Sharepoint how to add field to list where field with such name already exists?

Question

I have sharepoint list 'Events' with field Location.

I am trying to add from web existing field with same internal name from other package.

    var fields = contentType.ParentWeb.Fields;

 SPField fieldToAdd = null;
                foreach (SPField field in fields)
                {
                    if (field.Id == fieldId)
                    {
                        fieldToAdd = field;
                        break;
                    }
                }

 contentType.FieldLinks.Add(new SPFieldLink(fieldToAdd));

And i got exception:

A duplicate field name "Location" was found.

When i am adding this fields in sharepoint UI it will be changed to Location0 and will be successfully added!

How to do actually the same in code? I want to add them both and its acceptable to change one internal name to Location0.

Answer 1

Did not get your code clearly, what is fieldId and how are you getting this fieldId? my guess is location is already there in the content type you can not add the same field again, create a new field if you wish, in that case your code will be (after foreach) -

string fldName = fields.Add(fieldToAdd.Title, fieldToAdd.Type, fieldToAdd.Required);
SPField newField = fields.GetField(fldName);
contentType.FieldLinks.Add(new SPFieldLink(newField));

In this case a new field is created with same display name and same type as fieldToAdd, but with different internal name (you dont have to worry about what the internal name is, system will determine) and add that field to your content type

P.S. - you should consider using break; after fieldToAdd = field;

:)