Question

I want to determine whether MyBindingSource.DataSource is assigned to the designer set Type, or if it has been assigned an object instance. This is my current (rather ugly) solution:

Type sourceT = MyBindingSource.DataSource.GetType();
if( sourceT == null || sourceT.ToString().Equals("System.RuntimeType") ) {
     return null;
}
return (ExpectedObjType) result;

The System.RuntimeType is private and non-accessible, so I can’t do this:

Type sourceT = MyBindingSource.DataSource.GetType();
if ( object.ReferenceEquals(sourceT, typeof(System.RuntimeType)) ) {
     return null;
}
return (ExpectedObjType) result;

I was just wondering if a better solution exists? Particularly one that doesn’t rely on the Type name.

Answer 1

Since System.RuntimeType is derived from System.Type you should be able to do the following:

object result = MyBindingSource.DataSource;
if (typeof(Type).IsAssignableFrom(result.GetType()))
{
    return null;
}
return (ExpectedObjType)result;

or even more concisely:

object result = MyBindingSource.DataSource;
if (result is Type)
{
    return null;
}
return (ExpectedObjType)result;

Coincidentally this is the approach adopted here.