为什么类实例覆盖另一个实例

Question

我有个问题想问你们。

我有一个如下所示的课程：

public class Node
        {
            public int Kova1;               // Kova 1
            public int Kova2;               // Kova 2
            public int Kova3;               // Kova 3

            public int ActionNo;            // Yapılan İşlem

            public Node(int kova1, int kova2, int kova3, int actionNumber)
            {
                Kova1 = kova1;
                Kova2 = kova2;
                Kova3 = kova3;
                ActionNo = actionNumber;
            }

            public Node(int kova1, int kova2, int kova3)
            {
                Kova1 = kova1;
                Kova2 = kova2;
                Kova3 = kova3;
            }

            public Node()
            {
            }

            public Node AnneNode;
        }

还有这些功能：

public void CocukNodeOlustur(LinkedList<Node> Acik, LinkedList<Node> Kapali, Node temp)
{
    Node cocukState;

    Node temp2 = temp;

    for (int i = 0; i < 12; i++)
    {
        cocukState = YeniStateOlustur(temp, i);

        if ((ActionKontrol(cocukState)) && (GoalBulundu(Acik, Kapali, cocukState)) &&
        ((cocukState.Kova1 != temp2.Kova1) && (cocukState.Kova2 != temp2.Kova2) && (cocukState.Kova3 != temp2.Kova3)))
        {
            cocukState.AnneNode = temp;
            Acik.AddFirst(temp);
        }
    }
}

public Node YeniStateOlustur(Node s, int j)
{
    int tempKova1, tempKova2, tempKova3;

    Node yeniCocuk = new Node();

    yeniCocuk = s;
    yeniCocuk.ActionNo = j;

    // Gelen numaraya göre uygulanan işlemin seçimi yapılıyor.
    switch (j)
    {
        case 0:
            {
                yeniCocuk.Kova1 += (3 - yeniCocuk.Kova1);
                yeniCocuk.Kova2 += 0;
                yeniCocuk.Kova3 += 0;
            }
            break;
        case 1:
            {
                yeniCocuk.Kova1 += 0;
                yeniCocuk.Kova2 += (5 - yeniCocuk.Kova2);
                yeniCocuk.Kova3 += 0;
            }
            break;
    }

    return yeniCocuk;
}

在主函数中

            Node temp = new Node();

            while (!(Acik.Count == 0))
            {
                p.CocukNodeOlustur(Acik, Kapali, temp);
                Kapali.AddLast(temp);
            }

所以当我调试我的程序时，我看到每当代码跳转到 YeniStateOlustur() 函数时，程序中的所有 Node 实例都会受到 YeniStateOlustur更改的影响>()。 函数中的实例似乎覆盖了Node类的所有实例。

我不明白为什么会这样？

我该如何克服这个问题？

我对这篇长文致以最诚挚的问候和歉意。

Answer 1

问题在于所有节点都是同一个实例。您的示例代码仅包含两次“new Node()”，在第二种情况下（在方法 YeniStateOlustur 内），新实例会立即被丢弃。因此，该函数返回传递给它的相同节点：

public Node YeniStateOlustur(Node s, int j)  
{  
    int tempKova1, tempKova2, tempKova3;  

    Node yeniCocuk = new Node();  

    yeniCocuk = s;  

    //...

    return yeniCocuk;    
}    

在CocukNodeOlustur方法中，所有节点变量都指向同一个Node：

public void CocukNodeOlustur(LinkedList<Node> Acik, LinkedList<Node> Kapali, Node temp) 
{ 
    // here, temp == temp
    Node cocukState;
    // now, temp == temp and cocukState is uninitialized.
    Node temp2 = temp; 
    // now, temp == temp, temp2 == temp, and cocukState is uninitialized.

    for (int i = 0; i < 12; i++) 
    { 
        cocukState = YeniStateOlustur(temp, i); 
        // now, temp == temp, temp2 == temp, and cocukState == temp

        if ((ActionKontrol(cocukState)) && (GoalBulundu(Acik, Kapali, cocukState)) && 
        ((cocukState.Kova1 != temp2.Kova1) && (cocukState.Kova2 != temp2.Kova2) && (cocukState.Kova3 != temp2.Kova3))) 
        { 
            cocukState.AnneNode = temp; 
            Acik.AddFirst(temp); 
        } 
    } 
} 

您的代码似乎假定 Node 是一个值类型（结构），但它显然是一个引用类型（类）。如果您不确定其中的区别，您应该退后一步，做一些阅读和实验。

一个快速的解决方法可能是将 Node 的声明更改为一个结构，但我不建议这样做。使用结构进行编程可能非常棘手，如果您对结构和类之间的差异的理解不明确，则尤其如此。