" 
                    Binding="{Binding Name}"/>

                <DataGridTextColumn 
                    Width="*" 
                    Header="年龄" 
                    Binding="{Binding Age}"/>
            </DataGrid.Columns>
        </DataGrid>
    </Grid>
</Window>

后端cs页面

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

namespace WpfApp1
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        private List<Student> _list = new();

        private void Button_Click(object sender, RoutedEventArgs e)
        {
            _list.Add(new Student
            {
                Id = Guid.NewGuid().ToString(),
                Name = TxtName.Text.Trim(),
                Age = Convert.ToInt32(TxtAge.Text.Trim())
            });
            DgData.ItemsSource = null;
            DgData.ItemsSource = _list;
        }

        public class Student
        {
            public string Id { get; set; }
            public string Name { get; set; }
            public int Age { get; set; }
        }
    }
}

Panuon / Panuon.WPF.UI

DataGrid 动态绑定数据时出现错误 #171