Question

I have an class that implements an interface. I’d like to examine only the property values that implement my interface.

So, let’s say for example I have this interface:

public interface IFooBar {
    string foo { get; set; }
    string bar { get; set; }
}

And this class:

public class MyClass :IFooBar {
    public string foo { get; set; }
    public string bar { get; set; }
    public int MyOtherPropery1 { get; set; }
    public string MyOtherProperty2 { get; set; }
}

So, I need to accomplish this, without the magic strings:

var myClassInstance = new MyClass();
foreach (var pi in myClassInstance.GetType().GetProperties()) {
    if(pi.Name == "MyOtherPropery1" || pi.Name == "MyOtherPropery2") {
        continue; //Not interested in these property values
    }
    //We do work here with the values we want. 

}

How can I replace this:

if(pi.Name == 'MyOtherPropery1' || pi.Name == 'MyOtherPropery2') 

Instead of checking to see if my property name is == to a magic string, I’d like to simply check to see if the property is implemented from my interface.

Answer 1

Why use reflection if you know the interface ahead of time? Why not just test if it implements the interface then cast to that?

var myClassInstance = new MyClass();
var interfaceImplementation = myClassInstance as IFooBar

if(interfaceImplementation != null)
{
    //implements interface
    interfaceImplementation.foo ...
}

If you really must use reflection, get the properties on the interface type, so use this line to get properties:

foreach (var pi in typeof(IFooBar).GetProperties()) {