jQuery调用Webservice传递json数组的方法

//JQuery 调用webService导入数据
function LoadData() {
    var studentData = CollectionData();
    $.ajax({
      url: "ImportDataService.asmx/ImportStu",
      type: "post",
      contentType: "application/json;charset=utf-8",
      dataType: "json",
      data: "{'students':[{'name':'KoBe ','sex':'boy','age':'20'},{'name':'Mary','sex':'girl','age':'19'}]}",
      success: function(result) {
        alert(result.d);
      },
      error: function(e) {
        alert(e.responseText);
      }
    });
}

/// <summary>
///
/// </summary>
/// <param name="students"></param>
/// <returns></returns>
[WebMethod]
[ScriptMethod(ResponseFormat=ResponseFormat.Json)]
public string ImportStu(Dictionary<string,string> []students)
{
  if (students.Length == 0)
  {
    return "没有任何数据!";
  }
  else
  {
    try
    {
      foreach (Dictionary<string, string> stu in students)
      {
        //构造一个新的Student对象。
        Student student = new Student();
        //为新构造的Student对象属性赋值。
        foreach (string key in stu.Keys)
        {
          switch (key)
          {
            case "name":
              student.Name = stu[key];
              break;
            case "sex":
              student.Sex = stu[key];
              break;
            case "age":
              int age;
              if (Int32.TryParse(stu[key], out age))
              {
                student.Age = age;
              }
              else
              {
                student.Age = 0;
              }
              break;
            default:
              break;
          }
        }
      }
      return "导入学生成功!";
    }
    catch
    {
      throw new Exception("导入学生失败!");
    }
  }
}