Question

Is it possible to define type converter for binding inline (without resource)?

Something like this:

   <Button Visibility="{Binding ElementName=checkBox, Path=IsChecked, Converter={new BooleanToVisibilityConverter}" />

Answer 1

You can create and expose your converter through a custom MarkupExtension which will give you the inline declaration you’re looking for:

public class BooleanToVisibilityConverterExtension : MarkupExtension, IValueConverter
{
  private BooleanToVisibilityConverter converter;

  public BooleanToVisibilityCoverterExtension() : base()
  {
    this.converter = new BooleanToVisibilityConverter();
  }

  public override object ProvideValue(IServiceProvider serviceProvider)
  {
    return this;
  }

  public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
  {
    return this.converter.Convert(value, targetType, parameter, culture);
  }

  public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
  {
    return this.converter.ConvertBack(value, targetType, parameter, culture);
  }
}

Now you can use the MarkupExtension inline to create a new converter:

<Button Visibility="{Binding Converter={local:BooleanToVisibilityConverter} ...}" .. />