.NET Core 3.0 JsonSerializer.Deserialize to dynamic object

因为官方还不支持返回动态类型的对象，只能自己手写一个，临时测试了下没问题，还有些地方不完善的可以自己拿去修改下。

.net Core3 no support

Add the Json Converter

add using:

• using System.Text.Json;
• using System.Text.Json.Serialization;

 /// <summary> /// Temp Dynamic Converter /// by:tchivs@live.cn /// </summary> public class DynamicJsonConverter : JsonConverter<dynamic> { public override dynamic Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options) { if (reader.TokenType == JsonTokenType.True) { return true; } if (reader.TokenType == JsonTokenType.False) { return false; } if (reader.TokenType == JsonTokenType.Number) { if (reader.TryGetInt64(out long l)) { return l; } return reader.GetDouble(); } if (reader.TokenType == JsonTokenType.String) { if (reader.TryGetDateTime(out DateTime datetime)) { return datetime; } return reader.GetString(); } if (reader.TokenType == JsonTokenType.StartObject) { using JsonDocument documentV = JsonDocument.ParseValue(ref reader); return ReadObject(documentV.RootElement); } // Use JsonElement as fallback. // Newtonsoft uses JArray or JObject. JsonDocument document = JsonDocument.ParseValue(ref reader); return document.RootElement.Clone(); } private object ReadObject(JsonElement jsonElement) { IDictionary<string, object> expandoObject = new ExpandoObject(); foreach (var obj in jsonElement.EnumerateObject()) { var k = obj.Name; var value = ReadValue(obj.Value); expandoObject[k] = value; } return expandoObject; } private object? ReadValue(JsonElement jsonElement) { object? result = null; switch (jsonElement.ValueKind) { case JsonValueKind.Object: result = ReadObject(jsonElement); break; case JsonValueKind.Array: result = ReadList(jsonElement); break; case JsonValueKind.String: //TODO: Missing Datetime&Bytes Convert result = jsonElement.GetString(); break; case JsonValueKind.Number: //TODO: more num type result = 0; if (jsonElement.TryGetInt64(out long l)) { result = l; } break; case JsonValueKind.True: result = true; break; case JsonValueKind.False: result = false; break; case JsonValueKind.Undefined: case JsonValueKind.Null: result = null; break; default: throw new ArgumentOutOfRangeException(); } return result; } private object? ReadList(JsonElement jsonElement) { IList<object?> list = new List<object?>(); foreach (var item in jsonElement.EnumerateArray()) { list.Add(ReadValue(item)); } return list.Count == 0 ? null : list; } public override void Write(Utf8JsonWriter writer, object value, JsonSerializerOptions options) { // writer.WriteStringValue(value.ToString()); } }

How to Use?

var serializerOptions = new JsonSerializerOptions{ Converters = { new DynamicJsonConverter() }};return JsonSerializer.Deserialize<dynamic>("{OK:"200"}", serializerOptions);