重要提示

BinaryFormatter已弃用，2023年11月后将不再在. net中使用。参见BinaryFormatter废弃策略

我已经看到了一些不同的方法，但我使用一个通用的实用方法:

public static T DeepClone<T>(this T obj)
{
 using (var ms = new MemoryStream())
 {
   var formatter = new BinaryFormatter();
   formatter.Serialize(ms, obj);
   ms.Position = 0;

   return (T) formatter.Deserialize(ms);
 }
}

注:

你的类必须被标记为[Serializable]才能工作。 您的源文件必须包括以下代码: 使用System.Runtime.Serialization.Formatters.Binary; 使用先;

    public static object CopyObject(object input)
    {
        if (input != null)
        {
            object result = Activator.CreateInstance(input.GetType());
            foreach (FieldInfo field in input.GetType().GetFields(Consts.AppConsts.FullBindingList))
            {
                if (field.FieldType.GetInterface("IList", false) == null)
                {
                    field.SetValue(result, field.GetValue(input));
                }
                else
                {
                    IList listObject = (IList)field.GetValue(result);
                    if (listObject != null)
                    {
                        foreach (object item in ((IList)field.GetValue(input)))
                        {
                            listObject.Add(CopyObject(item));
                        }
                    }
                }
            }
            return result;
        }
        else
        {
            return null;
        }
    }

这种方式比BinarySerialization快几倍，而且不需要[Serializable]属性。

我写了一个深度对象复制扩展方法，基于递归的“MemberwiseClone”。它的速度很快(比BinaryFormatter快三倍)，并且它适用于任何对象。您不需要默认构造函数或可序列化属性。

源代码:

using System.Collections.Generic;
using System.Reflection;
using System.ArrayExtensions;

namespace System
{
    public static class ObjectExtensions
    {
        private static readonly MethodInfo CloneMethod = typeof(Object).GetMethod("MemberwiseClone", BindingFlags.NonPublic | BindingFlags.Instance);

        public static bool IsPrimitive(this Type type)
        {
            if (type == typeof(String)) return true;
            return (type.IsValueType & type.IsPrimitive);
        }

        public static Object Copy(this Object originalObject)
        {
            return InternalCopy(originalObject, new Dictionary<Object, Object>(new ReferenceEqualityComparer()));
        }
        private static Object InternalCopy(Object originalObject, IDictionary<Object, Object> visited)
        {
            if (originalObject == null) return null;
            var typeToReflect = originalObject.GetType();
            if (IsPrimitive(typeToReflect)) return originalObject;
            if (visited.ContainsKey(originalObject)) return visited[originalObject];
            if (typeof(Delegate).IsAssignableFrom(typeToReflect)) return null;
            var cloneObject = CloneMethod.Invoke(originalObject, null);
            if (typeToReflect.IsArray)
            {
                var arrayType = typeToReflect.GetElementType();
                if (IsPrimitive(arrayType) == false)
                {
                    Array clonedArray = (Array)cloneObject;
                    clonedArray.ForEach((array, indices) => array.SetValue(InternalCopy(clonedArray.GetValue(indices), visited), indices));
                }

            }
            visited.Add(originalObject, cloneObject);
            CopyFields(originalObject, visited, cloneObject, typeToReflect);
            RecursiveCopyBaseTypePrivateFields(originalObject, visited, cloneObject, typeToReflect);
            return cloneObject;
        }

        private static void RecursiveCopyBaseTypePrivateFields(object originalObject, IDictionary<object, object> visited, object cloneObject, Type typeToReflect)
        {
            if (typeToReflect.BaseType != null)
            {
                RecursiveCopyBaseTypePrivateFields(originalObject, visited, cloneObject, typeToReflect.BaseType);
                CopyFields(originalObject, visited, cloneObject, typeToReflect.BaseType, BindingFlags.Instance | BindingFlags.NonPublic, info => info.IsPrivate);
            }
        }

        private static void CopyFields(object originalObject, IDictionary<object, object> visited, object cloneObject, Type typeToReflect, BindingFlags bindingFlags = BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.FlattenHierarchy, Func<FieldInfo, bool> filter = null)
        {
            foreach (FieldInfo fieldInfo in typeToReflect.GetFields(bindingFlags))
            {
                if (filter != null && filter(fieldInfo) == false) continue;
                if (IsPrimitive(fieldInfo.FieldType)) continue;
                var originalFieldValue = fieldInfo.GetValue(originalObject);
                var clonedFieldValue = InternalCopy(originalFieldValue, visited);
                fieldInfo.SetValue(cloneObject, clonedFieldValue);
            }
        }
        public static T Copy<T>(this T original)
        {
            return (T)Copy((Object)original);
        }
    }

    public class ReferenceEqualityComparer : EqualityComparer<Object>
    {
        public override bool Equals(object x, object y)
        {
            return ReferenceEquals(x, y);
        }
        public override int GetHashCode(object obj)
        {
            if (obj == null) return 0;
            return obj.GetHashCode();
        }
    }

    namespace ArrayExtensions
    {
        public static class ArrayExtensions
        {
            public static void ForEach(this Array array, Action<Array, int[]> action)
            {
                if (array.LongLength == 0) return;
                ArrayTraverse walker = new ArrayTraverse(array);
                do action(array, walker.Position);
                while (walker.Step());
            }
        }

        internal class ArrayTraverse
        {
            public int[] Position;
            private int[] maxLengths;

            public ArrayTraverse(Array array)
            {
                maxLengths = new int[array.Rank];
                for (int i = 0; i < array.Rank; ++i)
                {
                    maxLengths[i] = array.GetLength(i) - 1;
                }
                Position = new int[array.Rank];
            }

            public bool Step()
            {
                for (int i = 0; i < Position.Length; ++i)
                {
                    if (Position[i] < maxLengths[i])
                    {
                        Position[i]++;
                        for (int j = 0; j < i; j++)
                        {
                            Position[j] = 0;
                        }
                        return true;
                    }
                }
                return false;
            }
        }
    }

}

我认为BinaryFormatter方法相对较慢(这让我很惊讶!)。如果某些对象满足ProtoBuf的要求，你可以使用ProtoBuf. net。从ProtoBuf入门页面(http://code.google.com/p/protobuf-net/wiki/GettingStarted):

支持的类型说明:

自定义类:

被标记为数据契约 有一个无参数的构造函数 对于Silverlight:是公共的 许多公共原语等等。 一维数组:T[] List<T> / IList<T> 字典<TKey, TValue> /字典<TKey, TValue> 实现IEnumerable<T>并具有Add(T)方法的任何类型

代码假设类型将围绕所选成员进行更改。因此，不支持自定义结构，因为它们应该是不可变的。

如果你的课程符合这些要求，你可以尝试:

public static void deepCopy<T>(ref T object2Copy, ref T objectCopy)
{
    using (var stream = new MemoryStream())
    {
        Serializer.Serialize(stream, object2Copy);
        stream.Position = 0;
        objectCopy = Serializer.Deserialize<T>(stream);
    }
}

这确实非常快……

编辑:

下面是对其进行修改的代码(在. net 4.6上进行了测试)。它使用System.Xml.Serialization和System.IO。不需要将类标记为可序列化的。

public void DeepCopy<T>(ref T object2Copy, ref T objectCopy)
{
    using (var stream = new MemoryStream())
    {
        var serializer = new XS.XmlSerializer(typeof(T));

        serializer.Serialize(stream, object2Copy);
        stream.Position = 0;
        objectCopy = (T)serializer.Deserialize(stream);
    }
}

最好的方法是:

    public interface IDeepClonable<T> where T : class
    {
        T DeepClone();
    }

    public class MyObj : IDeepClonable<MyObj>
    {
        public MyObj Clone()
        {
            var myObj = new MyObj();
            myObj._field1 = _field1;//value type
            myObj._field2 = _field2;//value type
            myObj._field3 = _field3;//value type

            if (_child != null)
            {
                myObj._child = _child.DeepClone(); //reference type .DeepClone() that does the same
            }

            int len = _array.Length;
            myObj._array = new MyObj[len]; // array / collection
            for (int i = 0; i < len; i++)
            {
                myObj._array[i] = _array[i];
            }

            return myObj;
        }

        private bool _field1;
        public bool Field1
        {
            get { return _field1; }
            set { _field1 = value; }
        }

        private int _field2;
        public int Property2
        {
            get { return _field2; }
            set { _field2 = value; }
        }

        private string _field3;
        public string Property3
        {
            get { return _field3; }
            set { _field3 = value; }
        }

        private MyObj _child;
        private MyObj Child
        {
            get { return _child; }
            set { _child = value; }
        }

        private MyObj[] _array = new MyObj[4];
    }

重要提示

BinaryFormatter已弃用，2023年11月后将不再在. net中使用。参见BinaryFormatter废弃策略

我已经看到了一些不同的方法，但我使用一个通用的实用方法:

public static T DeepClone<T>(this T obj)
{
 using (var ms = new MemoryStream())
 {
   var formatter = new BinaryFormatter();
   formatter.Serialize(ms, obj);
   ms.Position = 0;

   return (T) formatter.Deserialize(ms);
 }
}

注:

你的类必须被标记为[Serializable]才能工作。 您的源文件必须包括以下代码: 使用System.Runtime.Serialization.Formatters.Binary; 使用先;