How to enable a button when a user types into a textbox

Question

What is the simplest way in WPF to enable a Button when the user types something into a TextBox?

Answer 1

IF you were not using Commands, another alternative is using a Converter.

For example, using a generic Int to Bool converter:

  [ValueConversion(typeof(int), typeof(bool))]
  public class IntToBoolConverter : IValueConverter
  {
    #region IValueConverter Members

    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
      try
      {
        return (System.Convert.ToInt32(value) > 0);
      }
      catch (InvalidCastException)
      {
        return DependencyProperty.UnsetValue;
      }
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
      return System.Convert.ToBoolean(value) ? 1 : 0;
    }

    #endregion
  }

Then on the buttons IsEnabled property:

HTH,

Dennis