从方法返回多个值。 [英] Return multiple value from a method.

问题描述

我试图从这个c＃方法返回2个输出参数，并返回第二个ruturn参数的错误。



我尝试过：



public string getEMails（string staffid）

{

using（OracleConnection OracleConn = new OracleConnection） （或））

{

OracleConn.Open（）;

尝试

{

query =SELECT uetc.team_codes，LPAD（papf.employee_number，5,0）staff_id，papf.full_name full_name AND papf.employee_number = @employee_number;

OracleCommand OraC = new OracleCommand（查询，OracleConn）;

OraC.CommandType = CommandType.Text;

OraC.Parameters.Add（新的OracleParameter（employee_number，OracleDbType.Varchar2））。Value = staffid;

//OraC.Parameters.Add(new OracleParameter（SESSION_ID，OracleDbTy） pe.Varchar2））。Value = SessionID;

//OraC.Parameters.Add（new OracleParameter（V_RESULT，OracleDbType.Varchar2,32767））。Direction = ParameterDirection.Output;





// OracleDataReader dr = OraC.ExecuteNonQuery（）;

OracleDataReader dr = OraC.ExecuteReader（）;

while（dr.Read（））

{

SupervisorEmail = dr [EMAIL_ADDRESS_1]。ToString（）;

StaffEmail = dr [EMAIL_ADDRESS]。ToString（）;

string id = dr [STAFF_ID]。ToString（）;



}



}

catch（例外情况）

{



ex.Message.ToString（）;

}

终于

{

OracleConn.Close（）;

}

返回SupervisorEmail;

返回StaffEmail;



}

}

im trying to return 2 output parameters from this c# method and it returning an error for the second ruturn parameter.

What I have tried:

public string getEMails(string staffid)
{
using (OracleConnection OracleConn = new OracleConnection(or))
{
OracleConn.Open();
try
{
query = "SELECT uetc.team_codes, LPAD (papf.employee_number, 5, 0) staff_id,papf.full_name full_name AND papf.employee_number = @employee_number";
OracleCommand OraC = new OracleCommand(query, OracleConn);
OraC.CommandType = CommandType.Text;
OraC.Parameters.Add(new OracleParameter("employee_number", OracleDbType.Varchar2)).Value = staffid;
//OraC.Parameters.Add(new OracleParameter("SESSION_ID", OracleDbType.Varchar2)).Value = SessionID;
//OraC.Parameters.Add(new OracleParameter("V_RESULT", OracleDbType.Varchar2, 32767)).Direction = ParameterDirection.Output;


//OracleDataReader dr = OraC.ExecuteNonQuery();
OracleDataReader dr = OraC.ExecuteReader();
while (dr.Read())
{
SupervisorEmail = dr["EMAIL_ADDRESS_1"].ToString();
StaffEmail = dr["EMAIL_ADDRESS"].ToString();
string id = dr["STAFF_ID"].ToString();

}

}
catch (Exception ex)
{

ex.Message.ToString();
}
finally
{
OracleConn.Close();
}
return SupervisorEmail;
return StaffEmail;

}
}

推荐答案

一个方法只能返回一个值：即所有定义允许的值。

要返回多个值，要么返回需要使用 out 或 ref 参数：

A method can only return one value: that is all the definition allows.
To return multiple values, you either need to use an out or ref parameter as well:

public string getEMails(string staffid, out staffEmail)
   {
   ...
   staffEmail = ... ;
   return SupervisorEmail;
   }

public string getEMails(string staffid, ref staffEmail)
   {
   ...
   staffEmail = ... ;
   return SupervisorEmail;
   }

并调用它将适当的变量传递给方法：

And call it passing the appropriate variable to the method:

string staffEmail;
string supEmail = getEMails("00001", out staffEmail);

string staffEmail = "none";
string supEmail = getEMails("00001", ref staffEmail);

或者，你可以创建一个容器类，它包含您的参数，并返回：

Or, you could create a "container class" which holds both your parameters, and return that:

public class EMails
   {
   string Staff {get; set}
   string Supervisor {get; set;}
   }
...
public EMails getEMails(string staffid)
   {
   ...
   Emails em = new Emails;
   em.Staff = StaffEmail;
   em.Supervisor = SupervisorEmail;
   return em;
   }

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