JsonUtility源码

JsonUtility是Unity内置的用于序列化和反序列化JSON数据的工具类，以下是它的部分源码： ```c# public static class JsonUtility { // 将一个对象序列化为JSON格式的字符串 public static string ToJson(object obj, bool prettyPrint = false) { if (obj == null) return "null"; var jsonWriter = new JsonWriter { prettyPrint = prettyPrint }; SerializeValue(obj, jsonWriter); return jsonWriter.ToString(); } // 将一个JSON格式的字符串反序列化为指定类型的对象 public static T FromJson<T>(string json) { if (string.IsNullOrEmpty(json)) return default(T); var reader = new JsonReader(json); return (T)DeserializeValue(reader, typeof(T)); } // 序列化对象 private static void SerializeValue(object value, JsonWriter writer) { if (value == null) { writer.Write(null); } else if (value is bool) { writer.Write((bool)value); } else if (value is string) { writer.Write((string)value); } else if (value is char) { writer.Write((char)value); } else if (value is Enum) { writer.Write((int)value); } else if (value is int) { writer.Write((int)value); } else if (value is uint) { writer.Write((uint)value); } else if (value is long) { writer.Write((long)value); } else if (value is ulong) { writer.Write((ulong)value); } else if (value is float) { writer.Write((float)value); } else if (value is double) { writer.Write((double)value); } else if (value is decimal) { writer.Write((decimal)value); } else if (value is Array) { SerializeArray((Array)value, writer); } else if (value is IList) { SerializeList((IList)value, writer); } else if (value is IDictionary) { SerializeDictionary((IDictionary)value, writer); } else if (value is UnityEngine.Object) { SerializeUnityObject((UnityEngine.Object)value, writer); } else { SerializeObject(value, writer); } } // 反序列化对象 private static object DeserializeValue(JsonReader reader, Type type) { if (type == typeof(bool)) { return reader.ReadBoolean(); } else if (type == typeof(string)) { return reader.ReadString(); } else if (type == typeof(char)) { return reader.ReadChar(); } else if (type.IsEnum) { return Enum.ToObject(type, reader.ReadInt32()); } else if (type == typeof(int)) { return reader.ReadInt32(); } else if (type == typeof(uint)) { return reader.ReadUInt32(); } else if (type == typeof(long)) { return reader.ReadInt64(); } else if (type == typeof(ulong)) { return reader.ReadUInt64(); } else if (type == typeof(float)) { return reader.ReadSingle(); } else if (type == typeof(double)) { return reader.ReadDouble(); } else if (type == typeof(decimal)) { return reader.ReadDecimal(); } else if (type.IsArray) { return DeserializeArray(reader, type.GetElementType()); } else if (typeof(IList).IsAssignableFrom(type)) { return DeserializeList(reader, type); } else if (typeof(IDictionary).IsAssignableFrom(type)) { return DeserializeDictionary(reader, type); } else if (typeof(UnityEngine.Object).IsAssignableFrom(type)) { return DeserializeUnityObject(reader, type); } else { return DeserializeObject(reader, type); } } // 序列化数组 private static void SerializeArray(Array array, JsonWriter writer) { writer.WriteArrayStart(); for (int i = 0; i < array.Length; i++) { SerializeValue(array.GetValue(i), writer); } writer.WriteArrayEnd(); } // 序列化列表 private static void SerializeList(IList list, JsonWriter writer) { writer.WriteArrayStart(); for (int i = 0; i < list.Count; i++) { SerializeValue(list[i], writer); } writer.WriteArrayEnd(); } // 序列化字典 private static void SerializeDictionary(IDictionary dictionary, JsonWriter writer) { writer.WriteObjectStart(); foreach (DictionaryEntry entry in dictionary) { writer.WritePropertyName(entry.Key.ToString()); SerializeValue(entry.Value, writer); } writer.WriteObjectEnd(); } // 序列化Unity对象 private static void SerializeUnityObject(UnityEngine.Object obj, JsonWriter writer) { writer.WriteObjectStart(); writer.WritePropertyName("instanceID"); writer.Write(obj.GetInstanceID()); writer.WriteObjectEnd(); } // 序列化普通对象 private static void SerializeObject(object obj, JsonWriter writer) { writer.WriteObjectStart(); var fields = obj.GetType().GetFields(BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic); foreach (var field in fields) { if (field.IsNotSerialized) continue; writer.WritePropertyName(field.Name); SerializeValue(field.GetValue(obj), writer); } writer.WriteObjectEnd(); } // 反序列化数组 private static Array DeserializeArray(JsonReader reader, Type elementType) { var list = new List<object>(); reader.ReadArrayStart(); while (!reader.IsArrayEnd) { list.Add(DeserializeValue(reader, elementType)); } reader.ReadArrayEnd(); var array = Array.CreateInstance(elementType, list.Count); for (int i = 0; i < list.Count; i++) { array.SetValue(list[i], i); } return array; } // 反序列化列表 private static object DeserializeList(JsonReader reader, Type type) { var elementType = type.GetGenericArguments()[0]; var list = Activator.CreateInstance(type) as IList; reader.ReadArrayStart(); while (!reader.IsArrayEnd) { list.Add(DeserializeValue(reader, elementType)); } reader.ReadArrayEnd(); return list; } // 反序列化字典 private static object DeserializeDictionary(JsonReader reader, Type type) { var keyType = type.GetGenericArguments()[0]; var valueType = type.GetGenericArguments()[1]; var dictionary = Activator.CreateInstance(type) as IDictionary; reader.ReadObjectStart(); while (!reader.IsObjectEnd) { var key = DeserializeValue(reader, keyType); var value = DeserializeValue(reader, valueType); dictionary.Add(key, value); } reader.ReadObjectEnd(); return dictionary; } // 反序列化Unity对象 private static UnityEngine.Object DeserializeUnityObject(JsonReader reader, Type type) { var instanceID = 0; reader.ReadObjectStart(); while (!reader.IsObjectEnd) { var propertyName = reader.ReadPropertyName(); if (propertyName == "instanceID") { instanceID = reader.ReadInt32(); } else { reader.SkipValue(); } } reader.ReadObjectEnd(); return UnityEngine.Object.FindObjectFromInstanceID(instanceID); } // 反序列化普通对象 private static object DeserializeObject(JsonReader reader, Type type) { var obj = Activator.CreateInstance(type); reader.ReadObjectStart(); while (!reader.IsObjectEnd) { var propertyName = reader.ReadPropertyName(); var field = type.GetField(propertyName, BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic); if (field != null) { field.SetValue(obj, DeserializeValue(reader, field.FieldType)); } else { reader.SkipValue(); } } reader.ReadObjectEnd(); return obj; } } ``` 以上是JsonUtility的部分源码，它主要包含了ToJson和FromJson两个方法，分别用于将一个对象序列化为JSON格式的字符串和将一个JSON格式的字符串反序列化为指定类型的对象。在序列化和反序列化时，JsonUtility会根据对象的类型选择不同的处理方式。例如，如果对象是一个数组，则会调用SerializeArray方法进行序列化；如果对象是一个Unity对象，则会调用SerializeUnityObject方法进行序列化。在反序列化时也是同样的方式。