Getting all methods from a code file with Roslyn

Posted by Filip Ekberg on 21 Oct 2011

In the previous post we started looking at Roslyn and let's continue on this topic and see what else we can get out of it! I want to take a look at how we can retrieve all methods and get some information about them. I've added another method to the Person-class so it looks like this now:

public class Person
{
    public string Name { get; private set; }
    public Person(string name)
    {
        Name = name;
    }
    public void Evaporate()
    {

    }
    public string Speak()
    {
        string str = "test";
        return string.Format("Hello! My name is{0}",
            Name);
    }
}

We've already got the tree-structure and the root node so let's just use that. Everything is represented as a SyntaxNode so we need to get all the descending nodes that are methods, methods are declared as MethodDeclarationSyntax. So all methods are retrieved like this:

IEnumerable<MethodDeclarationSyntax> methods = tree.Root
            .DescendentNodes()
            .OfType<MethodDeclarationSyntax>().ToList();

No we can just iterate over this:

foreach(var method in methods)
{
}

However, you might be a bit confused as to how you print the method name, because there's not a Name-property on the object! Instead there is something called an Identifier that we can use:

foreach(var method in methods)
{
    Console.WriteLine(method.Identifier);
}

This will print all methods and not including the constructors, if we want to get the constructors we ask for ConstructorDeclarationSyntax instead of MethodDeclarationSyntax. We can get a lot of interesting things from the method-object in the iterator, we can ask about the parameters, the return type and a lot of other nice things.

I hope you found this interesting, if you have any thoughts please leave a comment below!

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