数组深度复制 [英] Deep Copy with Array

问题描述

为什么 ICloneable 的 Clone 方法不返回深拷贝?

Why doesn't ICloneable's Clone method return a deep copy?

这是一些示例代码:

class A : ICloneable 
{
    public int x = 2;
    public A(int x)
    {
       this.x = x; 
    }
       
    public A copy()
    {
        A a = new A(this.x);
        return a; 
    }

     public object Clone()
     {
         A a = new A(this.x);
         return a;
     }
}

在Main方法中:

A[] Array1 = new A[4] ;
Array1[0] = new A(0);
Array1[1] = new A(1);
Array1[2] = new A(2);
Array1[3] = new A(3);
A[] Array2 = new A[10];
Array. Copy(Array1, Array2, 4); 

Array2[2].x = 11; 
for (int i = 0; i < 4; i++)
    Console.WriteLine($"Index {i} value: {Array1[i].x}");

记住我只改变了 Array2 中的元素索引 2，这是上面代码的输出，列出了 Array1 中的值:

Remembering that I've only changed element index 2 in Array2, here is the output from the code above, listing the values in Array1:

Index 0 value: 0
Index 1 value: 1
Index 2 value: 11
Index 3 value: 3

Array1 中的索引 2 具有 11 即使我在 Array2 中更改了它并且 class A 实现了 ICloneable！

Index 2 in Array1 has 11 even though I changed it in Array2 and class A implements ICloneable!

Array 实现 ICloneable 有什么好处?

What then is the benefit of Array implementing ICloneable?

推荐答案

来自 http://msdn.microsoft.com/en-us/library/k4yx47a1.aspx:

"如果sourceArray 和destinationArray 都是引用类型的数组或者都是Object 类型的数组，则执行浅拷贝.Array 的浅拷贝是一个新的Array，其中包含对与原始Array 相同元素的引用.元素本身或元素引用的任何内容都不会被复制"

"If sourceArray and destinationArray are both reference-type arrays or are both arrays of type Object, a shallow copy is performed. A shallow copy of an Array is a new Array containing references to the same elements as the original Array. The elements themselves or anything referenced by the elements are not copied"

可能有比这更好的方法，但您可以使用的一种技术是:

There may be a better method than this, but one technique you could use is:

  A[] array2 = array1.Select (a =>(A)a.Clone()).ToArray();

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