Question

The DateTimeConverter class provides conversions between DateTime and string. I would also like to support conversions between DateTime and double.

According to MSDN I can extend the DateTimeConverter class to do this – see MSDN DateTimeConverter

I have created a class that inherits from DateTimeConverter and provides the appropriate overrides for CanConvertTo, CanConvertFrom, etc.

How do I make sure that the framework uses my DateTime converter (DateTimeConverterEx) instead of the one provided in the BCL (DateTimeConverter) when the code below is called?

    DateTime dt = DateTime.Now;     // This line returns a DateTimeConverter which I don't want.      // Would like to get a DateTimeConverterEx.     TypeConverter tc = TypeDescriptor.GetConverter(dt);     double dbl = (double)tc.ConvertTo(dt, typeof(double)); 

Thanks.

Answer 1

You need to allocate the converter. On a property-by-property basis, you can use:

[TypeConverter(typeof(DateTimeConverterEx))] public DateTime Foo {get {...} set {...}} 

This would then work for usage of the form:

var prop = TypeDescriptor.GetProperties(obj)['Foo']; var converter = prop.Converter; // as before, using 'converter' 

This will work for most common binding scenarios.

(edit)

To set the converter for any DateTime:

TypeDescriptor.AddAttributes(typeof(DateTime),     new TypeConverterAttribute(typeof(DateTimeConverterEx))); 

Now your sample code should work.