Question

What is the difference between PropertyType and ComponentType on a .NET PropertyDescriptor?

The docs didn’t really explain

PropertyType When overridden in a derived class, gets the type of the property.

ComponentType When overridden in a derived class, gets the type of the component this property is bound to.

Answer 1

In terms of a regular property:

class Foo
{
    public int Bar { get; set; }
}

If we now look at Foo.Bar via TypeDescriptor, the component-type is Foo; the property-type is Int32. Basically, ComponentType is the DeclaringType of the property (in reflection terms). So if you are writing a custom PropertyDescriptor implementation, the PropertyType is the type of the data, and ComponentType is the expected type of the target instance.