如何获得其他类设置的值

Question

我是C#的新手，假设我有4门课：

持票人：

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

SecondClass：

public class SecondClass
{
    public void SecondClassMethod()
    {
        Holder holder = new Holder();
        holder.Name = "John";
        Console.WriteLine(holder.Name + " from SecondClass");
    }
}

AnotherClass：

public class AnotherClass
{
    public void AnotherClassMethod()
    {
        Holder holder = new Holder();
        holder.Name = "Raphael";
        Console.WriteLine(holder.Name + " from AnotherClass");
    }

}

和期末课程：

class Program
{
    static void Main(string[] args)
    {
        Holder x1 = new Holder();
        SecondClass x2 = new SecondClass();
        AnotherClass x3 = new AnotherClass();

        x1.Name = "Nobody";
        Console.WriteLine(x1.Name);
        x2.SecondClassMethod();
        Console.WriteLine(x1.Name);
        x3.AnotherClassMethod();
        Console.WriteLine(x1.Name);

        Console.ReadLine();            
    }
}

运行程序后输出：

Nobody
John from SecondClass
Nobody
Raphael from AnotherClass
Nobody

我的问题是:如何使用Program类获得正确的名称(由其他类指定)？问题是我想用那套，上霍尔德的课。我搞不懂。

我想要：

Nobody
John from SecondClass
John
Raphael from AnotherClass
Raphael

as输出

Answer 1

在每个类中实例化一个新实例 of Holder。为了修改现有实例，需要对其他类进行传递引用。

您可以通过引入构造函数实现这一点，您可以将对Holder实例的引用存储在私有 (最好是只读) 字段中。

public class SecondClass
{
    private readonly Holder _holder;
    public SecondClass(Holder holder)
    {
        _holder = holder;
    }

    public void SecondClassMethod()
    {
        _holder.Name = "John";
        Console.WriteLine(_holder.Name + " from SecondClass");
    }
}

然后使用该类更改代码：

Holder x1 = new Holder();
SecondClass x2 = new SecondClass(x1);

Answer 2

此外，还可以在类中使用公共财产存储要修改的Holder实例的引用：

public class SecondClass
{
    public Holder Holder { get; set; }

    public SecondClass(){}

    public void SecondClassMethod()
    {
        if (Holder!=null)
        {
            Holder.Name = "John";
            Console.WriteLine(Holder.Name + " from SecondClass");
        } 
    }
}

然后在Main方法中可以这样做：

Holder x1 = new Holder();
SecondClass x2 = new SecondClass(){Holder=x1};
x2.SecondClassMethod();