Question

I have a type that has index properties which I want to access via reflection. How can I do that? I suppose an index property is retrievable as a normal property but I have no idea how to get to it by the means of standard reflection. Also, if I have multiple index properties with different signatures like in the following code, is it possible to access each of them?

public class IndexType
{
   // Assume some sensible implementation of the getters/setters

   public object this[int index] { get; set; }

   public object this[string key] { get; set; }

   public object this[int index, string key] { get; set; }
}

Answer 1

You should be able to differentiate an index property by the fact that it requires index parameters. This linq query should do that by checking the GetIndexParameters method.

IEnumerable<PropertyInfo> indexProperties = 
    O.GetType().GetProperties().Where(pi => pi.GetIndexParameters().Any());

Differentiating which is which can be done by inspecting the numbers and type of parameters.

After providing a sensible implementation of your index properties, this code:

        foreach (PropertyInfo pi in indexProperties) {
            foreach (ParameterInfo parm in pi.GetIndexParameters()) {
                Console.WriteLine(parm.ParameterType.ToString());
            }
            Console.WriteLine();
        }

Yields:

System.Int32

System.String

System.Int32
System.String

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