关于方法的参数问题

Question

这个三个参数怎么传出来，我怎么写的不对啊！忘知情的老大们指导一下.
                    这里报错
                        ↓
public string SelectNetBarInfo(string contName, out string operatorPwd, out string publicName, out string publicPwd)
        {
            try
            {
                sqlconn = new SqlConnection("server=192.168.1.9;uid=gsvnet;pwd=gsvnet;database=GSVNetCenter");
                selcmd = new SqlCommand();
                selcmd.Connection = sqlconn;
                selcmd.CommandText = "UpdateUserInfo";
                selcmd.CommandType = CommandType.StoredProcedure;
                selcmd.Parameters.AddWithValue("@LoginName", contName);
                selcmd.Parameters.Add("@LoginPwd", SqlDbType.VarChar, 20).Direction = ParameterDirection.Output;
                selcmd.Parameters.Add("@PublicUserName", SqlDbType.VarChar, 20).Direction = ParameterDirection.Output;
                selcmd.Parameters.Add("@PublicUserPwd", SqlDbType.VarChar, 20).Direction = ParameterDirection.Output;
                if (sqlconn.State != ConnectionState.Closed)
                {
                    sqlconn.Close();
                }
                sqlconn.Open();
                selcmd.ExecuteNonQuery();
                operatorPwd = selcmd.Parameters["@LoginPwd"].Value.ToString();
                publicName = selcmd.Parameters["@PublicUserName"].Value.ToString();
                publicPwd = selcmd.Parameters["@PublicUserPwd"].Value.ToString();
            }
            catch (Exception ex)
            {
                return ex.Message;//这里报错
            }
            finally
            {
                sqlconn.Close();
            }
        }

Answer 1

//连接关闭后再使用其返回值，而且楼主没说出错信息是什么
public string SelectNetBarInfo(string contName, out string operatorPwd, out string publicName, out string publicPwd)
        {
try{
                sqlconn = new SqlConnection("server=192.168.1.9;uid=gsvnet;pwd=gsvnet;database=GSVNetCenter");
                selcmd = new SqlCommand();
                selcmd.Connection = sqlconn;
                selcmd.CommandText = "UpdateUserInfo";
                selcmd.CommandType = CommandType.StoredProcedure;
                selcmd.Parameters.AddWithValue("@LoginName", contName);
                selcmd.Parameters.Add("@LoginPwd", SqlDbType.VarChar, 20).Direction = ParameterDirection.Output;
                selcmd.Parameters.Add("@PublicUserName", SqlDbType.VarChar, 20).Direction = ParameterDirection.Output;
                selcmd.Parameters.Add("@PublicUserPwd", SqlDbType.VarChar, 20).Direction = ParameterDirection.Output;
                if (sqlconn.State != ConnectionState.Closed)
                {
                    sqlconn.Close();
                }
                sqlconn.Open();
                selcmd.ExecuteNonQuery();
sqlconn.Close();
                operatorPwd = selcmd.Parameters["@LoginPwd"].Value.ToString();
                publicName = selcmd.Parameters["@PublicUserName"].Value.ToString();
                publicPwd = selcmd.Parameters["@PublicUserPwd"].Value.ToString();
            }
            catch (Exception ex)
            {
                return ex.Message;
            }
        }

Answer 2

public string SelectNetBarInfo
要返回 string

Answer 3

1。
这个问题白问了，什么错都不说，编译错误，还是运行时错误，是调用错此函数发生误吗？
也不会贴错误信息，堆栈信息之类，就是红色那一片文字
2。
此函数声明具有 string 类型的返回值，故你需要确保函数结束时，返回一个 string ，但你的代码，只有当 catch (Exception ex)
            {
                return ex.Message;
            }
才返回，故
catch (Exception ex)
            {
                return ex.Message;
            }
        }>>>catch (Exception ex)
            {
                return ex.Message;
            }
        }
return "OK"; // 执行成功，返回何值你自己定义3。
你的 finally 内能访问到 sqlconn 吗？
4。
将会发生异常的代码部分放到 try - catch 中5。
问题太多了，重写一个public string SelectNetBarInfo(string contName, out string operatorPwd, out string publicName, out string publicPwd)
        {
            //
                sqlconn = new SqlConnection("server=192.168.1.9;uid=gsvnet;pwd=gsvnet;database=GSVNetCenter");
                selcmd = new SqlCommand();
                selcmd.Connection = sqlconn;
                selcmd.CommandText = "UpdateUserInfo";
                selcmd.CommandType = CommandType.StoredProcedure;
                selcmd.Parameters.AddWithValue("@LoginName", contName);
                selcmd.Parameters.Add("@LoginPwd", SqlDbType.VarChar, 20).Direction = ParameterDirection.Output;
                selcmd.Parameters.Add("@PublicUserName", SqlDbType.VarChar, 20).Direction = ParameterDirection.Output;
                selcmd.Parameters.Add("@PublicUserPwd", SqlDbType.VarChar, 20).Direction = ParameterDirection.Output;
 
            // 
            try  {
                
                sqlconn.Open();
                selcmd.ExecuteNonQuery();
                operatorPwd = selcmd.Parameters["@LoginPwd"].Value.ToString();
                publicName = selcmd.Parameters["@PublicUserName"].Value.ToString();
                publicPwd = selcmd.Parameters["@PublicUserPwd"].Value.ToString();
            }
            catch (Exception ex)
            {
                return ex.Message;//这里报错
            }
            finally
            {
                if (sqlconn.State != ConnectionState.Closed)
                {
                    sqlconn.Close();
                }
            }
            
            return "OK";            
        }

Answer 4

你的程序错在
            finally
            {
                sqlconn.Close();
            }
 吧，你在出错时，返回，后面的finally是必须执行的啊