I've implemented the IDataErrorInfo interface, which is working as shown below.
I have not created my ErrorTemplate , which is being used is the .NET standard.
I would like to know if there is somewhere the XAML code of this error template, because my intention is to create my own error template based on it.
I have already searched the MSDN and tried to use the WPF Tree Visualizer, but I did not succeed.
Explaining in detail how to create / change a template is not easy to do here.
I leave two examples that I use:
RedBorderOnError - Applies a red border and shows a tooltip with the error message when hovering over it.
<Style x:Key="RedBorderOnError" TargetType="{x:Type TextBox}">
<Style.Triggers>
<Trigger Property="Validation.HasError" Value="true">
<Setter Property="ToolTip"
Value="{Binding RelativeSource={RelativeSource Self},
Path=(Validation.Errors).CurrentItem.ErrorContent}"/>
</Trigger>
</Style.Triggers>
</Style>
RedTextOnError - Applies the red color to Foreground and shows a tooltip with the error message when you hover over it.
<Style x:Key="RedTextOnError" TargetType="{x:Type TextBox}">
<Setter Property="Validation.ErrorTemplate">
<Setter.Value>
<ControlTemplate>
<DockPanel LastChildFill="True">
<Border BorderBrush="Transparent" BorderThickness="1">
<AdornedElementPlaceholder />
</Border>
</DockPanel>
</ControlTemplate>
</Setter.Value>
</Setter>
<Style.Triggers>
<Trigger Property="Validation.HasError" Value="true">
<Setter Property="ToolTip"
Value="{Binding RelativeSource={RelativeSource Self},
Path=(Validation.Errors).CurrentItem.ErrorContent}"/>
<Setter Property="Foreground" Value="Red"></Setter>
</Trigger>
</Style.Triggers>
</Style>
Assign the Style to the TextBox like this:
<TextBox ........
Style="{StaticResource RedBorderOnError}"
.....
....../>