JSON.Net -反序列化对象格式

Question

我使用JSON。Net试图将一些来自SurveyGizmo的调查回复进行反序列化。以下是我正在读取的数据的快照:

{"result_ok":true,
"total_count":"44",
"page":1,
"total_pages":1,
"results_per_page":50,
"data":[
        {"id":"1",
        "contact_id":"",
        "status":"Complete",
        "is_test_data":"0",
        "datesubmitted":"2011-11-13 22:26:53",
        "[question(59)]":"11/12/2011",
        "[question(60)]":"06:15 pm",
        "[question(62)]":"72",
        "[question(63)]":"One",
        "[question(69), option(10196)]":"10",

我已经设置了一个类的日期提交，但我不知道如何设置类来反序列化的问题，因为问题的数量会改变?我还需要捕获选项，如果它存在的话。

我使用这个代码来使用JSON。. NET反序列化函数:

Dim responses As Responses = JsonConvert.DeserializeObject(Of Responses)(fcontents)

类:

Public Class Responses
    Public Property result_OK As Boolean
    Public Property total_count As Integer
    Public Property page As Integer
    Public Property total_pages As Integer
    Public Property results_per_page As Integer
    Public Overridable Property data As List(Of surveyresponse)
End Class
Public Class SurveyResponse
    Public Property id As Integer
    Public Property status As String
    Public Property datesubmitted As Date
End Class

Answer 1

支持完全疯狂映射的技巧是使用JsonConverter并完全替换该对象的解析(我为c#道歉，但我不擅长VB语法):

class Program
{
    static void Main(string[] args)
    {
        var result = JsonConvert.DeserializeObject<Responses>(TestData);
    }
    const string TestData = @"{""result_ok"":true,
""total_count"":""44"",
""page"":1,
""total_pages"":1,
""results_per_page"":50,
""data"":[
    {""id"":""1"",
    ""contact_id"":"""",
    ""status"":""Complete"",
    ""is_test_data"":""0"",
    ""datesubmitted"":""2011-11-13 22:26:53"",
    ""[question(59)]"":""11/12/2011"",
    ""[question(60)]"":""06:15 pm"",
    ""[question(62)]"":""72"",
    ""[question(63)]"":""One"",
    ""[question(69), option(10196)]"":""10"",
}]}";
}
[JsonObject]
class Responses
{
    public bool result_ok { get; set; }
    public string total_count { get; set; }
    public int page { get; set; }
    public int total_pages { get; set; }
    public int results_per_page { get; set; }
    public SurveyResponse[] Data { get; set; }
}
[JsonObject]
// Here is the magic: When you see this type, use this class to read it.
// If you want, you can also define the JsonConverter by adding it to
// a JsonSerializer, and parsing with that.
[JsonConverter(typeof(DataItemConverter))]
class SurveyResponse
{
    public string id { get; set; }
    public string contact_id { get; set; }
    public string status { get; set; }
    public string is_test_data { get; set; }
    public DateTime datesubmitted { get; set; }
    public Dictionary<int, string> questions { get; set; }
}
class DataItemConverter : JsonConverter
{
    public override bool CanConvert(Type objectType)
    {
        return objectType == typeof(SurveyResponse);
    }
    public override bool CanRead
    {
        get { return true; }
    }
    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        var value = (SurveyResponse)existingValue;
        if (value == null)
        {
            value = new SurveyResponse();
            value.questions = new Dictionary<int, string>()
        }
        // Skip opening {
        reader.Read();
        while (reader.TokenType == JsonToken.PropertyName)
        {
            var name = reader.Value.ToString();
            reader.Read();
                // Here is where you do your magic
            if (name.StartsWith("[question("))
            {
                int index = int.Parse(name.Substring(10, name.IndexOf(')') - 10));
                value.questions[index] = serializer.Deserialize<string>(reader);
            }
            else
            {
                var property = typeof(SurveyResponse).GetProperty(name);
                property.SetValue(value, serializer.Deserialize(reader, property.PropertyType), null);
            }
            // Skip the , or } if we are at the end
            reader.Read();
        }
        return value;
    }
    public override bool CanWrite
    {
        get { return false; }
    }
    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        throw new NotImplementedException();
    }
}

现在很明显，你想要做更多的事情来让它真正健壮，但这给了你如何做到这一点的基本知识。如果您只需要更改属性名称(JsonPropertyAttribute或重写DefaultContractResolver.ResolvePropertyName())，还有更轻量级的替代方案，但这给了您完全的控制权。