string connStr = ConfigurationManager.ConnectionStrings["dbConnStr"].ConnectionString; Stopwatch sp = new Stopwatch(); sp.Start(); for (int i = 0; i < 1000; i++) { SqlConnection conn = new SqlConnection(connStr); conn.Open(); conn.Close(); } sp.Stop(); MessageBox.Show(sp.Elapsed.ToString()); Close(),关闭连接,SqlConnection对象还在内存,就是说还能Open() dispose(),SqlConnection都没有了,这个东西不复存在,必须重新创建在能使用