Get method name and type using lambda expression

Question

I am trying to write a function that will pull the name of a property and the type using syntax like bellow

private class SomeClass
{
    Public string Col1;
}

PropertyMapper<Somewhere> propertyMapper = new PropertyMapper<Somewhere>();
propertyMapper.MapProperty(x => x.Col1)

Is there any why to pass the property through to the function with out any major changes to this syntax.

What i would like to pull out is the property name and the property type.

so in the example bellow i would want to retrive name = "Col1" and type = "System.String"

Can anyone help.

Cheers Colin G

Answer 1

Cheers for the quick responce.

Had a feeling it might be a bit of a long shot will just have to rethink and come up with other syntax.

Cheers Again Colin G

Answer 2

Here's enough of an example of using Expressions to get the name of a property or field to get you started:

public static MemberInfo GetMemberInfo<T, U>(Expression<Func<T, U>> expression)
{
    var member = expression.Body as MemberExpression;
    if (member != null)
        return member.Member;

    throw new ArgumentException("Expression is not a member access", "expression");
}

Calling code would look like this:

public class Program
{
    public string Name
    {
        get { return "My Program"; }
    }

    static void Main()
    {
        MemberInfo member = ReflectionUtility.GetMemberInfo((Program p) => p.Name);
        Console.WriteLine(member.Name);
    }
}

A word of caution, though: the simple statment of (Program p) => p.Name actually involves quite a bit of work (and can take measurable amounts of time). Consider caching the result rather than calling the method frequently.

Answer 3

Jacob's answer is absolutely right. Always remember that a lambda expression can be converted into either a delegate or an expression tree.