返回任何類型的C＃

我有一個場景，我必須根據條件返回不同類型的對象。返回任何類型的C＃

爲此，我在c＃4.0中使用了dynamic返回類型。

但我無法做到這一點。

public dynamic ValidateUser(string UserName, string Password) 
{ 
    string Result = string.Empty; 

    Employees clsEmployee = new Employees(); 
    Customer clsCustomer = new Customer(); 

    sqlConnection = new SqlConnection(Connection()); 
    command = new SqlCommand("dbo.usp_ValidateUser", sqlConnection); 
    command.CommandType = CommandType.StoredProcedure; 
    command.Parameters.Add("@Username", SqlDbType.VarChar).Value = UserName; 
    command.Parameters.Add("@Password", SqlDbType.VarChar).Value = Password; 
    sqlConnection.Open(); 

    SqlParameter newSqlParam = new SqlParameter(); 
    newSqlParam.ParameterName = "@Result"; 
    newSqlParam.SqlDbType = SqlDbType.NVarChar; 
    newSqlParam.Direction = ParameterDirection.Output; 
    newSqlParam.Size = 50; 
    command.Parameters.Add(newSqlParam); 

    SqlDataReader dr = command.ExecuteReader(); 
    Result = command.Parameters["@Result"].Value.ToString(); 

    if (Result == "Employee") 
    { 
     while (dr.Read()) 
     { 
      clsEmployee.EmployeeId = (int)dr["EmployeeId"]; 
      clsEmployee.EmployeeName = (string)dr["EmployeeName"]; 
      clsEmployee.DepartmentName = (string)dr["DepartmentName"]; 
      clsEmployee.RoleName = (string)dr["RoleName"]; 
     }  
     return clsEmployee; 
    } 
    else if (Result == "Customer") 
    { 
     while (dr.Read()) 
     { 
      clsCustomer.CustomerId = (int)dr["CustomerId"]; 
      clsCustomer.CustomerName = (string)dr["CustomerName"]; 
      clsCustomer.CustomerEmail = (string)dr["CustomerEmail"]; 
      clsCustomer.CustomerMobile = (string)dr["CustomerMobile"]; 
     } 
     return clsCustomer; 
    } 


    //How to return??? 
}

當我嘗試的條件內返回它拋出我

並非所有的代碼路徑返回值」的錯誤。

任何解決方案？

來源

2013-09-28 iamCR

爲什麼不把認證分成單獨的一個類，或者至少返回'IPerson'？「動態」幾乎從來都不是正確的解決方案。 –

而不是有最後的'else'語句，只是'返回結果;' –

我強烈懷疑這不是你的實際代碼，否則你不會得到那個錯誤信息。我懷疑你最後的'else'實際上是一個'else if'或類似的東西。 –

只需卸下else部分：

else if (Result == "Customer") 
{ 
    while (dr.Read()) 
    { 
     clsCustomer.CustomerId = (int)dr["CustomerId"]; 
     clsCustomer.CustomerName = (string)dr["CustomerName"]; 
     clsCustomer.CustomerEmail = (string)dr["CustomerEmail"]; 
     clsCustomer.CustomerMobile = (string)dr["CustomerMobile"]; 
    } 
    return clsCustomer; 
} 
return Result;

來源

2013-09-28 07:03:05

Santhosh，

這不是處理不同類型的適當方式。你可以考慮實現一個接口來實現這一點。這使得更多的可讀性和更多的可擴展性。我相信你正在開發一個支持代碼，這樣你可能會對實現新的實現有所限制。

我想你可以這樣

public object ValidateUser(string UserName, string Password) 
{ 
    object retVal= null; 
    string Result = String.Empty; 

    Employees clsEmployee = new Employees(); 
    Customer clsCustomer = new Customer(); 

    // get the data 
    Result = command.Parameters["@Result"].Value.ToString(); 

    if (Result == "Employee") 
    { 
     while (dr.Read()) 
     { 
      clsEmployee.EmployeeId = (int)dr["EmployeeId"]; 
      clsEmployee.EmployeeName = (string)dr["EmployeeName"]; 
      clsEmployee.DepartmentName = (string)dr["DepartmentName"]; 
      clsEmployee.RoleName = (string)dr["RoleName"]; 
     } 

     retVal=clsEmployee; 
    } 
    if (Result == "Customer") 
    { 
     while (dr.Read()) 
     { 
      clsCustomer.CustomerId = (int)dr["CustomerId"]; 
      clsCustomer.CustomerName = (string)dr["CustomerName"]; 
      clsCustomer.CustomerEmail = (string)dr["CustomerEmail"]; 
      clsCustomer.CustomerMobile = (string)dr["CustomerMobile"]; 
     } 

     retVal=clsCustomer; 
    } 
    retVal=Result; 
    return retVal; 
    }

改變我認爲這將消除當前的問題。

來源

2013-09-28 07:14:35 kbvishnu

switch (Result) 
{ 
    case "Employee": 
    { 
     ... 
     return ... 
    } 
    case "Customer": 
    { 
     ... 
     return .... 
    } 
    default: 
     return Result; 
}

來源

2013-09-28 07:23:55 abatishchev

返回任何類型的C＃

回答

相關問題