大家帮我看看我怎么错了，，急急急，，，在线等！！！！！
static void Main(string[] args)
  {
  DataTable dt = new DataTable();
  dt.Columns.Add("id", typeof(System.Int32));
  dt.Columns.Add("val",typeof(System.Int32));
  DataRow dr1 = dt.NewRow();
  dr1["id"] = 1; dr1["val"]=111;
  DataRow dr2 = dt.NewRow();
  dr2["id"] = 2; dr2["val"]=222;
  dt.Rows.Add(dr2);

  string strCon = "Data Source=.;Initial Catalog=test;Integrated Security=True";
  SqlConnection sqlCon = new SqlConnection(strCon);
  SqlCommand cmd = new SqlCommand();

  cmd.Connection = sqlCon;
  sqlCon.Open();
  SqlTransaction trans = sqlCon.BeginTransaction(); //开始执行事务
  try
  {
  foreach (DataRow dr in dt.Rows)
  {
  cmd.CommandText = "update tb_2 set val = @val where id = @id";
  cmd.Parameters.Add("@id", SqlDbType.Int);
  cmd.Parameters["@id"].Value = Convert.ToInt32(dr["id"].ToString());
  cmd.Parameters.Add("@val", SqlDbType.Int);
  cmd.Parameters["@val"].Value = Int32.Parse(dr["val"].ToString());
  cmd.ExecuteNonQuery();
  }
  trans.Commit();
  }
  catch(Exception ex)
  {
  Console.WriteLine(ex.ToString());
  trans.Rollback();
  }
  finally
  {
  sqlCon.Close();
  trans.Dispose();
  sqlCon.Dispose();
  }

  Console.Read();
  }



提示：如果分配给命令的连接位于本地挂起事务中，ExecuteNonQuery 要求命令拥有事务。命令的 Transaction 属性尚未初始化

------解决方案--------------------
cmd 需要设置SqlTransaction
------解决方案--------------------
cmd.Transaction = trans;
------解决方案--------------------
写在SqlTransaction trans = sqlCon.BeginTransaction(); //开始执行事务后面
------解决方案--------------------
http://msdn.microsoft.com/zh-cn/library/system.data.sqlclient.sqltransaction(v=VS.80).aspx看msdn的例子
------解决方案--------------------

C# code

try
  {
  cmd.Transaction = trans; //设置事物
  foreach (DataRow dr in dt.Rows)
  {
  cmd.CommandText = "update tb_2 set val = @val where id = @id";
  cmd.Parameters.Add("@id", SqlDbType.Int);
  cmd.Parameters["@id"].Value = Convert.ToInt32(dr["id"].ToString());
  cmd.Parameters.Add("@val", SqlDbType.Int);
  cmd.Parameters["@val"].Value = Int32.Parse(dr["val"].ToString());
  cmd.ExecuteNonQuery();
  cmd.Parameters.Clear();//注意要清空参数
  }
  trans.Commit();
  }
  catch(Exception ex)
  {
  Console.WriteLine(ex.ToString());
  trans.Rollback();
  }
  finally
  {
  sqlCon.Close();
  trans.Dispose();
  sqlCon.Dispose();
  }