frenchie frenchie - 2 months ago 16
C# Question

merging two objects in C#

I have an object model MyObject with various properties. At one point, I have two instances of these MyObject: instance A and instance B. I'd like to copy and replace the properties in instance A with those of instance B if instance B has non-null values.

If I only had 1 class with 3 properties, no problem, I could easily hard code it (which is what I started doing). But I actually have 12 different object models with about 10 properties each.

What's good way to do this?

Bas Bas
Answer

Update Use AutoMapper instead if you need to invoke this method a lot. Automapper builds dynamic methods using Reflection.Emit and will be much faster than reflection.'

You could copy the values of the properties using reflection:

    public void CopyValues<T>(T target, T source)
    {
        Type t = typeof(T);

        var properties = t.GetProperties().Where(prop => prop.CanRead && prop.CanWrite);

        foreach (var prop in properties)
        {
            var value = prop.GetValue(source, null);
            if (value != null)
                 prop.SetValue(target, value, null);
        }
    }

I've made it generic to ensure type safety. If you want to include private properties you should use an override of Type.GetProperties(), specifying binding flags.

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