C# 返回C中的任何类型#

我有一个场景，我必须根据条件返回不同类型的对象

为此，我在c#4.0中使用了

动态
返回类型

但我没能做到

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???
}

当我试图回到状态时，它会把我抛在身后

并非所有代码路径返回值都有“错误”

有什么解决方案吗？
只需删除
其他部分
即可：

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;

桑托什

这不是处理不同类型的正确方法。您可以考虑实现一个接口来实现这一点。这使得可读性更强，扩展性更强。我相信您正在开发一个支持代码，因此您可能会有实现新实现的限制

我想你可以这样改变

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;
    }

我认为这将消除当前的问题。
为什么不将身份验证从总体中拆分为一个单独的类，或者至少返回
IPerson
dynamic
几乎从来都不是正确的解决方案。与其使用最后一个
else
语句，不如使用
返回结果我强烈怀疑这不是您的实际代码，否则您就不会收到错误消息。我怀疑你最后的
else
实际上是一个
else if
或类似的东西。正如Tim所建议的，我强烈建议使用Interface或某个父类，可能是一个用户类型的类，后来被继承为customer或Employee，并且总是返回用户类对象。如果结果是意外的，您真的想只返回一个字符串吗？我觉得这很奇怪。和蒂姆一样，我也质疑这里的设计。
switch (Result)
{
    case "Employee":
    {
        ...
        return ...
    }
    case "Customer":
    {
        ...
        return ....
    }
    default:
        return Result;
}