javascript - 使用 WebAPI Controller 序列化复杂的 json 对象

Question

我是 angularjs 和 ASP.NET webapi 的新手。我正在处理一些要求，我的基表如下所示

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

我为这些表创建了两个模型类(类(class)和查找)。我如何使用 webapi Controller 方法 public HttpResponseMessage getData(...)

生成如下所示的 JSon 数据

我需要如下所示的结果 JSON 数据

    $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" }
        ]
    }
.
.
.
];

请查看此链接以获得更好的理解 https://plnkr.co/edit/73oA3rsrre8gqYX9V25W?p=preview

那么getData(生成JSon数据)这两个方法怎么写呢。谁能帮我在 ASP.NET 中序列化这个结构

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

Answer 1

假设您已使用以下实体为 SQL 表建模:

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; }
}

下一步是定义一个 View 模型来表示您要序列化的结构:

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; }
}

然后在您的 Controller 中，您可以从数据库中获取实体并从中填充 View 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);
        }
    }
}