SPFieldUserValue is not working with SPMetal generated CreatedBy column

Question

I'm trying to get Document Authors (Created By) Email Id using SPMetal generated class code.

It gives DocumentCreatedBy as one of the Sharepoint Foundation Base field.

When I try to get LoginName from that field I'm getting the following error:

Value does not fall within the expected range

Here is my code...

DocumentsDocument docItem
SPFieldUserValue usrValue = new SPFieldUserValue(web, docItem.DocumentCreatedBy);

//I tried this too...But no luck....:(
//SPFieldUserValue usrValue = new SPFieldUserValue(web, "Created_x0020_By");

SPUser docUser = usrValue.User;
var usrEmail = docUser.LoginName;

Answer 1

you can get the userid or DisplayName from a USER field with Linq2Sharepoint.

write a partial class like this.

public partial class DocumentsDocument 
{
    private string _sysAuthor;
    [Microsoft.SharePoint.Linq.ColumnAttribute(Name = "Created_x0020_By", Storage = "_sysAuthor", ReadOnly = true, FieldType = "User", IsLookupValue = true)]
    public string SysAuthor
    {
        get
        {
            return this._sysAuthor;
        }
        set
        {
            if ((value != this._sysAuthor))
            {
                this.OnPropertyChanging("SysAuthor", this._sysAuthor);
                this._sysAuthor = value;
                this.OnPropertyChanged("SysAuthor");
            }
        }
    }

    private System.Nullable<int> _sysAuthorId;
    [Microsoft.SharePoint.Linq.ColumnAttribute(Name = "Created_x0020_By", Storage = "_sysAuthorId", ReadOnly = true, FieldType = "User", IsLookupId = true)]
    public System.Nullable<int> SysAuthorId
    {
        get
        {
            return this._sysAuthorId;
        }
        set
        {
            if ((value != this._sysAuthorId))
            {
                this.OnPropertyChanging("SysAuthorId", this._sysAuthorId);
                this._sysAuthorId = value;
                this.OnPropertyChanged("SysAuthorId");
            }
        }
    }
}

then you can retrieve a SPUser like this

SPUser user = web.AllUsers.GetByID(docItem.SysAuthorId);

Answer 2

Are you able to run a debug session? If you look at the usrValue object, what's returned? The display name is Created By but I believe the internal field name is Author.