Question

任何人都知道如何通过使用控制器以某种格式返回JSON对象，这样它将以指定的顺序显示数据，如下所示。我尝试在线研究解决方案，发现其中大多数使用控制器，但是我对他们提供的解决方案感到困惑。

当前结果

{
    "Table:" [
        {
            "ED_Name": "Ang Mo Kio GRC",
            "GARO_Name": "Central CDC"
        },
        {
            "ED_Name": "Bishan-Toa Payoh GRC",
            "GARO_Name": "Central CDC"
        },
    ]
}

预期结果

{
    "Table": [
        {
            "Central CDC": ["Ang Mo Kio GRC"]
        },
        {
            "North-East CDC": ["Pasir Ris - Punggol GRC", "Tampines GRC"]
        }
    ]
}

控制器代码

public class GAROController : ApiController
{

    Database_Access_Data.db dblayer = new Database_Access_Data.db();

    [System.Web.Http.HttpGet]
    [System.Web.Http.Route("api/GARO/GetGAROList")]
    public DataSet CheckLockedOut()
    {
        DataSet ds = dblayer.GetGAROList();
        return ds;
    }
}

以及从数据库中调用存储过程的代码：

public DataSet GetGAROList()
{
    SqlCommand com = new SqlCommand("GetCDC", con);
    com.CommandType = CommandType.StoredProcedure;
    SqlDataAdapter da = new SqlDataAdapter(com);
    DataSet ds = new DataSet();
    da.Fill(ds);

    return ds;
}

用于从数据库检索数据的存储过程

  /****** Object:  StoredProcedure [dbo].[GetCDC]    Script Date: 4/12/2018 
  5:30:01 PM ******/
 SET ANSI_NULLS ON
 GO
 SET QUOTED_IDENTIFIER ON
 GO
 ALTER PROCEDURE [dbo].[GetCDC]
  AS 
  BEGIN 
  Select E.Name AS ED_Name, G.Name AS GARO_Name
  From ElectoralDivision E
  INNER JOIN GARO G ON G.ID = E.GAROID
  ORDER BY G.Name, E.Name
  END

Answer 1

您需要创建自定义json转换器，将每个属性转换为您的自定义格式。

public class CustomJsonConverter : JsonConverter
{
    public override bool CanRead
    {
        get { return false; }
    }

    public override bool CanConvert(Type objectType)
    {
        return true;
    }

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        throw new NotImplementedException("Unnecessary because CanRead is false. The type will skip the converter.");
    }

    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        JArray jArray = new JArray();
        if (value != null)
        {
            foreach (var item in (Dictionary<string, List<string>>)value)
            {
                JObject jObject = new JObject();
                jObject.Add(new JProperty(item.Key, JArray.FromObject(item.Value)));
                jArray.Add(jObject);
            }
        }

        JObject jMainObject = new JObject();
        jMainObject.Add(new JProperty("Table", jArray));
        jMainObject.WriteTo(writer);
    }
}

您可以像上面那样使用上面的转换器

//Your DataSet filled with stored procedure result.
DataSet ds = dblayer.GetGAROList();

//Populate DataTable from above DataSet
DataTable dt = ds.Tables[0];

//Project your data from DataTable to Dictionary
var result = (from row in dt.AsEnumerable()
              group row by row.Field<string>("GARO_Name") into grp
              select new
              {
                  GARO_Name = grp.Key,
                  ED_Name = grp.Select(x => x.Field<string>("ED_Name")).ToList()
              }).ToDictionary(x => x.GARO_Name, x => x.ED_Name);

//Use above Converter 
string json = JsonConvert.SerializeObject(result, new CustomJsonConverter());

//Print formatted json to console
Console.WriteLine(JObject.Parse(json));

输出：

https://en.wikipedia.org/wiki/Collatz_conjecture

调整控制器以将JSON对象返回为特定格式

1 个答案: