从 JSON 字符串到对象

Question

我有以下有效的 json 字符串：

var result = "[{\"total\":" + wpTotal + ",\"totalpages\":" + wpTotalPages + "},{\"tags\":[{\"id\":384},{\"id\":385}]}]";

我正在尝试使用此方法将其反序列化为 T 类型的对象：

public static T FromJSON<T>(string json)
    {
        using (MemoryStream ms = new MemoryStream(Encoding.UTF8.GetBytes(json)))
        {
            var settings = new DataContractJsonSerializerSettings
            {
                UseSimpleDictionaryFormat = true
            };
            var serializer = new DataContractJsonSerializer(typeof(T), settings);
            return (T)serializer.ReadObject(ms);
        }
    }

并像这样使用它：

var obj = JsonHelper.FromJSON<TagsResponse>(result);

我总是得到空结果 (null)，没有任何异常或任何类型的信息。

我的模型是：

[DataContract]
public class TagsResponse
{
    [DataMember(Name = "total")]
    public int Total { get; set; }

    [DataMember(Name = "totalpages")]
    public int TotalPages { get; set; }

    [DataMember(Name = "tags")]
    public List<Tag> Tags { get; set; }
}

问题出在哪里？

Answer 1

您输入的格式有问题，json 字符串中的属性不是您对象的预期级别，这里是一个工作示例：

class Program
{
    static void Main(string[] args)
    {
        var json = "{\"total\":" + 1 + ",\"totalpages\":" + 10 + ",\"tags\":[{\"id\":384},{\"id\":385}]}";
        var result = json.FromJSON<TagsResponse>();
        Console.WriteLine("Hello World!" + result);
    }
}

public static class Helper
{
    public static T FromJSON<T>(this string json)
    {
        var serializer = new DataContractJsonSerializer(typeof(T));
        using (var ms = new MemoryStream(Encoding.UTF8.GetBytes(json)))
        {
            return (T)serializer.ReadObject(ms);
        }
    }
}

[DataContract]
public class TagsResponse
{
    [DataMember(Name = "total")]
    public int Total { get; set; }

    [DataMember(Name = "totalpages")]
    public int TotalPages { get; set; }

    [DataMember(Name = "tags")]
    public List<Tag> Tags { get; set; }
}

[DataContract]
public class Tag
{
    [DataMember(Name = "id")]
    public string Id { get; set; }
}

Answer 2

1) 创建正确的json

var result = "[{\"total\":" + wpTotal + ",\"totalpages\":" + wpTotalPages + ",\"tags\":[{\"id\":384},{\"id\":385}]}]";

2) 将其解析为数组

var obj = JsonHelper.FromJSON<TagsResponse[]>(result);

或者，如果要解析为单项，可以去掉[] from json

var result = "{\"total\":" + wpTotal + ",\"totalpages\":" + wpTotalPages + ",\"tags\":[{\"id\":384},{\"id\":385}]}";
var obj = JsonHelper.FromJSON<TagsResponse>(result);

从 JSON 字符串到对象

From JSON string to object

c#

json

datacontract

datacontractserializer