从 JsonResult 中删除 ContentEncoding

Question

我想从数据表中生成 json，我已经尝试过了

public static JsonResult ConvertFromDataTable(DataTable dataTable)
    {
        var result = new List<dynamic>();
        foreach (DataRow row in dataTable.Rows)
        {
            dynamic dyn = new ExpandoObject();
            foreach (DataColumn column in dataTable.Columns)
            {
                var dic = (IDictionary<string, object>)dyn;
                dic[column.ColumnName] = row[column];
            }
            result.Add(dyn);
        }

        string _json = JsonConvert.SerializeObject(result);

        var resultJSON = new JsonResult
        {
            Data = JsonConvert.DeserializeObject(_json),
            JsonRequestBehavior = JsonRequestBehavior.AllowGet
        };

        return resultJSON;
    }

但结果总是在我的 json 上有“ContentEncoding”、“ContentType”，

{
"ContentEncoding": null,
"ContentType": null,
"Data": [
    {
        "Name": "Steve",
        "Age": "30",
        "Photo": "steve.png",
        "Gender": "Male"
    },
    {
        "Name": "Sarah",
        "Age": "19",
        "Photo": "sarah.png",
        "Gender": "Female"
    }
],
"JsonRequestBehavior": 0,
"MaxJsonLength": null,
"RecursionLimit": null
}

我只需要我的 json 中的“数据”，可以删除它吗？

Answer 1

这只是你如何做到这一点的一个例子。

我更喜欢这种方式，因为：

1. 当您返回强类型数据时，您的控制器更具可读性。您（和您的队友）很清楚 - 将从该控制器返回哪些数据。

2. 我建议尽可能避免使用动态类型。您可以在 When should one use dynamic keyword in c# 4.0?

   阅读更多相关信息

代码：

public class Person
{
    public string Name { get; set; }
    public string Age { get; set; }
    public string Photo { get; set; }
    public string Gender { get; set; }
}

public static List<Person> ConvertFromDataTable(DataTable dataTable)
{
    var result = new List<Person>();

    foreach (DataRow row in dataTable.Rows)
    {
        var person = new Person();

        foreach (DataColumn column in dataTable.Columns)
        {
            switch (column.ColumnName)
            {
                case "Name":
                    person.Name = row[column].ToString();break;

                case "Age":
                    person.Age = row[column].ToString(); break;

                case "Photo":
                    person.Name = row[column].ToString(); break;

                case "Gender":
                    person.Name = row[column].ToString(); break;
            }
        }

        result.Add(person);
    }

    return result;
}

//your api method there
public List<Person> GetPersons()
{
    DataTable dt = new DataTable();
    //here you populate your DataTable
    return ConvertFromDataTable(dt);
}

此外，您可以进行一些通用扩展来将 DataTable 转换为类型化对象，您可以在此处看到一个示例：How to Convert DataTable to Generic List in C#

Answer 2

您可以使用 Newtonsoft JSON 库轻松转换它

    DataTable table = new DataTable();
    DataColumn idColumn = new DataColumn("id", typeof(int));
    idColumn.AutoIncrement = true;

    DataColumn itemColumn = new DataColumn("item");
    table.Columns.Add(idColumn);
    table.Columns.Add(itemColumn);


    for (int i = 0; i < 2; i++)
    {
        DataRow newRow = table.NewRow();
        newRow["item"] = "item " + i;
        table.Rows.Add(newRow);
    }

    //produces formatted string, to avoid it omit the parameter from the method call
    string json = JsonConvert.SerializeObject(table, Formatting.Indented);
    

输出

[
  {
    "id": 0,
    "item": "item 0"
  },
  {
    "id": 1,
    "item": "item 1"
  }
]

请参考小提琴here

参考https://www.newtonsoft.com/json/help/html/SerializeDataSet.htm