Question

I’m working on a method that accepts an expression tree as a parameter, along with a type (or instance) of a class.

The basic idea is that this method will add certain things to a collection that will be used for validation.

public interface ITestInterface {     //Specify stuff here. }  private static void DoSomething<T>(Expression<Func<T, object>> expression, params IMyInterface[] rule) {     // Stuff is done here. } 

The method is called as follows:

class TestClass {     public int MyProperty { get; set; } }  class OtherTestClass  : ITestInterface {     // Blah Blah Blah. }  static void Main(string[] args) {     DoSomething<TestClass>(t => t.MyProperty,          new OtherTestClass()); } 

I’m doing it this way because I’d like for the property names that are passed in to be strong typed.

A couple of things I’m struggling with..

1. Within DoSomething, I’d like to get a PropertyInfo type (from the body passed in) of T and add it to a collection along with rule[]. Currently, I’m thinking about using expression.Body and removing [propertyname] from "Convert.([propertyname])" and using reflection to get what I need. This seems cumbersome and wrong. Is there a better way?
2. Is this a specific pattern I’m using?
3. Lastly, any suggestions or clarifications as to my misunderstanding of what I’m doing are appreciated and / or resources or good info on C# expression trees are appreciated as well.

Thanks!

Ian

Edit:

An example of what expression.Body.ToString() returns within the DoSomething method is a string that contains "Convert(t.MyProperty)" if called from the example above.

I do need it to be strongly typed, so it will not compile if I change a property name.

Thanks for the suggestions!

Answer 1

Collecting PropertyInfo objects from Expression.Body seems similar to my solution to another question.