Populate ASP.Net DropDownList control using LINQ

http://www.codeproject.com/Tips/590978/LINQ-Tutorial-for-Beginners

http://code.msdn.microsoft.com/101-LINQ-Samples-3fb9811b

try this

varRecordCounts = (from tcount inRecordsgroup tcount by tcount.Field<string>

("User_Id")into g  selectnew{Userid=g.Key,rcount=g.Count(ts=>ts.Field<string>("Record")!=null)}).ToList(); 

GridView1.DataSource=RecordCounts; 

GridView1.DataBind();