使用WebAPI控制器序列化複雜的json對象

Question

我是angularjs和ASP.NET webapi的新手。我工作的一些要求，其中我的基表如下

CurriculumID SubjectArea CourseNumber 
------------ ----------- ------------ 
303  GHIJ  101 
304  ABCD  102 
305  MNPQ  103 
306  WXYZ  104 

lookupId lookupValue 
-------- ----------- 
1  Very Useful 
2  Somewhat Useful 
3  Not Useful 
4  Not Applicable 
5  Elsewhere 

我已經創建了這些表兩型類（當然和查找）。我怎樣才能如下genarate JSON數據備份使用的WebAPI控制器的方法public HttpResponseMessage getData(...)

我需要一個像下面

$scope.questions = [ 
    { 
     "CurriculumID": "303", "SubjectArea": "GHIJ", "CourseNumber": "101", "answers": [ 
     { "lookupValue": "Very Useful","lookupId":"1" }, 
     { "lookupValue": "Somewhat Useful", "lookupId": "2" }, 
     { "lookupValue": "Not Useful", "lookupId": "3" }, 
     { "lookupValue": "Not Applicable", "lookupId": "4" }, 
     { "lookupValue": "Elsewhere", "lookupId": "5" } 
     ] 
    }, 
    { 
     "CurriculumID": "304", "SubjectArea": "ABCD", "CourseNumber": "102", "answers": [ 
     { "lookupValue": "Very Useful","lookupId":"1" }, 
     { "lookupValue": "Somewhat Useful", "lookupId": "2" }, 
     { "lookupValue": "Not Useful", "lookupId": "3" }, 
     { "lookupValue": "Not Applicable", "lookupId": "4" }, 
     { "lookupValue": "Elsewhere", "lookupId": "5" } 
     ] 
    } 
. 
. 
. 
]; 

請看這個鏈接爲了更好地理解所產生的JSON數據 https://plnkr.co/edit/73oA3rsrre8gqYX9V25W?p=preview

那麼如何編寫兩個方法getData（來生成JSon數據）。請誰能幫助我在ASP.NET序列化此結構

https://plnkr.co/edit/73oA3rsrre8gqYX9V25W?p=preview

Answer 1

讓我們假設你有你的模型SQL表與以下實體：

public class Question 
{ 
    [Key] 
    public int CurriculumID { get; set; } 

    public string SubjectArea { get; set; } 

    public int CourseNumber { get; set; } 
} 

public class Rating 
{ 
    [Key] 
    public int LookupId { get; set; } 

    public string LookupValue { get; set; } 
} 

下一步將是確定一個視圖模型，將代表你想要序列化的結構：

public class QuestionViewModel 
{ 
    public int CurriculumID { get; set; } 

    public string SubjectArea { get; set; } 

    public int CourseNumber { get; set; } 

    public IList<RatingViewModel> Answers { get; set; } 
} 

public class RatingViewModel 
{ 
    public int LookupId { get; set; } 

    public string LookupValue { get; set; } 
} 

然後在你的控制器，你可以獲取ent從您的數據庫中獲取數據並從它們填充視圖模型：

public class QuestionsController: ApiController 
{ 
    [HttpGet] 
    [Route("api/questions")] 
    public IHttpActionResult Get() 
    { 
     using (var db = new MyDbContext()) 
     { 
      IList<Rating> ratings = db.Ratings.ToList(); 
      IList<Question> questions = db.Questions.ToList(); 
      IList<QuestionViewModel> result = questions.Select(q => new QuestionViewModel 
      { 
       CurriculumID = q.CurriculumID, 
       SubjectArea = q.SubjectArea, 
       CourseNumber = q.CourseNumber, 
       Answers = ratings.Select(r => new RatingViewModel 
       { 
        LookupId = r.LookupId, 
        LookupValue = r.LookupValue, 
       }).ToList(), 
      }).ToList(); 

      return this.Ok(result); 
     } 
    } 
}