In my window.xaml I have the following code:

 xmlns:converters="clr-namespace:HMIPlc.Helpers"

 <Window.Resources>
    <ResourceDictionary>
        <converters:ColorConverter x:Key="ColorOnChange"/>
    </ResourceDictionary>
</Window.Resources>

<Rectangle Fill="{Binding Path=varUnit.InSimulation, Converter={StaticResource ColorOnChange}}"/> 

I want to give also a value in a string "Yellow" or "Orange" to the function, so I can use the same function for different rectangles with different colors.

My ColorConverter.cs class inside the Helpers directory:

public class ColorConverter : IValueConverter
{
    public ColorConverter()
    {
    }

    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        bool tempBool = (bool)value;
        if(tempBool == true)
        {
            return new SolidColorBrush(Colors.Orange);
        } else
        {
            return new SolidColorBrush(Colors.White);
        }
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

So that I can determine in my XAML if the color has to be orange or yellow. Is there any good method to do this?

CodePudding user response：

When you want to provide additional values to a converter, you can either:

a) Add additional properties on the converter which can then be assigned in XAML:

public class ColorConverter : IValueConverter
{
    public Color BackupColor { get; set; }

    public ColorConverter()
    {

    }

    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        bool tempBool = (bool)value;
        if(tempBool == true)
        {
            return new SolidColorBrush(Colors.Orange);
        } else
        {
            return new SolidColorBrush(Colors.White);
        }
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}```

```xaml
...
<converters:ColorConverter x:Key="ColorOnChange" BackupColor="Yellow"/>
...

b) Leverage the CommandParameter which is usually a string literal:

<Rectangle Fill="{Binding Path=varUnit.InSimulation, Converter={StaticResource ColorOnChange}, CommandParameter='Yellow'}"/>

CodePudding user response：

If you want to bind multiple values, use a MultiValueConverter. I use the more general type Brush here, so you are not limited to binding a SolidColorBrush.

public class ColorConverter : IMultiValueConverter
{
   public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
   {
      if (values.Length != 3 ||
          !(values[0] is bool value) ||
          !(values[1] is Brush brushTrue) ||
          !(values[2] is Brush brushFalse))
         return Binding.DoNothing;

      return value ? brushTrue : brushFalse;
   }

   public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
   {
      throw new NotImplementedException();
   }
}

Then use a MultiBinding and specify the property to be bound, as well as the brushes. In order to reference a built-in brush, you can use the static Brushes type with x:Static.

<Rectangle>
   <Rectangle.Fill>
      <MultiBinding Converter="{StaticResource ColorOnChange}">
         <Binding Path="varUnit.InSimulation"/>
         <Binding Source="{x:Static Brushes.Orange}"/>
         <Binding Source="{x:Static Brushes.White}"/>
      </MultiBinding>
   </Rectangle.Fill>
</Rectangle>

CodePudding user response：

You could set the CommandParameter property to a Brush or Color and cast the "parameter" argument in your converter:

public class ColorConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        Color color = (Color)parameter;
        bool tempBool = (bool)value;
        if (tempBool == true)
        {
            return new SolidColorBrush(color);
        }
        else
        {
            return new SolidColorBrush(color);
        }
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

XAML:

<Rectangle Fill="{Binding Path=varUnit.InSimulation, Converter={StaticResource ColorOnChange},
        ConverterParameter={x:Static Colors.Orange}}"/>