Question

此方法应打印以下内容：

Creating r1
-> Assigning r2 to r1
-> Changing values of r2
String = This is new info!, Top = 10, Bottom = 50, Left = 10, Right = 50
String = This is new info!, Top = 10, Bottom = 4444, Left = 10, Right = 50

但不是打印字符串值，而是打印字符串所在的类

Creating r1
-> Assigning r2 to r1
-> Changing values of r2
String = Csharp_Projects.Program+ShapeInfo, Top = 10, Bottom = 50, Left =  10, Right = 50
String = Csharp_Projects.Program+ShapeInfo, Top = 10, Bottom = 4444, Left = 10, Right = 50

这是代码：

 using System;

 namespace Csharp_Projects
{
  static class Program
{
    static void Main(string[] args)
    {
        ShapeInfo.Rectangle.ValueTypeContainingRefType();
   }

   // this class which takes an string as parameter

    public class ShapeInfo
    {
        public string infoString;

        public ShapeInfo(string info)
        {
            infoString = info;
        }

      // this struct has two fields, one is int type  and the other is ShapeInfo (above) and a constructor which set the values

        public struct Rectangle
        {
            public ShapeInfo rectInfo;

            public int recTop, rectleft, rectBottom, rectRight;

            public Rectangle(string info, int top, int left, int Buttom, int Right)
            {
                rectInfo = new ShapeInfo(info);
                recTop = top;
                rectBottom = Buttom;
                rectRight = Right;
                rectleft = left;
            }
            // this method print the results
            public void Display()
            {
                Console.WriteLine("string={0},top={1},Bottom={2},"+"left={3},Right={4}",rectInfo,recTop,rectBottom,rectRight,rectleft);
            }

            // this method make an object and assign it to second variable and then change the values of second variable .

            public static void ValueTypeContainingRefType()
            {
                Console.WriteLine("Creating r1");
                Rectangle r1 = new Rectangle("First Rec", 10, 10, 50, 50);
                Console.WriteLine("Assigning r2 to r1");
                Rectangle r2 = r1;
                Console.WriteLine("Change Values of r2");
                r2.rectInfo.infoString = "This is new info!";
                r2.rectBottom = 4444;
                r1.Display();
                r2.Display();
            }


        }
    }
}
  }

我真的无法弄清楚为什么会发生这种情况或许我对C＃系统的了解还不够，是什么原因造成的？

Answer 1

您不会覆盖.ToString()类中的ShapeInfo，因此系统无法知道您希望如何将该类的实例打印为字符串。默认情况下，所有对象都会打印它们的类名（因为这几乎是每个类都保证的唯一对象）。

只需override the method：

public override string ToString()
{
    return infoString;
}

Answer 2

您需要覆盖ShapeInfo中的ToString方法以返回infoString。

/es/investigacion/lace/(programa-maestrias|alumni|investigacion|programa-maestrias|alumni/latin-american-forum-entrepreneurs|alumni/fondo-angel-investment|fondo-inversion|investigacion|acerca-del-centro|alumni/estudiantes-del-pais|alumni/mentoring|alumni/incae-entrepreneur-award)\.html|

或者更改要使用的DisplayMethod rectInfo.infoString而不是rectInfo

public override string ToString()
{
    return infoString;
}

打印命名空间而不是字符串值

2 个答案: