有没有更好的方法在 C# 中创建深克隆和浅克隆？

我一直在为一个项目创建对象，在某些情况下我必须为此对象创建深层副本，我想出了使用 C# 的内置函数 MemberwiseClone()。困扰我的问题是，每当我创建一个新类时，我就必须编写一个像下面的代码这样的函数来进行浅拷贝。有人可以帮我改进这部分并给我一个更好的浅拷贝吗比第二行代码。谢谢 ：）

浅拷贝：

public static RoomType CreateTwin(RoomType roomType)
{
    return (roomType.MemberwiseClone() as RoomType);
}

深复制：

public static T CreateDeepClone<T>(T source)
{
    if (!typeof(T).IsSerializable)
    {
        throw new ArgumentException("The type must be serializable.", "source");
    }

    if (Object.ReferenceEquals(source, null))
    {
        return default(T);
    }

    IFormatter formatter = new BinaryFormatter();
    Stream stream = new MemoryStream();
    using (stream)
    {
        formatter.Serialize(stream, source);
        stream.Seek(0, SeekOrigin.Begin);
        return (T)formatter.Deserialize(stream);
    }
}

MemberwiseClone 不是进行深度复制的好选择（MSDN http://msdn.microsoft.com/en-us/library/system.object.memberwiseclone.aspx):

MemberwiseClone 方法通过创建新的对象来创建浅拷贝 对象，然后将当前对象的非静态字段复制到 新对象。如果字段是值类型，则该字段的逐位副本 场进行。如果字段是引用类型，则引用为 已复制但引用的对象未复制;因此，原来的 对象及其克隆引用同一个对象。

这意味着如果克隆对象具有引用类型公共字段或属性，它们将引用与原始对象的字段/属性相同的内存位置，因此克隆对象中的每个更改都将反映在初始对象中。这不是真正的深复制。

您可以使用 BinarySerialization 创建完全独立的对象实例，请参见 MSDN 页面BinaryFormatter 类 http://msdn.microsoft.com/en-us/library/system.runtime.serialization.formatters.binary.binaryformatter.aspx一个序列化的例子。

示例和测试工具：

创建给定对象的深层副本的扩展方法：

public static class MemoryUtils
{
    /// <summary>
    /// Creates a deep copy of a given object instance
    /// </summary>
    /// <typeparam name="TObject">Type of a given object</typeparam>
    /// <param name="instance">Object to be cloned</param>
    /// <param name="throwInCaseOfError">
    /// A value which indicating whether exception should be thrown in case of
    /// error whils clonin</param>
    /// <returns>Returns a deep copy of a given object</returns>
    /// <remarks>Uses BInarySerialization to create a true deep copy</remarks>
    public static TObject DeepCopy<TObject>(this TObject instance, bool throwInCaseOfError)
        where TObject : class
    {
        if (instance == null)
        {
            throw new ArgumentNullException("instance");
        }

        TObject clonedInstance = default(TObject);

        try
        {
            using (var stream = new MemoryStream())
            {
                BinaryFormatter binaryFormatter = new BinaryFormatter();
                binaryFormatter.Serialize(stream, instance);

                // reset position to the beginning of the stream so
                // deserialize would be able to deserialize an object instance
                stream.Position = 0;

                clonedInstance = (TObject)binaryFormatter.Deserialize(stream);
            }
        }
        catch (Exception exception)
        {
            string errorMessage = String.Format(CultureInfo.CurrentCulture,
                            "Exception Type: {0}, Message: {1}{2}",
                            exception.GetType(),
                            exception.Message,
                            exception.InnerException == null ? String.Empty :
                            String.Format(CultureInfo.CurrentCulture,
                                        " InnerException Type: {0}, Message: {1}",
                                        exception.InnerException.GetType(),
                                        exception.InnerException.Message));
            Debug.WriteLine(errorMessage);

            if (throwInCaseOfError)
            {
                throw;
            }
        }

        return clonedInstance;
    }
}

NUnit 测试：

public class MemoryUtilsFixture
{
    [Test]
    public void DeepCopyThrowWhenCopyInstanceOfNonSerializableType()
    {
        var nonSerializableInstance = new CustomNonSerializableType();
        Assert.Throws<SerializationException>(() => nonSerializableInstance.DeepCopy(true));
    }

    [Test]
    public void DeepCopyThrowWhenPassedInNull()
    {
        object instance = null;
        Assert.Throws<ArgumentNullException>(() => instance.DeepCopy(true));
    }

    [Test]
    public void DeepCopyThrowWhenCopyInstanceOfNonSerializableTypeAndErrorsDisabled()
    {
        var nonSerializableInstance = new CustomNonSerializableType();            
        object result = null;

        Assert.DoesNotThrow(() => result = nonSerializableInstance.DeepCopy(false));
        Assert.IsNull(result);
    }

    [Test]
    public void DeepCopyShouldCreateExactAndIndependentCopyOfAnObject()
    {
        var instance = new CustomSerializableType
                        {
                            DateTimeValueType =
                                DateTime.Now.AddDays(1).AddMilliseconds(123).AddTicks(123),
                            NumericValueType = 777,
                            StringValueType = Guid.NewGuid().ToString(),
                            ReferenceType =
                                new CustomSerializableType
                                    {
                                        DateTimeValueType = DateTime.Now,
                                        StringValueType = Guid.NewGuid().ToString()
                                    }
                        };

        var deepCopy = instance.DeepCopy(true);

        Assert.IsNotNull(deepCopy);
        Assert.IsFalse(ReferenceEquals(instance, deepCopy));
        Assert.That(instance.NumericValueType == deepCopy.NumericValueType);
        Assert.That(instance.DateTimeValueType == deepCopy.DateTimeValueType);
        Assert.That(instance.StringValueType == deepCopy.StringValueType);
        Assert.IsNotNull(deepCopy.ReferenceType);
        Assert.IsFalse(ReferenceEquals(instance.ReferenceType, deepCopy.ReferenceType));
        Assert.That(instance.ReferenceType.DateTimeValueType == deepCopy.ReferenceType.DateTimeValueType);
        Assert.That(instance.ReferenceType.StringValueType == deepCopy.ReferenceType.StringValueType);
    }

    [Serializable]
    internal sealed class CustomSerializableType
    {            
        public int NumericValueType { get; set; }
        public string StringValueType { get; set; }
        public DateTime DateTimeValueType { get; set; }

        public CustomSerializableType ReferenceType { get; set; }
    }

    public sealed class CustomNonSerializableType
    {            
    }
}