Question

我有

public jsonresult update(studentinfo s)
{

  for(i=0;i>0;i++)
  {
     var x = // i am getting some x so i am checking again 

     if( x != null)
      {
        var updateuser = student.update(s.student,"","");
        **return json(updateuser.ToString());** // if i keep it here i am getting exceptoin  saying not all code paths return value bec this return i can not keep it out for loop bec each and evary updateuser i need to return json..
      }
  }

}

如何克服这类事情？

Answer 1

您使用什么语言编写代码？你发布的内容看起来不像我所知道的任何.NET语言。以下是控制器操作在C＃中的外观（假设这是您正在使用的语言）：

public ActionResult Update(StudentInfo s)
{
    // create some collection that will contain all updated users
    var updatedUsers = new List<StudentInfo>();

    // Revise the loop as it is absolutely not clear from your code
    // what you are trying to do. The way you wrote the loop it will 
    // never execute - for(int i=0; i>0; i++)
    for (int i = 0; i < 5; i++)
    {
        var updatedUser = student.Update(s.student, "", "");
        updatedUsers.Add(updatedUser);
    }

    // return the list of updated users outside the loop so that the compiler 
    // doesn't complain about paths of the method not returning a value
    return Json(updatedUsers);
}

Answer 2

如果我理解正确，您想要返回一组用户。 'return'关键字不起作用。您需要立即返回整个集合。

如何处理这类事情。使用asp.net mvc

2 个答案: