AutoMapper doesn't map source to a destination

Question

I don't know why, at some point AutoMapper doesn't map source to a destination object.

   var result = Mapper.Map<User, User>(userToImport, userToUpdate);
   var areEquals = result == userToUpdate; //FALSE !!! Why?
   var areEquals2 = result.Equals(userToUpdate); //FALSE !!! Why?

userToUpdate is not updated with new values from userToImport. result is a correct resulting object of mapping. But result and userToUpdate are different objects.

The main problem is, why userToUpdate is not updated?

If you do not create the map first Mapper.CreateMap<User, User>(); the destination object will not be filled with the values of the source object, but the returning object will be filled. Also, you are comparing 2 different references and that will return false in this case. You need to override operator == or Equals function and do your comparison logic (this.prop1 == obj.prop1) — leskovar
– leskovar, Commented Apr 25, 2014 at 8:19
@leskovar Mapper.Map<,>() returns the SAME reference specified in the destination argument. So a comparison with either Equals or == will result in true if a map exists (See my answer). No overriding is needed, the problem lies in the missing CreateMap. — Alex
– Alex, Commented Apr 25, 2014 at 10:46
@Alex yes, exactly I have not called CreateMap. This was the cause why I've got such behavior. And it was weird for me. — Andrei
– Andrei, Commented Apr 25, 2014 at 11:49

Alex · Accepted Answer · 2014-04-25 08:09:12Z

5

You'll have to create a map first or else it won't update and return the object of the destination parameter.

 Mapper.CreateMap<User, User>();

edited Apr 25, 2014 at 8:09

answered Apr 25, 2014 at 7:51

Alex

8,1561 gold badge45 silver badges61 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Gert Arnold Over a year ago

This actually turns out to be true. I'm a bit surprised that AM doesn't throw an exception when the mapping is not created.

Andrei Over a year ago

I suspect you are right. Because it worked for me in the past. I will check and get back to you later. Thanks!

leskovar · Accepted Answer · 2014-04-25 07:57:31Z

-2

You need to do something like this:

public class User
{
    public int Property1 { get; set; }
    public int Property2 { get; set; }

    public override bool Equals(object obj)
    {
        if (!(obj is User))
            return false;
        else
        {
            Usero = obj as User;
            return o.Property1 == this.Property1 && o.Property2 == this.Property2;
        }

    }
}

After that you can do obj1.Equals(obj2);

answered Apr 25, 2014 at 7:57

leskovar

6613 silver badges8 bronze badges

1 Comment

Alex Over a year ago

This has nothing to do with it. AutoMapper.Map(source,destination) returns the destination object.

Collectives™ on Stack Overflow

AutoMapper doesn't map source to a destination

2 Answers 2

2 Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related