在.NET中,哪个JSON库是您使用效果最好的?

30

我很想知道.NET社区中人们一直在使用哪些JSON库? 我需要从.NET(C#)内部解析/序列化一些JSON对象图形到实际的.NET类型。 我可以自己编写,但如果有一些可靠的库,我想听听您的意见。 我看到了json.org网站上的库列表,但这是一个相当大的列表,社区通常很擅长从竞争者中筛选出真正优秀的人。

你对这个库的经验细节(优点/缺点)将非常有帮助。--提前多谢。

7个回答

22

我之前成功地使用过Json.NET

以下是该网站的示例:

Product product = new Product();
product.Name = "Apple";
product.Expiry = new DateTime(2008, 12, 28);
product.Price = 3.99M;
product.Sizes = new string[] { "Small", "Medium", "Large" };

string json = JsonConvert.SerializeObject(product);
//{
//  "Name": "Apple",
//  "Expiry": new Date(1230422400000),
//  "Price": 3.99,
//  "Sizes": [
//    "Small",
//    "Medium",
//    "Large"
//  ]
//}

Product deserializedProduct = JsonConvert.DeserializeObject<Product>(json);

5
记录一下,万一有人看到这个,"Expiry": new Date(1230422400000) 不是有效的 JSON。为了让内容更通俗易懂,我翻译成:只是为了记录,以防有人遇到这种情况,"Expiry": new Date(1230422400000) 并不是有效的 JSON 格式。 - Richard Marskell - Drackir
@RichardMarskell-Drackir,是的。JSON.NET是一个相当不错的库,但这个部分是一个糟糕的例子。我不确定这是否仍然是默认行为,但正如这篇(旧的)文章所解释的那样,您可以使用IsoDateTimeConverter将其序列化/反序列化为(有效的)ISO日期字符串。 - Matthew Flaschen

19

1
编码方面很好用,但对于解码到固定的类层次结构,它与需要解码的动态内容不兼容,因此我使用了System.Web.Helpers.Json.Decode(string)。 我也用它进行编码。 - Wout
2
对于较小的对象,它们可以很好地工作。一旦你使用较大的对象或频繁使用时,内置库的性能就会不足。通过切换到 JSON.Net,我们将序列化和反序列化的时间减少了50%以上。 - CertifiedCrazy

10

我使用位于System.ServiceModel.Web.dll程序集中的DataContractJsonSerializer编写了自己的JSON序列化器。(这是WCF的组件之一,包含在.NET 3.5作为标准程序集以及.NET 3.5 SP1客户端配置文件中。在.NET 4.0和Silverlight 4中,它已经被移至System.Runtime.Serialization.dll)。

using System.IO;
using System.Runtime.Serialization.Json;

public class JsonObjectSerializer 
{
    public string Serialize<T>(T instance) where T : class
    {
        var serializer = new DataContractJsonSerializer(typeof(T));
        using (var memoryStream = new MemoryStream())
        {
            serializer.WriteObject(memoryStream, instance);

            memoryStream.Flush();
            memoryStream.Position = 0;

            using (var reader = new StreamReader(memoryStream))
            {
                return reader.ReadToEnd();
            }
        }
    }

    public T Deserialize<T>(string serialized) where T : class
    {
        var serializer = new DataContractJsonSerializer(typeof(T));
        using (var memoryStream = new MemoryStream())
        {
            using (var writer = new StreamWriter(memoryStream))
            {
                writer.Write(serialized);
                writer.Flush();

                memoryStream.Position = 0;

                return serializer.ReadObject(memoryStream) as T;
            }
        }
    }
}

1
我将其改造为扩展方法以供个人使用,谢谢 :) - Chad Grant
如何防止DataContractJsonSerializer返回XML而不是JSON? - devlord

4
你也应该尝试我的ServiceStack JsonSerializer - 它是目前最快的.NET JSON序列化器基于领先JSON序列化器的基准测试,支持序列化任何POCO类型、DataContracts、Lists/Dictionaries、接口、继承、晚期绑定对象(包括匿名类型)等。
基本示例:
Customer customer = new Customer { Name="Joe Bloggs", Age=31 };
string json = customer.ToJson();
Customer fromJson = json.FromJson<Customer>(json); 

1
不幸的是,它是在AGPL许可下发布的,这意味着它只能用于开源软件,即使您正在开发网站也是如此。 - BlueRaja - Danny Pflughoeft
1
v3是BSD许可,而最新的v4也可以在商业许可下使用。 - mythz
1
v3 在哪里可以找到?[编辑] 不用了,我找到了:https://github.com/ServiceStack/ServiceStack.Text/releases/tag/v3-snapshot - BlueRaja - Danny Pflughoeft
@mythz 你确定你的库比Jil更快吗?;) 另外,你的基准链接已经失效了... - nawfal

3

请查看包含在.NET 3.5中的System.Runtime.Serialization.Json命名空间。


7
如果您感兴趣的话,它存在于System.ServiceModel.Web中。 - Boris Callens
1
-1 直到我弄清楚这个与 https://dev59.com/JXRB5IYBdhLWcg3wn4YL#571200 的区别,后者是在此之前发布的。 - Ruben Bartelink
1
包括框架版本并保持简洁。 - Dean Radcliffe

2

我在谷歌上搜索了"json",顶部的结果是json.org,在那里可以找到一个看起来很不错的单一实用类:

using System;
using System.Collections;
using System.Globalization;
using System.Text;

namespace Procurios.Public
{
    /// <summary>
    /// This class encodes and decodes JSON strings.
    /// Spec. details, see http://www.json.org/
    /// 
    /// JSON uses Arrays and Objects. These correspond here to the datatypes ArrayList and Hashtable.
    /// All numbers are parsed to doubles.
    /// </summary>
    public class JSON
    {
        public const int TOKEN_NONE = 0; 
        public const int TOKEN_CURLY_OPEN = 1;
        public const int TOKEN_CURLY_CLOSE = 2;
        public const int TOKEN_SQUARED_OPEN = 3;
        public const int TOKEN_SQUARED_CLOSE = 4;
        public const int TOKEN_COLON = 5;
        public const int TOKEN_COMMA = 6;
        public const int TOKEN_STRING = 7;
        public const int TOKEN_NUMBER = 8;
        public const int TOKEN_TRUE = 9;
        public const int TOKEN_FALSE = 10;
        public const int TOKEN_NULL = 11;

        private const int BUILDER_CAPACITY = 2000;

        /// <summary>
        /// Parses the string json into a value
        /// </summary>
        /// <param name="json">A JSON string.</param>
        /// <returns>An ArrayList, a Hashtable, a double, a string, null, true, or false</returns>
        public static object JsonDecode(string json)
        {
            bool success = true;

            return JsonDecode(json, ref success);
        }

        /// <summary>
        /// Parses the string json into a value; and fills 'success' with the successfullness of the parse.
        /// </summary>
        /// <param name="json">A JSON string.</param>
        /// <param name="success">Successful parse?</param>
        /// <returns>An ArrayList, a Hashtable, a double, a string, null, true, or false</returns>
        public static object JsonDecode(string json, ref bool success)
        {
            success = true;
            if (json != null) {
                char[] charArray = json.ToCharArray();
                int index = 0;
                object value = ParseValue(charArray, ref index, ref success);
                return value;
            } else {
                return null;
            }
        }

        /// <summary>
        /// Converts a Hashtable / ArrayList object into a JSON string
        /// </summary>
        /// <param name="json">A Hashtable / ArrayList</param>
        /// <returns>A JSON encoded string, or null if object 'json' is not serializable</returns>
        public static string JsonEncode(object json)
        {
            StringBuilder builder = new StringBuilder(BUILDER_CAPACITY);
            bool success = SerializeValue(json, builder);
            return (success ? builder.ToString() : null);
        }

        protected static Hashtable ParseObject(char[] json, ref int index, ref bool success)
        {
            Hashtable table = new Hashtable();
            int token;

            // {
            NextToken(json, ref index);

            bool done = false;
            while (!done) {
                token = LookAhead(json, index);
                if (token == JSON.TOKEN_NONE) {
                    success = false;
                    return null;
                } else if (token == JSON.TOKEN_COMMA) {
                    NextToken(json, ref index);
                } else if (token == JSON.TOKEN_CURLY_CLOSE) {
                    NextToken(json, ref index);
                    return table;
                } else {

                    // name
                    string name = ParseString(json, ref index, ref success);
                    if (!success) {
                        success = false;
                        return null;
                    }

                    // :
                    token = NextToken(json, ref index);
                    if (token != JSON.TOKEN_COLON) {
                        success = false;
                        return null;
                    }

                    // value
                    object value = ParseValue(json, ref index, ref success);
                    if (!success) {
                        success = false;
                        return null;
                    }

                    table[name] = value;
                }
            }

            return table;
        }

        protected static ArrayList ParseArray(char[] json, ref int index, ref bool success)
        {
            ArrayList array = new ArrayList();

            // [
            NextToken(json, ref index);

            bool done = false;
            while (!done) {
                int token = LookAhead(json, index);
                if (token == JSON.TOKEN_NONE) {
                    success = false;
                    return null;
                } else if (token == JSON.TOKEN_COMMA) {
                    NextToken(json, ref index);
                } else if (token == JSON.TOKEN_SQUARED_CLOSE) {
                    NextToken(json, ref index);
                    break;
                } else {
                    object value = ParseValue(json, ref index, ref success);
                    if (!success) {
                        return null;
                    }

                    array.Add(value);
                }
            }

            return array;
        }

        protected static object ParseValue(char[] json, ref int index, ref bool success)
        {
            switch (LookAhead(json, index)) {
                case JSON.TOKEN_STRING:
                    return ParseString(json, ref index, ref success);
                case JSON.TOKEN_NUMBER:
                    return ParseNumber(json, ref index, ref success);
                case JSON.TOKEN_CURLY_OPEN:
                    return ParseObject(json, ref index, ref success);
                case JSON.TOKEN_SQUARED_OPEN:
                    return ParseArray(json, ref index, ref success);
                case JSON.TOKEN_TRUE:
                    NextToken(json, ref index);
                    return true;
                case JSON.TOKEN_FALSE:
                    NextToken(json, ref index);
                    return false;
                case JSON.TOKEN_NULL:
                    NextToken(json, ref index);
                    return null;
                case JSON.TOKEN_NONE:
                    break;
            }

            success = false;
            return null;
        }

        protected static string ParseString(char[] json, ref int index, ref bool success)
        {
            StringBuilder s = new StringBuilder(BUILDER_CAPACITY);
            char c;

            EatWhitespace(json, ref index);

            // "
            c = json[index++];

            bool complete = false;
            while (!complete) {

                if (index == json.Length) {
                    break;
                }

                c = json[index++];
                if (c == '"') {
                    complete = true;
                    break;
                } else if (c == '\\') {

                    if (index == json.Length) {
                        break;
                    }
                    c = json[index++];
                    if (c == '"') {
                        s.Append('"');
                    } else if (c == '\\') {
                        s.Append('\\');
                    } else if (c == '/') {
                        s.Append('/');
                    } else if (c == 'b') {
                        s.Append('\b');
                    } else if (c == 'f') {
                        s.Append('\f');
                    } else if (c == 'n') {
                        s.Append('\n');
                    } else if (c == 'r') {
                        s.Append('\r');
                    } else if (c == 't') {
                        s.Append('\t');
                    } else if (c == 'u') {
                        int remainingLength = json.Length - index;
                        if (remainingLength >= 4) {
                            // parse the 32 bit hex into an integer codepoint
                            uint codePoint;
                            if (!(success = UInt32.TryParse(new string(json, index, 4), NumberStyles.HexNumber, CultureInfo.InvariantCulture, out codePoint))) {
                                return "";
                            }
                            // convert the integer codepoint to a unicode char and add to string
                            s.Append(Char.ConvertFromUtf32((int)codePoint));
                            // skip 4 chars
                            index += 4;
                        } else {
                            break;
                        }
                    }

                } else {
                    s.Append(c);
                }

            }

            if (!complete) {
                success = false;
                return null;
            }

            return s.ToString();
        }

        protected static double ParseNumber(char[] json, ref int index, ref bool success)
        {
            EatWhitespace(json, ref index);

            int lastIndex = GetLastIndexOfNumber(json, index);
            int charLength = (lastIndex - index) + 1;

            double number;
            success = Double.TryParse(new string(json, index, charLength), NumberStyles.Any, CultureInfo.InvariantCulture, out number);

            index = lastIndex + 1;
            return number;
        }

        protected static int GetLastIndexOfNumber(char[] json, int index)
        {
            int lastIndex;

            for (lastIndex = index; lastIndex < json.Length; lastIndex++) {
                if ("0123456789+-.eE".IndexOf(json[lastIndex]) == -1) {
                    break;
                }
            }
            return lastIndex - 1;
        }

        protected static void EatWhitespace(char[] json, ref int index)
        {
            for (; index < json.Length; index++) {
                if (" \t\n\r".IndexOf(json[index]) == -1) {
                    break;
                }
            }
        }

        protected static int LookAhead(char[] json, int index)
        {
            int saveIndex = index;
            return NextToken(json, ref saveIndex);
        }

        protected static int NextToken(char[] json, ref int index)
        {
            EatWhitespace(json, ref index);

            if (index == json.Length) {
                return JSON.TOKEN_NONE;
            }

            char c = json[index];
            index++;
            switch (c) {
                case '{':
                    return JSON.TOKEN_CURLY_OPEN;
                case '}':
                    return JSON.TOKEN_CURLY_CLOSE;
                case '[':
                    return JSON.TOKEN_SQUARED_OPEN;
                case ']':
                    return JSON.TOKEN_SQUARED_CLOSE;
                case ',':
                    return JSON.TOKEN_COMMA;
                case '"':
                    return JSON.TOKEN_STRING;
                case '0': case '1': case '2': case '3': case '4': 
                case '5': case '6': case '7': case '8': case '9':
                case '-': 
                    return JSON.TOKEN_NUMBER;
                case ':':
                    return JSON.TOKEN_COLON;
            }
            index--;

            int remainingLength = json.Length - index;

            // false
            if (remainingLength >= 5) {
                if (json[index] == 'f' &&
                    json[index + 1] == 'a' &&
                    json[index + 2] == 'l' &&
                    json[index + 3] == 's' &&
                    json[index + 4] == 'e') {
                    index += 5;
                    return JSON.TOKEN_FALSE;
                }
            }

            // true
            if (remainingLength >= 4) {
                if (json[index] == 't' &&
                    json[index + 1] == 'r' &&
                    json[index + 2] == 'u' &&
                    json[index + 3] == 'e') {
                    index += 4;
                    return JSON.TOKEN_TRUE;
                }
            }

            // null
            if (remainingLength >= 4) {
                if (json[index] == 'n' &&
                    json[index + 1] == 'u' &&
                    json[index + 2] == 'l' &&
                    json[index + 3] == 'l') {
                    index += 4;
                    return JSON.TOKEN_NULL;
                }
            }

            return JSON.TOKEN_NONE;
        }

        protected static bool SerializeValue(object value, StringBuilder builder)
        {
            bool success = true;

            if (value is string) {
                success = SerializeString((string)value, builder);
            } else if (value is Hashtable) {
                success = SerializeObject((Hashtable)value, builder);
            } else if (value is ArrayList) {
                success = SerializeArray((ArrayList)value, builder);
            } else if (IsNumeric(value)) {
                success = SerializeNumber(Convert.ToDouble(value), builder);
            } else if ((value is Boolean) && ((Boolean)value == true)) {
                builder.Append("true");
            } else if ((value is Boolean) && ((Boolean)value == false)) {
                builder.Append("false");
            } else if (value == null) {
                builder.Append("null");
            } else {
                success = false;
            }
            return success;
        }

        protected static bool SerializeObject(Hashtable anObject, StringBuilder builder)
        {
            builder.Append("{");

            IDictionaryEnumerator e = anObject.GetEnumerator();
            bool first = true;
            while (e.MoveNext()) {
                string key = e.Key.ToString();
                object value = e.Value;

                if (!first) {
                    builder.Append(", ");
                }

                SerializeString(key, builder);
                builder.Append(":");
                if (!SerializeValue(value, builder)) {
                    return false;
                }

                first = false;
            }

            builder.Append("}");
            return true;
        }

        protected static bool SerializeArray(ArrayList anArray, StringBuilder builder)
        {
            builder.Append("[");

            bool first = true;
            for (int i = 0; i < anArray.Count; i++) {
                object value = anArray[i];

                if (!first) {
                    builder.Append(", ");
                }

                if (!SerializeValue(value, builder)) {
                    return false;
                }

                first = false;
            }

            builder.Append("]");
            return true;
        }

        protected static bool SerializeString(string aString, StringBuilder builder)
        {
            builder.Append("\"");

            char[] charArray = aString.ToCharArray();
            for (int i = 0; i < charArray.Length; i++) {
                char c = charArray[i];
                if (c == '"') {
                    builder.Append("\\\"");
                } else if (c == '\\') {
                    builder.Append("\\\\");
                } else if (c == '\b') {
                    builder.Append("\\b");
                } else if (c == '\f') {
                    builder.Append("\\f");
                } else if (c == '\n') {
                    builder.Append("\\n");
                } else if (c == '\r') {
                    builder.Append("\\r");
                } else if (c == '\t') {
                    builder.Append("\\t");
                } else {
                    int codepoint = Convert.ToInt32(c);
                    if ((codepoint >= 32) && (codepoint <= 126)) {
                        builder.Append(c);
                    } else {
                        builder.Append("\\u" + Convert.ToString(codepoint, 16).PadLeft(4, '0'));
                    }
                }
            }

            builder.Append("\"");
            return true;
        }

        protected static bool SerializeNumber(double number, StringBuilder builder)
        {
            builder.Append(Convert.ToString(number, CultureInfo.InvariantCulture));
            return true;
        }

        /// <summary>
        /// Determines if a given object is numeric in any way
        /// (can be integer, double, null, etc). 
        /// 
        /// Thanks to mtighe for pointing out Double.TryParse to me.
        /// </summary>
        protected static bool IsNumeric(object o)
        {
            double result;

            return (o == null) ? false : Double.TryParse(o.ToString(), out result);
        }
    }
}

1
我使用了System.Web.Helpers.Json进行编码和解码。它解码为动态类型,非常适合JavaScript的动态数据。

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