MVVMCross WPF ValueConverter has invalid cast [closed] - wpf

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I am trying to bind a foreground color to a WPF Textblock.
The property in the view model is a color, as directed by MvvmCross documentation:
private System.Drawing.Color _setValueColor;
public System.Drawing.Color SetValueColor
{
get { return _setValueColor == null ? System.Drawing.Color.Green : _setValueColor; }
set { SetProperty(ref _setValueColor, value); }
}
The xaml text block is
<TextBlock Grid.Column="3" Grid.Row="1" Margin="20"
Text="{Binding SetMessage}" Foreground="{Binding SetValueColor, Converter={StaticResource NativeColor}}">
</TextBlock>
I have a resources dictionary resource.xaml file which references the plug in. The plug-in is installed as a nu-get MvvmCross.Plugin.Color 7.1.2
<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:color="clr-namespace:MvvmCross.Plugin.Color;assembly=MvvmCross.Plugin.Color"
<color:MvxNativeColorValueConverter x:Key="NativeColor" />
</ResourceDictionary>
On the view I add the resource in the constructor
public SimpleReadWriteView()
{
var resourceDict = new System.Windows.ResourceDictionary();
resourceDict.Source = new Uri("Resource.xaml", UriKind.Relative);
Resources.MergedDictionaries.Add(resourceDict);
InitializeComponent();
}
When it's run, it throws a cast error:
InvalidCastException: Unable to cast object of type
'MvvmCross.Plugin.Color.MvxnativeColorValueConverter' to type
'System.Windows.Data.IValueConverter'.
I also tried to create my own converter by inheriting from MvxValueConverter and I get the same type of cast error, the converter cannot be cast to type System.Windows.Data.IValueConverter.

Answer 1

Do not use System.Drawing.Color in a WPF application, it is a WinForms type. Use System.Windows.Media.Color instead:
private System.Windows.Media.Color setValueColor = System.Windows.Media.Colors.Green;
public System.Windows.Media.Color SetValueColor
{
get { return setValueColor; }
set { SetProperty(ref setValueColor, value); }
}
You do not need a Binding Converter. You may instead directly bind the Color property of a SolidColorBrush:
<TextBlock ... >
<TextBlock.Foreground>
<SolidColorBrush Color="{Binding SetValueColor}" />
</TextBlock.Foreground>
</TextBlock>
Besides that, a converter from Color to Brush would look like this:
public class ColorToBrushConverter : IValueConverter
{
public object Convert(
object value, Type targetType, object parameter, CultureInfo culture)
{
return new SolidColorBrush((Color)value);
}
public object ConvertBack(
object value, Type targetType, object parameter, CultureInfo culture)
{
return ((SolidColorBrush)value).Color;
}
}