Since the SolidColorBrush() method mentioned by is part of the library, it uses the Color type from that same library. I here provide the Converter I taking the parameter. To make this converter general you may use a ConverterParameter for specifying the colors which is to be inserted when value is true or false. This is demonstrated in the second TextBlock which uses a property Trigger to check its own IsEnabled property against the value of true (since its IsEnabled property will be the same as its parent's). That is, if you set IsEnabled to false on your Button, then your TextBlock will have its IsEnabled property updated to false automatically. However, this is overkill - the IsEnabled property is propagated down to children automatically by WPF. In the example above, the first TextBlock binds to its parent's IsEnabled property using a DataTrigger, and sets the Foreground to some colour if it is true. However, do you really need to use a converter? This can be done in XAML only using Triggers:
#WPF COLORCONVERTER HOW TO#
The answer above shows you how to correctly you use a converter. Public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)īutton's enable,isable property changes from viewmodel(e.g using RaiseCanExecuteChanged)()) Public object Convert(object value, Type targetType, object parameter, CultureInfo culture) public class BrushColorConverter : IValueConverter I have declared following class in my "Models" folder. I want to set foreground of my textblock to black color when its associated button's isEnabled is true. If (o = null || o = DependencyProperty.I am working on WPF application.I have bound my textblock to my button. Protected static double GetDoubleValue(Object o) Protected virtual bool Compare(double a, double b) / Overload in subclasses to create LesserThan, EqualTo, whatever. Throw new ArgumentException("Exactly two values are expected") Public virtual object Convert(object values, Type targetType, object parameter, CultureInfo culture)
Public class ComparisonConverter : MarkupExtension, IMultiValueConverter New FrameworkPropertyMetadata(Brushes.White)) Public static readonly DependencyProperty InactiveBarFillBrushProperty =ĭependencyProperty.Register("InactiveBarFillBrush", typeof(Brush), typeof(SignalBars), But sometimes the semantics are so clear, the property name is unnecessary. I don't think that's a good fit for this case. public BoolBrushConverter(Brush tb, Brush fb) You could give BoolBrushConverter a constructor that takes parameters, too. Public override object ProvideValue(IServiceProvider serviceProvider) Public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
Public class BoolBrushConverter : MarkupExtension, IValueConverter This works with any type, of course, not just Brush. Since the XAML parser knows the types of the properties declared on the class, it will apply the default TypeConverter for Brush, and you'll get the exact same behavior as if you were assigning "PapayaWhip" to "Border.Background" or anything else.
If you derive a converter from MarkupExtension, you can assign named and typed properties when you use it, and also not have to create it as a resource (indeed, creating it as a resource would break the thing, since that would be a shared instance and the properties are initialized when it's created). Your case may not be best addressed by the method you've chosen (it makes it hard to parameterize the colors of the segments), but your specific question is a good one, so I'll answer it.Īs you've found, it's tough to pass anything but a string to ConverterParameter.
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