将 JSON 搜索结果反序列化为强类型列表 (JSON.NET)

Question

我在 JSON 中有搜索结果，我想将其反序列化为强类型对象

例如：

{
    searchresult: {
        resultscount: 15,
        results: [
            {
                resultnumber: 1,
                values: [
                    {
                        key:    "bookid",
                        value:  1424
                    },
                    {
                        key:    "name",
                        value:  "C# in depth"
                    },
                ]
            }
        ]
    }
}

我有这个 POCO

public class Book {
    public int BookId { get; set; }
    public string Name { get; set; }
}

我想要一份图书清单。是的，我可以为这种情况编写自己的自定义解串器，但我想使用默认的解串器。

是否可以这样做？

IEnumerable<Book> books = JsonConvert.DeserializeObject<IEnumerable<Book>>(json);

Answer 1

如果没有任何定制，

Json.NET 不会这样做。您有以下方法：

Post 你的类到 http://json2csharp.com/ 创建你的 JSON 的文字表示，然后使用 Linq 将结果转换成列表Book 类:

public class Value
{
    public string key { get; set; }
    public string value { get; set; } // Type changed from "object" to "string".
}

public class Result
{
    public int resultnumber { get; set; }
    public List<Value> values { get; set; }
}

public class Searchresult
{
    public int resultscount { get; set; }
    public List<Result> results { get; set; }
}

public class RootObject
{
    public Searchresult searchresult { get; set; }
}

然后

    var root = JsonConvert.DeserializeObject<RootObject>(json);
    var books = root.searchresult.results.Select(result => new Book { Name = result.values.Find(v => v.key == "name").value, BookId = result.values.Find(v => v.key == "bookid").value });

创建自定义 JsonConverter 以将 JSON 转换为正在读取的 POCO，例如：

internal class BookConverter : JsonConverter
{
    public override bool CanWrite
    {
        get
        {
            return false;
        }
    }

    public override bool CanConvert(Type objectType)
    {
        return objectType == typeof(Book);
    }

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        var values = serializer.Deserialize<List<KeyValuePair<string, string>>>(reader);
        if (values == null)
            return existingValue;
        var book = existingValue as Book;
        if (book == null)
            book = new Book();
        // The following throws an exception on missing keys.  You could handle this differently if you prefer.
        book.BookId = values.Find(v => v.Key == "bookid").Value;
        book.Name = values.Find(v => v.Key == "name").Value;
        return book;
    }

    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        throw new NotImplementedException();
    }
}

public class Result
{
    public int resultnumber { get; set; }

    [JsonProperty("values")] 
    [JsonConverter(typeof(BookConverter))]
    public Book Book { get; set; }
}

public class Searchresult
{
    public int resultscount { get; set; }
    public List<Result> results { get; set; }
}

public class RootObject
{
    public Searchresult searchresult { get; set; }
}

然后

    var root = JsonConvert.DeserializeObject<RootObject>(json);
    var books = root.searchresult.results.Select(result => result.Book);

这里我只实现了 ReadJson 因为你的问题只问反序列化。如果需要，您可以类似地实施 WriteJson。

使用 Linq to JSON to load the JSON into a structured hierarchy of JObject，然后使用 Linq 将结果转换为 Book：

    var books = 
        JObject.Parse(json).Descendants()
            .OfType<JProperty>()
            .Where(p => p.Name == "values")
            .Select(p => p.Value.ToObject<List<KeyValuePair<string, string>>>())
            .Select(values => new Book { Name = values.Find(v => v.Key == "name").Value, BookId = values.Find(v => v.Key == "bookid").Value })
            .ToList();

将 JSON 搜索结果反序列化为强类型列表 (JSON.NET)

Deserializing JSON search results into strongly typed lists (JSON.NET)

c#

json

json.net

deserialization