Need clarification concerning Action<T>

Here is a method used to save data to a file which has stumped me:

public void SaveData(string filename, Action<StreamWriter> saveAction)

The documentation for the library describes the second parameter as "A delegate action to handle actually writing the data". I am lost, however, on how to actually create an action for a StreamWriter. I've done some research and found a lot of stuff like this used as examples for Action<T>:

Action<string> s = Console.WriteLine;

And from that I infer that <T> is the parameter type passed and the Action is the method which takes this parameter. I am aware that this may be terribly wrong.

Basically all I want to do is use StreamWriter.WriteLine(string line). However, I cannot use

Action<StreamWriter> s = StreamWriter.WriteLine;

Because that makes no sense, plus it is impossible for me to reference StreamWriter.WriteLine anyway. Right now I'm thinking that there must be a method which takes StreamWriter from a class which I am not aware of. If anyone would care to point me in the right direction I would be very grateful.

You may ask why I can't just create my own StreamWriter and do it the way I've always done it. Well, I'm working in XNA on the Zune, so writing to a text file is actually quite d开发者_如何学编程ifficult with all the levels of protection (all apps are sandboxed), and the libraries I'm using right now promise to make it far more streamlined if I can just figure out how to use Action<T> effectively. Plus, I want to learn and be better equipped to use delegates in the future.

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Probably the API is intended to be used like this:

SaveData(filename, writer => writer.WriteLine(saveData));

The => notation concisely declares an anonymous function. You could write it in a longer fashion like this:

private static void SaveToWriter(StreamWriter writer)
{
    // get saveData somehow
    writer.WriteLine(saveData);
}

// ...

SaveData(filename, SaveToWriter);

which might help explicate the type signatures involved.