str="Data Source=ip; Network Library=DBMSSOCN; Initial Catalog=数据库; User ID=sa; Password=xx"
string str = ConfigurationManager.AppSettings["con_MES"]; try { using (SqlConnection conn = new SqlConnection(str)) { conn.Open(); if (conn.State == ConnectionState.Open) { MessageBox.Show("连接成功"); } } } catch (Exception ex) { MessageBox.Show(ex.Message); }