Method to handle objects with properties in common, but different object types

Question

I have a large collection of automatically generated objects. Although they are all of different, non-related classes, all of the objects share some basic properties (name, id, etc.). I do not control the generation of these objects, so unfortunately I cannot take the ideal approach of implementing an interface. I would like to create a method in which I pass an arbitrary one of these objects and do something using these common properties.

The general idea would be something like:

someObj a = new someObj();
a.name = "sara";
diffObj b = new diffObj();
b.name = "joe";
string phrase = string.Format("I am with {0} and {1}", 
    getName(a), getName(b));

private string getName(object anyObjWithName)
{
    return anyObjWithName.name;
}

though naturally this does not work.

I thought a generic method might hold the answer, but the only way I can see to call it with the current type is using genericMethod.Invoke , which still carries the same issue of not being able to resolve the properties of the passed object in the method. This is unlike Calling generic method with a type argument known only at execution time or How to call generic method with a given Type object? where only the type, or properties of the type, are used in the method, as opposed to properties of the object.

I am aware that this would be (very) prone to error, but I can guarantee that all objects encountered will have the common properties being manipulated.

Answer 1

I can guarantee that all objects encountered will have the common properties being manipulated

If that's the case, you can use dynamic:

private string getName(dynamic anyObjWithName)
{
    return anyObjWithName.name;
}

Be aware that using any object that does not have a name property will not fail until run-time.

If you want to add a little bit of safety you can catch the RuntimeBinderException that gets thrown if the property does not exist:

private string getName(dynamic anyObjWithName)
{
    try {
        return anyObjWithName.name;
    }
    catch(RuntimeBinderException) {
        return "{unknown}";
    }
}

Answer 2

If you're unhappy with the performance using dynamic as mentioned by D Stanley, you could always try FastMember.

All you need to know to start using it is pretty much shown in the first 2 code examples.