在Validation.HasError上以WPF MVVM方式将焦点设置为UI控件

问题：Validation.HasError通过INotifyDataErrorInfo实现自动突出显示有错误的控件

我的问题是，当特定控件出错时，我需要将焦点设置在该控件上

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如何做到这一点？

我已经阅读了Stackoverflow和其他网站上的几篇文章，最后我希望解决这个问题

   <Style TargetType="TextBox" >
                        <Setter Property="OverridesDefaultStyle" Value="false"/>
                        <Setter Property="VerticalAlignment" Value="Center"/>
                        <Setter Property="HorizontalAlignment" Value="Left"/>
                        <Setter Property="Margin" Value="5,3" />
                        <Style.Triggers>
                            <Trigger Property="Validation.HasError" Value="True">
                                <Setter Property="FocusManager.FocusedElement" Value="{Binding RelativeSource={RelativeSource Self}}"/>
                            </Trigger>
                        </Style.Triggers>
                    </Style>

设置FocusedElement成功了。：）

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这也可以用于通过DataTrigger而不是简单的触发器在ViewModel中使用布尔属性设置焦点。

Wpf MVVM使用FocusExtension行为

 public static class FocusExtension
{
    public static bool GetIsFocused(DependencyObject obj)
    {
        return (bool)obj.GetValue(IsFocusedProperty);
    }
    public static void SetIsFocused(DependencyObject obj, bool value)
    {
        obj.SetValue(IsFocusedProperty, value);
    }
    public static readonly DependencyProperty IsFocusedProperty =
           DependencyProperty.RegisterAttached(
                 "IsFocused", typeof(bool), typeof(FocusExtension),
                 new UIPropertyMetadata(false, OnIsFocusedPropertyChanged));
    private static void OnIsFocusedPropertyChanged(DependencyObject d,
           DependencyPropertyChangedEventArgs e)
    {   
        var uie = (UIElement)d;

        if ((bool)e.NewValue)
        {
            uie.Focus();

        }


    }
}

Xaml代码

            <TextBox
                    behavior:FocusExtension.IsFocused="{Binding NameFocus}"
                    Text="{Binding Customer_Name,Mode=TwoWay, UpdateSourceTrigger=PropertyChanged }"
                    x:Name="txtname" 
                    CharacterCasing="Upper"
                    Grid.Column="3"
                    Grid.Row="1"
                    TextWrapping="Wrap" 
                    BorderThickness="1,1,1,0.5"
                    >

            </TextBox>

设置加载事件

NameFocus=true

NameFocus=true