DataGridTextColumn值不断变回（如果无效）

Question

With ValidatesOnDataErrors=True when I DataGridTextColumn contents invalid value, if I programmingly change the value, it will display the changed value, but until you click into the Column (enter into the edit mode), the value will revert back to the invalid one... Below is a working sample:

XAML:

<Window x:Class="WpfApplication1.Window13"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="Window13" Height="300" Width="300">
<Grid>
    <DataGrid VerticalAlignment="Top" Margin="0,5"  CanUserAddRows="True"  AutoGenerateColumns="False"  VerticalScrollBarVisibility="Auto"  ItemsSource="{Binding Pricelist}" CanUserDeleteRows="True" >
        <DataGrid.Columns>
            <DataGridTextColumn Header="Price" Width="60" Binding="{Binding Price, UpdateSourceTrigger=PropertyChanged, ValidatesOnDataErrors=True}"/>                
        </DataGrid.Columns>
    </DataGrid>
    <Button Content="Correct" Height="23" HorizontalAlignment="Left" Margin="191,226,0,0" Name="button1" VerticalAlignment="Top" Width="75" Click="button1_Click" />
</Grid>

CodeBehind:

using System;
using System.Windows;
using System.Collections.ObjectModel;
using System.ComponentModel;

namespace WpfApplication1
{
    public partial class Window13 : Window
    {
        public Window13()
        {
            InitializeComponent();
            Pricelist = new ObservableCollection<MyProduct>();
            this.DataContext = this;
        }

        public ObservableCollection<MyProduct> Pricelist { get; set; }

        private void button1_Click(object sender, RoutedEventArgs e)
        {
            foreach(var p in Pricelist)
            {
                p.Price = "0";
            }
        }
    }

    public class MyProduct:INotifyPropertyChanged,IDataErrorInfo
    {
        private string _price;
        public string Price
        {
            get
            {
                return _price;
            }
            set
            {
                _price = value;
                this.RaisePropertyChanged("Price");
            }
        }
        public event PropertyChangedEventHandler PropertyChanged;
        protected virtual void OnPropertyChanged(PropertyChangedEventArgs e)
        {
            var handler = this.PropertyChanged;
            if (handler != null)
            {
                handler(this, e);
            }
        }
        protected void RaisePropertyChanged(String propertyName)
        {
            OnPropertyChanged(new PropertyChangedEventArgs(propertyName));
        }
        public string Error
        {
            get
            {
                return this["Price"];
            }
        }
        public string this[string columnName]
        {
            get
            {
                string result = string.Empty;
                switch (columnName)
                {
                    case "Price":
                        {
                            decimal temdecimal = 0.00m;

                            if (string.IsNullOrEmpty(Price) || string.IsNullOrWhiteSpace(Price)
                                || !decimal.TryParse(Price, out temdecimal))
                            {
                                result = "Price is invalid";
                            }
                            break;
                        }
                    default:
                        {
                            break;
                        }
                }
                return result;
            }
        }
    }
}

Reproduce:

Eg: input "ADS" into the Column which is invalid for a number field, and then change it to "1" use a button , it will display 1 in the column, but as soon as you click the cell and enter into the edit mode, the value will change back to ADS again.

Current Workaround:

Just to make it clear, the current workaround I have is to remove ValidatesOnDataErrors=True in the DataGridTextColumn.EditingElementStyle :

<DataGridTextColumn Header="Price" Width="60">
     <DataGridTextColumn.ElementStyle>
          <Style TargetType="TextBlock">
                 <Setter Property="Text" Value="{Binding Price,UpdateSourceTrigger=PropertyChanged, ValidatesOnDataErrors=True}"/>
          </Style>
     </DataGridTextColumn.ElementStyle>
     <DataGridTextColumn.EditingElementStyle>
          <Style TargetType="TextBox">
                 <Setter Property="Text" Value="{Binding Price,UpdateSourceTrigger=PropertyChanged}"/>
          </Style>
     </DataGridTextColumn.EditingElementStyle>
</DataGridTextColumn>

Answer 1

尝试将Mode=TwoWay添加到您的Binding代码中，它对我Mode=TwoWay ！

Binding="{Binding  Price, UpdateSourceTrigger=PropertyChanged, ValidatesOnDataErrors=True,Mode=TwoWay}"