Question

我有JSON的搜索结果，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; }
}

我想获得一本书清单。是的，我可以为这种情况编写自己的自定义反序列化器，但我想使用默认的反序列化器。

是否可以做类似的事情？

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

Answer 1

Json.NET不会在没有任何自定义的情况下执行此操作。您有以下方法：

将您的课程发布到http://json2csharp.com/以创建JSON的文字表示，然后使用Linq将结果转换为Book类列表：

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，以便在读取时将JSON转换为您的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，因为您的问题仅询问反序列化。如果需要，您可以类似地实施WriteJson。

使用Linq to JSON将JSON加载到JObject的结构化层次结构中，然后使用Linq将结果转换为Book＆lt; < / p>

    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）

1 个答案: