反序列化用引号括起来的 JSON 字符串

Question

Is there a way to correctly deserialize a JSON string that begins and ends with double quotes?

This is the contents of the stream being read from a file:

"[{\"startTime\":1610396717400,\"eventCode\":44,\"eventParam\":5},{\"startTime\":1610396717700,\"eventCode\":81,\"eventParam\":56},{\"startTime\":1610396717800,\"eventCode\":44,\"eventParam\":4}"

The JsonSerializer does not seem to deserialize this properly. However, for a JSON file with the following contents, it works as expected:

[{"startTime":1610396717400,"eventCode":44,"eventParam":5},{"startTime":1610396717700,"eventCode":81,"eventParam":56}]

This is the snippet:

public class ControllerEventJson
{
    [JsonProperty("startTime")]
    public long StartTime { get; set; }

    [JsonProperty("eventCode")]
    public int EventCode { get; set; }

    [JsonProperty("eventParam")]
    public int EventParam { get; set; }
}


class Program
{
    static void Main(string[] args)
    {
        using (Stream stream = File.Open("test.json", FileMode.Open))
        using (StreamReader sr = new StreamReader(stream))
        using (JsonTextReader reader = new JsonTextReader(sr))
        {
            // Required for large JSON objects to avoid errors when streaming
            reader.SupportMultipleContent = true;

            JsonSerializer serializer = new JsonSerializer();
            while (reader.Read())
            {
                // Deserialize each object in array individually
                if (reader.TokenType == JsonToken.StartObject)
                {
                    var obj = serializer.Deserialize<ControllerEventJson>(reader);
                    // Do something with obj
                }
            }
        }
    }
}

Answer 1

Well, I mean, if you just want to take out the quotation marks at the start and end, then you can check for it and just remove them artificially and explicitly before reading it with the StreamReader. Something like this:

        string fileName = @"c:\temp\test.json";
        string data = File.ReadAllText(fileName);
        string newFileName = "";
        //If quotation marks are at the start or end, then remove them
        if (data.StartsWith(@"""") || data.EndsWith(@""""))
        {
            newFileName = Path.GetTempFileName();
            using (StreamWriter sw = new StreamWriter(newFileName))
            {
                sw.Write(data.Trim('"'));
            };
        }

        using (Stream stream = File.Open(newFileName != "" ? newFileName : fileName, FileMode.Open))
        using (StreamReader sr = new StreamReader(stream))
        using (JsonTextReader reader = new JsonTextReader(sr))
        {
            // Required for large JSON objects to avoid errors when streaming
            reader.SupportMultipleContent = true;

            JsonSerializer serializer = new JsonSerializer();
            while (reader.Read())
            {
                // Deserialize each object in array individually
                if (reader.TokenType == JsonToken.StartObject)
                {
                    //do stuff
                }
            }
        }

        if (newFileName != "") File.Delete(newFileName); //Clean up after yourself