SqlConnection conn = new SqlConnection(conStr);
// 如果是关闭状态if (conn.State == System.Data.ConnectionState.Closed) { conn.Open();}
SqlConnection conn = new SqlConnection(conStr);
// 如果是关闭状态if (conn.State == System.Data.ConnectionState.Closed) { conn.Open();}原文：https://www.cnblogs.com/tylerflyn/p/8267331.html