使用Json.Net转换DataTable时，使用Json的格式无效 [英] Invalid format with Json when converting DataTable with Json.Net

问题描述

我正在尝试使用Newtonsoft.JSON将DataTable转换为JSON，但发现输出不是ExtJS网格和图表所期望的.

I'm trying to convert DataTable to JSON using Newtonsoft.JSON but found that the output is not what ExtJS grid and chart would expect.

我的代码是

string output = JsonConvert.SerializeObject(dt, Formatting.Indented,
                            new JsonSerializerSettings
                            {
                                ReferenceLoopHandling = ReferenceLoopHandling.Ignore
                            });

这将返回Json字符串为

and this returns Json string as

"[{\"DAYDATE\":\"2012-05-22T00:15:00\",\"SERIES1\":3.65}]"

如果我删除'\'并在双引号和结束双引号中使用ExtJS，则效果很好.

If I remove '\' and start and end double quotes it works fine with ExtJS.

我还尝试将日期格式更改为更多JSON'y

I also tried changing date format to more JSON'y

string javascriptJson = JsonConvert.SerializeObject(entry, new JavaScriptDateTimeConverter());

产生

"[{\"DAYDATE\":new Date(1337642100000),\"SERIES1\":3.65}]"

仍然没有运气

推荐答案

您的JSON似乎已经被双重序列化了.尽管您没有显示完整的控制器代码，但我猜测您正在执行以下操作:

It looks like your JSON is getting double serialized. Although you did not show your full controller code, I'm guessing that you are doing something like this:

    public ActionResult GetDataTable()
    {
        // (... code to build data table omitted for brevity ...)

        // Serialize data table using Json.Net to avoid circular reference error
        string output = JsonConvert.SerializeObject(dt,
            new JsonSerializerSettings
            {
                ReferenceLoopHandling = ReferenceLoopHandling.Ignore,
                Formatting = Formatting.Indented
            });

        return Json(output);
    }

Json()方法还调用序列化.通常，在MVC控制器中，您将只使用Json()方法来序列化您的返回对象，而不是单独使用Json.Net.我可以看到您在这里使用Json.Net来尝试解决序列化数据表时由于循环引用而发生的异常.如果要手动进行序列化，则需要以不会再次进行序列化的方式返回数据.您可以改为使用Content()方法来执行此操作.像这样尝试:

The Json() method also invokes serialization. Normally, in an MVC controller, you would just use the Json() method to serialize your return object, and not use Json.Net separately. I can see you are using Json.Net here to try to get around the exception that happens due to circular references when you try to serialize a data table. If you are going to serialize manually, then you need to return the data in a way that it will not get serialized a second time. You can do this using the Content() method instead. Try it like this:

public ActionResult GetDataTable()
{
    // Build data table
    DataTable dt = new DataTable();
    dt.Columns.Add("DAYDATE", typeof(DateTime));
    dt.Columns.Add("SERIES1", typeof(double));
    dt.Rows.Add(new DateTime(2012, 5, 22, 0, 15, 0), 3.65);

    // Serialize data table using Json.Net to avoid circular reference error
    string output = JsonConvert.SerializeObject(dt,
        new JsonSerializerSettings
        {
            ReferenceLoopHandling = ReferenceLoopHandling.Ignore,
            Formatting = Formatting.Indented
        });

    // Output is already serialized; return it as is (with the appropriate media type)
    return Content(output, "application/json");
}

在我的测试中，以上内容将产生以下输出，我认为这是您想要的:

In my testing, the above will produce the following output, which I think is what you are looking for:

[ { "DAYDATE": "2012-05-22T00:15:00", "SERIES1": 3.65 } ]

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