<Grid x:Name="gridDetailPerson" Background="White">
    <Grid.RowDefinitions>
        <RowDefinition Height="Auto"></RowDefinition>
        <RowDefinition Height="Auto"></RowDefinition>
    </Grid.RowDefinitions>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="100"></ColumnDefinition>
        <ColumnDefinition Width="*"></ColumnDefinition>
        <ColumnDefinition Width="100"></ColumnDefinition>
    </Grid.ColumnDefinitions>
    <TextBlock Grid.Row="0" Grid.Column="0" Margin="7" Text="姓名"></TextBlock>
    <TextBox Grid.Row="0" Grid.Column="1" Margin="5" Text="{Binding Username}"></TextBox>
        
    <TextBlock Grid.Row="1" Grid.Column="0" Margin="7" Text="年龄"></TextBlock>
    <TextBox Grid.Row="1" Grid.Column="1" Margin="5" Text="{Binding Age,Mode=TwoWay,ValidatesOnExceptions=True}"></TextBox>
</Grid>

int _age;   //范围
/// <summary>
/// 年龄
/// </summary>
public int Age
{
    get { return _age; }
    set
    {
        if (value < 0) throw new ArgumentException("不能小于0");
        _age = value;
    }
}

<Grid x:Name="gridDetailPerson" Background="White" BindingValidationError="gridDetailPerson_BindingValidationError">
    <Grid.RowDefinitions>
        <RowDefinition Height="Auto"></RowDefinition>
        <RowDefinition Height="Auto"></RowDefinition>
        <RowDefinition Height="Auto"></RowDefinition>
        <RowDefinition Height="Auto"></RowDefinition>
    </Grid.RowDefinitions>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="100"></ColumnDefinition>
        <ColumnDefinition Width="*"></ColumnDefinition>
        <ColumnDefinition Width="100"></ColumnDefinition>
    </Grid.ColumnDefinitions>
    <TextBlock Grid.Row="0" Grid.Column="0" Margin="7" Text="姓名"></TextBlock>
    <TextBox Grid.Row="0" Grid.Column="1" Margin="5" Text="{Binding Username}"></TextBox>

    <TextBlock Grid.Row="1" Grid.Column="0" Margin="7" Text="年龄"></TextBlock>
    <TextBox Grid.Row="1" Grid.Column="1" Margin="5" Name="txtAge"
             Text="{Binding Age,Mode=TwoWay,ValidatesOnExceptions=True, NotifyOnValidationError=True}"></TextBox>
    
    <TextBlock Grid.Row="3" Grid.Column="0" Grid.ColumnSpan="2" Margin="7"
                Name="txtBlkTip" Text="" Foreground="Red"></TextBlock>
</Grid>

using System.Windows.Controls;

using SL3ValidationYlbtechApp.Access;
namespace SL3ValidationYlbtechApp.DataBinding.BindingADataObjects.Validation
{
    public partial class NotifyOnValidationError : UserControl
    {
        public NotifyOnValidationError()
        {
            InitializeComponent();
            gridDetailPerson.DataContext = Person.GetModel();
        }

        private void gridDetailPerson_BindingValidationError(object sender, ValidationErrorEventArgs e)
        {
            //显示错误
            txtBlkTip.Text = e.Error.Exception.Message;
            txtBlkTip.Text += "\n存储值：" + ((Person)gridDetailPerson.DataContext).Age;

            //建议用户再试一次
            txtAge.Focus();
        }
    }
}