xaml 中的代码部分分为头部的错误界面和下侧的展示界面

<Window x:Class="UserDemo3.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="433" Width="545">
    <Grid>
        <DataGrid Name="dGrid" Margin="5,8,5,51" CanUserAddRows="False"  CanUserDeleteRows="True" ItemsSource="{Binding}"    IsReadOnly="False" CellEditEnding="dGrid_CellEditEnding">
            <DataGrid.Resources>
                <Style x:Key="errorStyle" TargetType="{x:Type TextBox}">
                    <Setter Property="Padding" Value="-2"/>
                    <Style.Triggers>
                        <Trigger Property="Validation.HasError" Value="True">
                            <Setter Property="BorderBrush" Value="Red"/>
                            <Setter Property="ToolTip" 
          Value="{Binding RelativeSource={RelativeSource Self},
            Path=(Validation.Errors)[0].ErrorContent}"/>
                        </Trigger>
                    </Style.Triggers>
                </Style> 
            </DataGrid.Resources>
            
                <DataGrid.Columns>
                <DataGridTextColumn Header="Course Name"  Binding="{Binding Name, TargetNullValue=(enter a course name)}"/>
                    
                    
                <DataGridTextColumn Header="Course ID"  EditingElementStyle="{StaticResource errorStyle}"  Binding="{Binding Id, ValidatesOnExceptions=True}"/>
                    
                <DataGridTextColumn Header="Start Date" EditingElementStyle="{StaticResource errorStyle}"  Binding="{Binding StartDate, ValidatesOnExceptions=True}"/>
              
            </DataGrid.Columns>

        </DataGrid>
        <Button Content="Button" Height="23" HorizontalAlignment="Left" Margin="122,360,0,0" Name="button1" VerticalAlignment="Top" Width="75" Click="button1_Click" />
    </Grid>
</Window>

后台的逻辑代码的部分为：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
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;
using System.ComponentModel;
using System.Windows.Controls.Primitives;

namespace UserDemo3
{

    /// <summary>
    /// MainWindow.xaml 的交互逻辑
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
            dGrid.InitializingNewItem += (sender, e) =>
            {
                //Course newCourse = e.NewItem as Course;
                //newCourse.StartDate = newCourse.EndDate = DateTime.Today;
            };

            #region ...
            List<Demo> listdemo = new List<Demo>();
            listdemo = new List<Demo>() { 
                new Demo(){ Id =1,Name=2,StartDate = 3 },
                   new Demo(){ Id =1,Name=2,StartDate = 3 },
                      new Demo(){ Id =1,Name=2,StartDate = 3}
            };
            dGrid.DataContext = listdemo;
            var obj = dGrid.CurrentCell;

            #endregion
        }

        private void dGrid_CellEditEnding(object sender, DataGridCellEditEndingEventArgs e)
        {
            #region ds

            DataGridRow dr = (DataGridRow)dGrid.ItemContainerGenerator.ContainerFromIndex(0); // 在这里进行列
            DataGridCellsPresenter presenter = GetVisualChild<DataGridCellsPresenter>(dr);
            DataGridCell cell = (DataGridCell)presenter.ItemContainerGenerator.ContainerFromIndex(2); //取第0列每行单元格
            cell.Focus();

            //System.Windows.Media.Brush

            #endregion
        }
        //点击事件
        private void button1_Click(object sender, RoutedEventArgs e)
        {

            #region ds
            int i = 0;
            if (i < dGrid.Items.Count)
            {
                DataGridRow dr = (DataGridRow)dGrid.ItemContainerGenerator.ContainerFromIndex(2);// 行
                DataGridCellsPresenter presenter = GetVisualChild<DataGridCellsPresenter>(dr);
                DataGridCell cell = (DataGridCell)presenter.ItemContainerGenerator.ContainerFromIndex(1); //列
                cell.Focus();

                //System.Windows.Media.Brush

            }
            #endregion
        }

        public static T GetVisualChild<T>(Visual parent) where T : Visual
        {
            T child = default(T);
            int numVisuals = VisualTreeHelper.GetChildrenCount(parent);
            for (int i = 0; i < numVisuals; i++)
            {
                Visual v = (Visual)VisualTreeHelper.GetChild(parent, i);
                child = v as T;
                if (child == null)
                {
                    child = GetVisualChild<T>(v);
                }
                if (child != null)
                {
                    break;
                }
            }
            return child;
        }
    }
    public class Demo
    {
        public int Id { get; set; }
        public int Name { get; set; }
        public int StartDate { get; set; }

    }



}

展示出来的效果为：

点击输入的时候如果不是数字的话，就会出现错误，点击按钮的时候会进行聚焦datagreade的当前的光标的位置