How do I convert a Color to a Brush in XAML?

Question

I want to convert a System.Windows.Media.Color value to a System.Windows.Media.Brush. The color value is databound to a Rectangle object's Fill property. The Fill property takes a Brush object, so I need an IValueConverter object to perform the conversion.

Is there a built-in converter in WPF or do I need to create my own? How do I go about creating my own if it becomes necessary?

Answer 1

It seems that you have to create your own converter. Here a simple example to start:

public class ColorToSolidColorBrushValueConverter : IValueConverter {

        public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture) {
            if (null == value) {
                return null;
            }
            // For a more sophisticated converter, check also the targetType and react accordingly..
            if (value is Color) {
                Color color = (Color)value;
                return new SolidColorBrush(color);
            }
            // You can support here more source types if you wish
            // For the example I throw an exception

            Type type = value.GetType();
            throw new InvalidOperationException("Unsupported type ["+type.Name+"]");            
        }

        public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture) {
            // If necessary, here you can convert back. Check if which brush it is (if its one),
            // get its Color-value and return it.

            throw new NotImplementedException();
        }
    }

To use it, declare it in the resource-section.

 <local:ColorToSolidColorBrushValueConverter  x:Key="ColorToSolidColorBrush_ValueConverter"/>

And the use it in the binding as a static resource:

  Fill="{Binding Path=xyz,Converter={StaticResource ColorToSolidColorBrush_ValueConverter}}"

I have not tested it. Make a comment if its not working.