gridview中添加dropdownlist后实现数据库更新

背景描述：gridview已经通过选择数据源实现了数据绑定，并选择了编辑操作，并在gridview中添加dropdownlist。
目的：点击编辑，然后选择dropdownlist，然后在数据库中更新该row（只需要更新update dropdownlist所选），并在当前gridview中显示最终结果。

  DropDownList ddl = GridView1.Rows[e.RowIndex].FindControl("DropDownList1") as DropDownList;
                    string id = ddl.Text;
                    int zz = int.Parse(GridView1.Rows[e.RowIndex].Cells[1].Text);
                    Response.Write(zz.ToString());
                    SqlConnection sqlcon = new SqlConnection(System.Web.Configuration.WebConfigurationManager.ConnectionStrings["Con"].ConnectionString.ToString());
                    sqlcon.Open();
                    string str = "update Task_inf set TaskMajorEng='" + id + "' where ID='"+zz+"'";
                    SqlCommand cmd = new SqlCommand(str, sqlcon);
                    cmd.ExecuteNonQuery();
                    sqlcon.Close();

http://www.cnblogs.com/lds85930/articles/648984.html