Validating textboxes in WPF. The validtion is checked at LostFocus event of TextBox
public void ValidateTextbox(ref TextBox ctrltxt, string p)
{
int count = 0;
string errormessage=string.Empty;
BindingExpression expression = ctrltxt.GetBindingExpression(TextBox.TextProperty);
expression.UpdateSource();
if (true) // check validation condition or reg expression here
{
ValidationError error = new ValidationError(new ExceptionValidationRule(), expression, errormessage, null);
Validation.MarkInvalid(expression, error);
}
} |
XAML code for the TEXTBOX is as below
<TextBox Name="FieldName" HorizontalAlignment="Stretch"
VerticalAlignment="Stretch"
Text="{Binding Path=DisplayData, ValidatesOnDataErrors=True ,NotifyOnValidationError=True , UpdateSourceTrigger=LostFocus, ValidatesOnExceptions=True}"
Grid.Column="1"
Margin="4,4,4,4" Validation.ErrorTemplate="{StaticResource InputErrorTemplate}" >
</TextBox>
|
InputErrorTemplate is as below
<ControlTemplate x:Key="InputErrorTemplate">
<DockPanel>
<Border Name="validationBorder" BorderBrush="Red" BorderThickness="2" Padding="1" CornerRadius="3">
<Border.Resources>
<Storyboard x:Key="_blink">
<ColorAnimationUsingKeyFrames AutoReverse="True" BeginTime="00:00:00" Storyboard.TargetName="validationBorder" Storyboard.TargetProperty="(Border.BorderBrush).(SolidColorBrush.Color)" RepeatBehavior="00:00:02">
<SplineColorKeyFrame KeyTime="00:00:00.5" Value="#00FF0000"/>
</ColorAnimationUsingKeyFrames>
</Storyboard>
</Border.Resources>
<Border.Triggers>
<EventTrigger RoutedEvent="FrameworkElement.Loaded">
<BeginStoryboard Storyboard="{StaticResource _blink}" />
</EventTrigger>
</Border.Triggers>
<AdornedElementPlaceholder/>
</Border>
</DockPanel>
</ControlTemplate>
|