指向 C# 中不同 class 拥有的变量

Question

在下面的代码中，我希望以 classA 和 Main 结束，因为 Main 的名字是 "GoodBye" 但是，最后，classA 仍然是 Main 的名字是 'Hello'而 Main 知道它的名称已更改为 'GoodBye'。如何让 classA 看到 Main 的名称已更改为 GoodBye？

这在 C# 中是不允许的并且被认为是不安全的，因此您必须将代码包装在 'unsafe' 块中吗？

经过测试，我了解到使用引用允许 classA 修改 Main 的名称，但不允许 classA 看到 Main 的名称何时被更改。

class Program
{
    static void Main(string[] args)
    {
        string MyName = "Hello";

        Console.WriteLine($"Main thinks Main's name is: {MyName}");
        Console.WriteLine($"");

        Console.WriteLine($"Creating ClassA");
        ClassA classA = new ClassA(ref MyName);

        Console.WriteLine($"Main thinks Main's name is: {MyName}");
        classA.WriteOutMainName();

        MyName = "GoodBye";
        Console.WriteLine($"");
        Console.WriteLine($"Main changed it's name to: {MyName}");
        Console.WriteLine($"");

        Console.WriteLine($"Main thinks Main's name is: {MyName}");
        classA.WriteOutMainName();

    }
}

public class ClassA
{
    string MainName;
    public ClassA(ref string mainName)
    {
        MainName = mainName;
        mainName = "Dog";
    }

    public void WriteOutMainName()
    {
        Console.WriteLine($"ClassA thinks Main's name is: {MainName}");
    }
}

上面的输出如下：

Main thinks Main's name is: hello

Creating ClassA
Main thinks Main's name is: hello
ClassA thinks Main's name is: hello

Main changed it's name to: GoodBye

Main thinks Main's name is: GoodBye
ClassA thinks Main's name is: hello
Press any key to continue . . .

Answer 1

测试艾米上述说法后更新：

下面的工作符合需要：

class Program
{
    static void Main(string[] args)
    {
        //string MyName = "Hello";

        NameHolder MyName = new NameHolder();
        MyName.Name = "hello";

        Console.WriteLine($"Main thinks Main's name is: {MyName.Name}");
        Console.WriteLine($"");

        Console.WriteLine($"Creating ClassA");
        ClassA classA = new ClassA(MyName);

        Console.WriteLine($"Main thinks Main's name is: {MyName.Name}");
        classA.WriteOutMainName();

        MyName.Name = "GoodBye";
        Console.WriteLine($"");
        Console.WriteLine($"Main changed it's name to: {MyName.Name}");
        Console.WriteLine($"");

        Console.WriteLine($"Main thinks Main's name is: {MyName.Name}");
        classA.WriteOutMainName();

    }
}

public class ClassA
{
    NameHolder MainName;
    public ClassA(NameHolder mainName)
    {
        MainName = mainName;
    }

    public void WriteOutMainName()
    {
        Console.WriteLine($"ClassA thinks Main's name is: {MainName.Name}");
    }
}

public class NameHolder
{
    private string name = "";
    public string Name
    {
        get
        {
            return name;
        }
        set
        {
            name = value;
        }
    }
}

输出如下：

Main thinks Main's name is: hello

Creating ClassA

Main thinks Main's name is: hello
ClassA thinks Main's name is: hello

Main changed it's name to: GoodBye

Main thinks Main's name is: GoodBye
ClassA thinks Main's name is: GoodBye
Press any key to continue . . .

编辑 3：你可以简化你的 NameHolder class 如果你没有在 get 和 set 块中做任何事情 special/extra:

public class NameHolder
{
    public string Name {get; set;}
}

指向 C# 中不同 class 拥有的变量

Point to a variable owned by a different class in C#

c#

pointers

ref