WPF如何使用INotifyDataErrorInfo在文本框旁边显示错误消息

Question

I am new to WPF and started following the tutorial below.

http://social.technet.microsoft.com/wiki/contents/articles/19490.validating-data-in-wpf-4-5-using-the-inotifyerrordataerror-interface.aspx#Visual_feedback

It is using error template to display the error like below

<Validation.ErrorTemplate>

    <ControlTemplate>

        <StackPanel>

            <!-- Placeholder for the TextBox itself -->

            <AdornedElementPlaceholder x:Name="textBox"/>

            <ItemsControl ItemsSource="{Binding}">

                <ItemsControl.ItemTemplate>

                    <DataTemplate>

                        <TextBlock Text="{Binding ErrorContent}" Foreground="Red"/>

                    </DataTemplate>

                </ItemsControl.ItemTemplate>

            </ItemsControl>

        </StackPanel>

    </ControlTemplate>

</Validation.ErrorTemplate>

I got how to display the error message just below the text box as in the tutorial. However, I wanted to display the error message next to the text box instead of below the text box.

Is there a way to do it? I tried to define a new grid column and tried to set the StackPanel to position at that new grid but it does not work. (Grid.Column does not seems to be valid in there)

Answer 1

You need to adjust ErrorTemplate :

<TextBox Text="{Binding Username, UpdateSourceTrigger=PropertyChanged, ValidatesOnNotifyDataErrors=True}">
    <Validation.ErrorTemplate>
        <ControlTemplate>

            <!-- Align text box and error list horizontally -->
            <StackPanel Orientation="Horizontal">

                <AdornedElementPlaceholder x:Name="textBox"/>
                <ItemsControl ItemsSource="{Binding}">
                    <ItemsControl.ItemTemplate>
                        <DataTemplate>
                            <TextBlock Text="{Binding ErrorContent}" Foreground="Red"/>
                        </DataTemplate>
                    </ItemsControl.ItemTemplate>
                </ItemsControl>
            </StackPanel>
        </ControlTemplate>
    </Validation.ErrorTemplate>
</TextBox>