C #: require indexer from method parameter

Question

I am writing a function that is a converter from one type of object to another. An object that is passed as a parameter of the Map method must have a line pointer to find the corresponding value in the object (or not). I don't care if the cartographer gets a dictionary, DataRow, DataReader, etc.

Is there a way to indicate that the parameter passed to the method should implement a string index? I can not find anything like it.

I use reflection to give type to something useful, if that is not possible, but I was wondering if he has the right way to handle it.

Answer 1

, . , , Andrew's, Func<T, string>, .

public void ConsumeIndexedFunction<T>(Func<string, T> something)
{
    var foo = something("bar");
    // do something with foo
}

public void TestMethod(
    Dictionary<string, object> myDictionary,
    DataTable myDataTable,
    IDataReader myDataReader)
{
    ConsumeIndexedFunction(x => myDictionary[x]);
    ConsumeIndexedFunction(x => myDataTable.Rows[0][x]);
    ConsumeIndexedFunction(x => myDataReader[x]);
}

( , . !)

Answer 2

:

interface IFoo
{
    String this[Int32 index] { get; set; }
}

, , , IFoo, , .

Answer 3

If you cannot make all the objects (or classes accordingly), you like to pass to the mapper implementation an interface that defines such an index, you will need to use reflection.

Answer 4

Will the interface help in this case:

interface IImplementMe {
    string this[int index]
    {
        get;
        set;
    }
}

Just ask the parameter to implement the interface