Method explanation

Question

Hi

Im having trouble understanding the following code:-

public new ViewStateProviderBase this[string name]
{
get { return base[name] as ViewStateProviderBase; }
}

Please could I get an explanation of each part, especially the this after the method name and the [string name].

Ive not come across a method wrote this way, how is it invoked?

Thanks
Steven

Vulpes · Answer

When you see a property with a name of 'this' it's defining an indexer for the class. In this case the indexer is taking a parameter (name) of type string and returning an object reference of type ViewStateProviderBase. By declaring it as 'new' it's hiding the base class indexer. The indexer is 'read onl'y because there's only a 'get'. The return value is computed by calling the base class indexer with the same parameter and casting it to ViewStateProviderBase. This suggests that the base class indexer itself returns an object reference for a class which derives from ViewStateProviderBase. This is how you'd invoke it assuming its containing class is called MyClass and has a parameterless constructor: MyClass mc = new MyClass(); ViewStateProviderBase vspb = mc[Steven];