How to automatically map the values between instances of two different classes if both have same properties?

c#

Solution

One possibility to make this (for example for the purpose of creating your own automapper or understand how it basically works) would be to use (as already suggested) Reflection. The code can look like this:

// TODO: error handling
// Test classes
public class A
{
    public string Name { get; set; }
    public int Count;
}

public class B
{
    public string Name { get; set; }
    public int Count;
}
// copy routine
public B CopyAToB(A a)
{
    B b = new B();
    // copy fields
    var typeOfA = a.GetType();
    var typeOfB = b.GetType();
    foreach (var fieldOfA in typeOfA.GetFields())
    {
        var fieldOfB = typeOfB.GetField(fieldOfA.Name);
        fieldOfB.SetValue(b, fieldOfA.GetValue(a));
    }
    // copy properties
    foreach (var propertyOfA in typeOfA.GetProperties())
    {
        var propertyOfB = typeOfB.GetProperty(propertyOfA.Name);
        propertyOfB.SetValue(b, propertyOfA.GetValue(a));
    }

    return b;
}

The function can be used like this:

var a = new A
{
    Name = "a",
    Count = 1
};

var b = CopyAToB(a);
Console.Out.WriteLine(string.Format("{0} - {1}", b.Name, b.Count));

The output is:

a - 1

Please note, that the usage of reflection comes with a price - it costs performance. Using reflection you can access both private and public object members. This is for example used from Visual Studio to create test accessor objects in order to access all test object members.

Please have a look at the existing automappers (see the other answers for links) and use them instead of reinventing the wheel by yourself - the existing libraries are optimized for speed, thoroughly tested and are very comfortable to use. This way you will minimize errors in your code.

Problem

I have two classes with exactly same members (properties and fields) with same datatypes. I want to map the members from one to other in automated way. I know there are more practical means development-wise to handle. One simple solution is to manually map each member from one instance to other. But, I want to automate this as some general solution. Assuming you have the following code: ``` public MyObject1 AssignTest (MyObject1 obj1, MyObject2 obj2) { //Code here for auto map } ``` Where `MyObject1` and `MyObject2` have the exact same properties with same datatype. I do not want to go through and assign the values individually (i.e. `MyObject1.Property1 = MyObject2.Property1` etc.). Is it possible to assign all the values that have been specified in `MyObject1` to `MyObject2` automatically?

Original source

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