Accesing a Class.Name property from diffrent classes without inheritance

Question

I am trying to write a Method that uses the Name property of diffrent classes and does some logic with it.

In my exampel to keep it simple i will restrict myself to simply returning the Name value:

class Dog
{
    public string Name { get; set; }
}

class Human
{
    public string Name { get; set; }
}

/*
 ...
*/

public string GetNameFromNameProperty(object obj)
{
    return obj.Name;
}

Sadly the classes are not inherting from a parent class that has the Name property. Furthermore it is not possible to implement that or add an interface.

Short Recap:
Is it possible to write a generic Method that uses a Name property without being sure that the class has implemented that property?

You should use an `interface` in which you defines the `Name` property. — ADreNaLiNe-DJ, Jul 28 '17 at 13:42
Is https://stackoverflow.com/questions/2998954/test-if-a-property-is-available-on-a-dynamic-variable an option? — mjwills, Jul 28 '17 at 13:44
No its not possible in C# without `dynamic` or Reflection, but a base class or interface is the more idiomatic, type-safe approach. — D Stanley, Jul 28 '17 at 13:44
But then i would have to implement the interfaces in all the classes that i wish to pass, e,g. in `Dog` and `Human`. If i am not mistaken it would be the same result as inheriting from a base class. — Squirrel in training, Jul 28 '17 at 13:44
So you mean you have lots of these classes and it's very hard to make them all implement an interface? — Sweeper, Jul 28 '17 at 13:46
What do you want to happen if `obj` does not have a `string Name` property? — Lee, Jul 28 '17 at 13:49
Possible duplicate of [Test if a property is available on a dynamic variable](https://stackoverflow.com/questions/2998954/test-if-a-property-is-available-on-a-dynamic-variable) — rene, Jul 28 '17 at 13:53

score 1 · Accepted Answer · edited Jul 28 '17 at 14:17

If you really don't want to make all those classes implement a common interface or inherit from a base class, then here are two options:

Reflection:

public string GetNameFromNameProperty(object obj)
{
    var type = obj.GetType();
    return type.GetProperty("Name").GetValue(obj) as string;
}

Dynamic Binding:

public string GetNameFromNameProperty(dynamic obj)
{
    try
    {
        return obj.Name;
    }
    catch (RuntimeBinderException)
    {
        throw new PropertyDoesntExistException();
    }
}

You can also choose to return null if the property does not exist.

However, I strongly advise you to use interfaces or inheritance to do this. You basically lose all the type-safety that C# provides if you used the above methods.

You answer is much higher quality than the one i compose. I still want to thank [mjwills](https://stackoverflow.com/users/34092/mjwills) who directed me to the right answer [here](https://stackoverflow.com/a/5768449/5757162) bevor you answerd it :) — Squirrel in training, Jul 28 '17 at 13:56

Accesing a Class.Name property from diffrent classes without inheritance

1 Answers1