Cast into new Object, Copy values by Property Name

Question

Hello, I have the following:

Class 1 (Text, State, Level)
Class 2 (Text, State, Level, Ident)

Is there a way for me to cast an object of Class 2 into into Class 1, and not having to do the usual cast code (Text = c.Text, State = c.State etc.)? Possibly by identifying the property names of each class and copying the value over?

Answer 1

It might be overkill for your specific problem, but Automapper can help with this problem.

Answer 2

Why not derive Class 2 from Class 1, or have a common base class?

e.g.

class Class1 
{ 
   string Text;
   string State; 
   int    Level; 
} 

class Class2 : Class1 
{ 
   int Ident;
   // ...
}

A Class 2 instance can now be used everywhere a Class 1 instance is required.

Answer 3

Here is a very simple example without any error checking, it simply uses reflection to iterate over the properties of the source object and set the value of the destination object only if the types match.

class Program
{
    static void Main(string[] args)
    {
        var bar = new Bar();
        var foo = new Foo {A = 10, B = "Hello World"};

        foo.CopyTo(bar);

        Console.WriteLine("{0} - {1}", bar.A, bar.B);
    }
}

public static class Extensions
{
    public static void CopyTo(this object source, object destination)
    {
        var sourceType = source.GetType();
        var destinationType = destination.GetType();

        const BindingFlags flags = BindingFlags.Public | BindingFlags.Instance;

        var properties = sourceType.GetProperties(flags);
        foreach (var sourceProperty in properties)
        {
            var destinationProperty = destinationType.GetProperty(sourceProperty.Name, flags);
            if (destinationProperty.PropertyType.Equals(sourceProperty.PropertyType))
            {
                destinationProperty.SetValue(destination, sourceProperty.GetValue(source, null), null);
            }
        }
    }
}

Answer 4

Maybe the problem is more complicated than the question. If not, have you tried inheritance?

class Class1
{
  //Text, State, Level
}

class Class2 : Class1
{
  //Indent
} 

Since Class2 inherits from class 1, you can pass it around as Class1 no casting needed. This works for example:

Class1 obj = new Class2();