c# - WPF- 验证错误事件不会触发

Question

我想我已经阅读了所有相关文章，但没有一篇有帮助..

我试图通过错误状态启用/禁用 datagrid 的保存按钮 - 但没有成功。

这是我的代码:

承包商:

AddHandler(Validation.ErrorEvent, new RoutedEventHandler(OnErrorEvent));

XAML:

    <Page
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
  xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
  xmlns:col="clr-namespace:System.Collections;assembly=mscorlib"
 xmlns:local="clr-namespace:Metsuka_APP" x:Class="Metsuka_APP.MichlolimManagment" 
  mc:Ignorable="d" 
  d:DesignHeight="500" d:DesignWidth="500"
Title="MichlolimManagment"
x:Name="Michlolim_Managment" Validation.Error="Michlolim_Managment_Error">
<Page.Resources>

<DataGrid x:Name="AGAFIMDataGrid" VerticalAlignment="Center" RowEditEnding="rowEditEnding" Margin="10" FlowDirection="RightToLeft" Height="340"
    AutoGenerateColumns="False" EnableRowVirtualization="True"
                  ItemsSource="{Binding Source={StaticResource aGAFIMViewSource}}"   Grid.Row="1"
                  RowDetailsVisibilityMode="VisibleWhenSelected"
                 ScrollViewer.CanContentScroll="True"
                 ScrollViewer.VerticalScrollBarVisibility="Auto" 
                 HorizontalGridLinesBrush="Silver"
                 VerticalGridLinesBrush="Silver">
            <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="Background" Value="Red"/>
                            <Setter Property="ToolTip" 
          Value="{Binding RelativeSource={RelativeSource Self},
            Path=(Validation.Errors)[0].ErrorContent}"/>
                        </Trigger>
                    </Style.Triggers>
                </Style>
            </DataGrid.Resources>
            <DataGrid.Columns>
                <DataGridTextColumn x:Name="agaf_nameColumn"  Header="name" Width="*">
                    <DataGridTextColumn.Binding>
                        <Binding Path="agaf_name" NotifyOnValidationError="True" >
                            <Binding.ValidationRules>
                            <local:MichlolimValidationRule ValidationStep="UpdatedValue"/>
                        </Binding.ValidationRules>
                    </Binding>
                        </DataGridTextColumn.Binding>
                </DataGridTextColumn>
            </DataGrid.Columns>
            <DataGrid.RowValidationErrorTemplate>
                <ControlTemplate>
                    <Grid Margin="0,-2,0,-2"
            ToolTip="{Binding RelativeSource={RelativeSource
            FindAncestor, AncestorType={x:Type DataGridRow}},
            Path=(Validation.Errors)[0].ErrorContent}">
                        <Ellipse StrokeThickness="0" Fill="Red" 
              Width="{TemplateBinding FontSize}" 
              Height="{TemplateBinding FontSize}" />
                        <TextBlock Text="!" FontSize="{TemplateBinding FontSize}" 
              FontWeight="Bold" Foreground="White" 
              HorizontalAlignment="Center"  />
                    </Grid>
                </ControlTemplate>
            </DataGrid.RowValidationErrorTemplate>
        </DataGrid>

代码隐藏:

    private int errorCount;

    private void OnErrorEvent(object sender, RoutedEventArgs e)
    {
        var validationEventArgs = e as ValidationErrorEventArgs;
        if (validationEventArgs == null)
            throw new Exception("Unexpected event args");
        switch (validationEventArgs.Action)
        {
            case ValidationErrorEventAction.Added:
                {
                    errorCount++; break;
                }
            case ValidationErrorEventAction.Removed:
                {
                    errorCount--; break;
                }
            default:
                {
                    throw new Exception("Unknown action");
                }
        }
        btnSavePop.IsEnabled = errorCount == 0;
    }

但是 "OnErrorEvent" 永远不会触发 - 知道为什么吗？

Answer 1

你需要设置NotifyOnValidationError="True"在您的绑定(bind)上 - 否则，不会引发该事件。对于 MVVM 错误处理方法，我建议使用 IDataErrorInfo 或 INotifyDataErrorInfo 接口(interface)。