How can I get the properties of an inherited object when the parameter is declared as a base type?

Question

I have a simple program that uses reflection to print out the properties and values of the supplied class.

class BaseClass
{
    public string A
    {
        get { return "BaseClass"; }
    }
}

class Child1 : BaseClass
{
    public string Child1Name {
        get { return "Child1"; }
    }
}

class Child2 : BaseClass
{
    public string Child2Name
    {
        get { return "Child2"; }
    }
}

class Program
{
    static void Main(string[] args)
    {
        var child1 = new Child1();
        var child2 = new Child2();
        SomeMethod(child1);
        SomeMethod(child2);

        Console.ReadKey();
    }

    static void SomeMethod(BaseClass baseClass)
    {
        PrintProperties(baseClass);
    }

    static void PrintProperties<T>(T entity)
    {
        var type = typeof(T);

        foreach (var targetPropInfo in type.GetProperties())
        {
            var value = type.GetProperty(targetPropInfo.Name).GetValue(entity);
            Console.WriteLine("{0}: {1}", targetPropInfo.Name, value);
        }
        Console.WriteLine("");
    }
}

The problem is that it only prints out the BaseClass properties because I am using generics and passing in the BaseClass into the PrintProperties method.

Output:

A: BaseClass

A: BaseClass

How do I access the properties of the Child classes? I would like an output like:

A: BaseClass
Child1Name: Child1

A: BaseClass
Child2Name: Child2

Answer 1

The problem here is that you're using typeof(T) in PrintProperties, but the T in your example is BaseClass because that's the type of the parameter you give it from SomeMethod.

In your example, remove SomeMethod, call the PrintProperties method directly and it'll work.

A simpler way would be to use entity.GetType() instead of typeof(T). That way, no matter what the generic type is, you'll always get the true type of the object.