Updating GridView Data using LINQ

I have a GridView which needs to get updated on RowUpdating Event. How can I update data using LINQ?

I am populating GV using LINQ too and here is the code for that:

 protected void Page_Load(object sender, EventArgs e)
    {
         string getEntity = Request.QueryString["EntityID"];
         int getIntEntity = Int16.Parse(getEntity);
         using (OISLinq2SqlVs1DataContext dt = new OISLinq2SqlVs1DataContext())
         {
             var tr = from r in dt.Users
                      join s in dt.Entities on r.Entity_ID equals s.ID
                      where s.ID == getIntEntity
                      select new
                      {
                          s.Name,
                          r.FirstName,
                          r.LastName,
                          s.Email,
                          //r.Email,
                          r.UserID,
                          r.Pwd,
                          s.Company,
                          s.开发者_如何转开发Description,
                          s.Phone,
                          s.Fax,
                          s.WebSite

                      };

             gvShowRegistration.DataSource = tr;
             gvShowRegistration.DataBind();
         }

    }

What you're trying to do would be best accomplished with a LinqDataSource

Here's a good tutorial on it from Scott Gu

http://weblogs.asp.net/scottgu/archive/2007/07/16/linq-to-sql-part-5-binding-ui-using-the-asp-linqdatasource-control.aspx

EDIT

If you absolutely cannot use a Linq DS, then in your RowUpdating event you're going to have to create a new data context, re-read the object based on the DataKey from the row you're updating, assign the new values based on your event args, and then save your changes.

It's going to be a pain. Triple check that you can't use a LDS before going through all that.