Validation in wpf?

Question

WPF

How to make it so that you can't enter numbers in a textbox

Answer 1

Handle the TextChanged event like so:

private void textBox_TextChanged(object sender, TextChangedEventArgs e)
{
  var index = textBox.CaretIndex;
  textBox.Text = Regex.Replace(textBox.Text, @"\d", "");
  textBox.CaretIndex = index;	
}

Answer 2

public class OnlyTextValidationRule : ValidationRule
{
    public override ValidationResult Validate(object value, System.Globalization.CultureInfo cultureInfo)
    {
        bool noNumbers = Regex.Matches("^([^0-9]*)$",value.ToString()).Count > 0;
        return new ValidationResult(noNumbers, "Value contains numbers");
    }
}

<Window.Resources>
    <local:OnlyTextValidationRule x:Key="NoNumberValidate"/>
</Window.Resources>

<TextBox Text={Binding Value, ValidationRules={StaticResource NoNumberValidate}}/>