克隆对象在开发过程中经常会遇到,有些时候需要浅克隆,有些时候需要深克隆,具体它们之间有什么区别,以及实现方式有哪些,在这里总结一下。
实现深克隆有以下几种方法。
手动
代码如下:
//手动复制 var user2 = new User { Id = user1.Id, Name = new UserName { FirstName= user1.Name.FirstName, LastName= user1.Name.LastName } };
反射
代码如下:
1 //反射 2 var user3 = user1.Copy() as User;
扩展方法:
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
1 public static class DeepCopyHelper 2 { 3 public static object Copy(this object obj) 4 { 5 Object targetDeepCopyObj; 6 Type targetType = obj.GetType(); 7 //值类型 8 if (targetType.IsValueType == true) 9 { 10 targetDeepCopyObj = obj; 11 } 12 //引用类型 13 else 14 { 15 targetDeepCopyObj = System.Activator.CreateInstance(targetType); //创建引用对象 16 System.Reflection.MemberInfo[] memberCollection = obj.GetType().GetMembers(); 17 18 foreach (System.Reflection.MemberInfo member in memberCollection) 19 { 20 if (member.MemberType == System.Reflection.MemberTypes.Field) 21 { 22 System.Reflection.FieldInfo field = (System.Reflection.FieldInfo)member; 23 Object fieldValue = field.GetValue(obj); 24 if (fieldValue is ICloneable) 25 { 26 field.SetValue(targetDeepCopyObj, (fieldValue as ICloneable).Clone()); 27 } 28 else 29 { 30 field.SetValue(targetDeepCopyObj, Copy(fieldValue)); 31 } 32 33 } 34 else if (member.MemberType == System.Reflection.MemberTypes.Property) 35 { 36 System.Reflection.PropertyInfo myProperty = (System.Reflection.PropertyInfo)member; 37 MethodInfo info = myProperty.GetSetMethod(false); 38 if (info != null) 39 { 40 object propertyValue = myProperty.GetValue(obj, null); 41 if (propertyValue is ICloneable) 42 { 43 myProperty.SetValue(targetDeepCopyObj, (propertyValue as ICloneable).Clone(), null); 44 } 45 else 46 { 47 myProperty.SetValue(targetDeepCopyObj, Copy(propertyValue), null); 48 } 49 } 50 51 } 52 } 53 } 54 return targetDeepCopyObj; 55 } 56 }
序列化
代码如下:
1 //序列化 2 var user4 = user1.DeepClone();
扩展方法:
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
1 /// <summary> 2 /// 深克隆 3 /// 先序列化再反序列化 4 /// </summary> 5 /// <typeparam name="T"></typeparam> 6 /// <param name="obj"></param> 7 /// <returns></returns> 8 public static T DeepClone<T>(this T obj) where T : class 9 { 10 return obj != null ? obj.ToJson().FromJson<T>() : null; 11 }
其它还有使用表达式。
总结:
- 手动复制性能最好,但是遇到很复杂的类的时候,工作量很大。
- 反射和序列化比起来,序列化更简单。