Question

Exception:

Cannot convert the value in attribute ‘Text’ to object of type ‘System.String’. Unable to cast object of type ‘MyApp.Foo’ to type ‘System.String’.

XAML:

<Window.Resources>   <my:Foo x:Key='foo'></my:Foo> </Window.Resources>  <TextBox Text='{DynamicResource foo}'></TextBox> 

C#

[TypeConverter(typeof(FooConverter))] public class Foo {     public Foo()     {} }  public class FooConverter : TypeConverter {     public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType)     {         return true;     }      public override object ConvertTo(ITypeDescriptorContext context, System.Globalization.CultureInfo culture, object value, Type destinationType)     {         return 'Foo';     } } 

What is wrong?

Answer 1

Don’t you need to use a value converter there instead of a type converter.

XAML

<Window.Resources>       <my:Foo x:Key='foo'/>     <my:FooConverter x:Key='fooConverter /> </Window.Resources> <TextBox Text='{DynamicResource foo, Converter={DynamicResource fooConverter}}'></TextBox> 

C#

public class FooConverter : IValueConverter {       public object Convert(object value, Type targetType, object parameter, CultureInfo culture)      {           return ((Foo)value).ToString();      }  }