Using LINQ to group a list of objects

Question

I have an object:

public class Customer
{
    public int ID { get; set; }
    public string Name { get; set; }
    public int GroupID { get; set; }
}
         


        

Answer 1

var result = from cx in CustomerList
         group cx by cx.GroupID into cxGroup
     orderby cxGroup.Key
     select cxGroup; 

foreach (var cxGroup in result) { 
Console.WriteLine(String.Format("GroupID = {0}", cxGroup.Key)); 
  foreach (var cx in cxGroup) { 
    Console.WriteLine(String.Format("\tUserID = {0}, UserName = {1}, GroupID = {2}", 
      new object[] { cx.ID, cx.Name, cx.GroupID })); 
  }
}