c# - Angular 6/C#/MVC 以 Json Array of Array 的形式从 Controller 动态返回 JsonResult

Question

我正在尝试在 Angular 6 应用程序中将大量数据集导出到 Excel。为此，我正在使用 XLSX 和文件保存，如前所述: https://medium.com/@madhavmahesh/exporting-an-excel-file-in-angular-927756ac9857

问题是字段可能会不时更改，所以我需要一些动态的东西(不想指定列名)。为此，我找到了一个很好的例子: Binding Json data to a table in mvc 4

但是，我没有得到正确格式的数据。我需要像数组数组这样的东西。我假设返回类型应该是 async Task<JsonResult>在那种情况下，但不确定如何使其工作。我附上了两张图片 - 我得到的结果

和预期结果

这是引用示例中的代码。对 GetMyData 的存储过程调用，使用 SqlAdapter，无需指定字段名称

 public JsonResult GetValue()
    {
        JsonResult json = new JsonResult();
        DataSet ds = GetMyData(); 
       /*LoadDoctordetailsNew is method where i get data from database and convert
          to dataset.It returns a dataset*/
        string returnData = GetJson(ds.Tables[0]);
        json.JsonRequestBehavior = JsonRequestBehavior.AllowGet;
        json.Data = returnData;            
        return json;
    }

    public static string GetJson(DataTable dt)
    {
        System.Web.Script.Serialization.JavaScriptSerializer serializer =
           new System.Web.Script.Serialization.JavaScriptSerializer();
        List<Dictionary<string, object>> rows =
           new List<Dictionary<string, object>>();
        Dictionary<string, object> row = null;

        foreach (DataRow dr in dt.Rows)
        {
            row = new Dictionary<string, object>();
            foreach (DataColumn col in dt.Columns)
            {
                row.Add(col.ColumnName, dr[col]);
            }
            rows.Add(row);
        }
        return serializer.Serialize(rows);
    }

public static DataSet GetMyData()
        {
            try
            {
                using (SqlConnection connection = Connection.GetConnection())
                {
                  SqlDataAdapter da = new SqlDataAdapter("dbo.MySQLStoredproc", connection);
                    da.SelectCommand.CommandType = CommandType.StoredProcedure;
                    DataSet ds = new DataSet();
                    da.Fill(ds);
                    return ds;
                }
            }
            catch (Exception ex)
            {
                throw;
            }
        }

请指导!

附言

此技术使用 Dapper。它按需要(数组的数组)格式返回数据，但在对象中我们必须指定列名，这将是硬编码，因此，我不能使用

public static IEnumerable<Object> GetMyData()
        {

            var strQuery = @"[dbo].[Myproc]";        
            IEnumerable< Object > items = new List<Object>(0);
            var p = new DynamicParameters();

            using (SqlConnection con = Connection.GetConnection())
            {
                items = con.Query<Object>(strQuery, param: p, commandTimeout: 120, commandType: System.Data.CommandType.StoredProcedure);
            }
            return items;
        }

从 MVC Controller 调用

[HttpPost]
public async Task<JsonResult> SelectMyData()
{
    var task = Task.Run(() => Request.GetMyData());

    var retData = await task;
    return new JsonResult
    {
        ContentType = "application/json",
        Data = retData,
        JsonRequestBehavior = JsonRequestBehavior.AllowGet,
        MaxJsonLength = int.MaxValue
    };
}

Answer 1

您应该返回 List<Dictionary<string, object>>而不是 string .你不需要 Serialize JsonResult 将处理的数据

public JsonResult GetValue()
{
    JsonResult json = new JsonResult();
    DataSet ds = GetMyData(); 
   /*LoadDoctordetailsNew is method where i get data from database and convert
      to dataset.It returns a dataset*/
    json.Data = GetJson(ds.Tables[0]);
    json.JsonRequestBehavior = JsonRequestBehavior.AllowGet;
    return json;
}

public static List<Dictionary<string, object>> GetJson(DataTable dt)
{
    List<Dictionary<string, object>> rows =
       new List<Dictionary<string, object>>();
    Dictionary<string, object> row = null;

    foreach (DataRow dr in dt.Rows)
    {
        row = new Dictionary<string, object>();
        foreach (DataColumn col in dt.Columns)
        {
            row.Add(col.ColumnName, dr[col]);
        }
        rows.Add(row);
    }
    return rows;
}