c# - 编译时错误-无法通过实例引用访问成员

我是尝试理解类以及类如何工作的新手。我正在构建一个小型控制台程序，当前正在处理名为“ LineItem.cs”的“ class.cs”文件，因为它将处理我试图让控制台应用程序生成的收据上的行项目。


  问题：无法使用实例引用访问成员'A070_Classes_CashRegister.Program.receipt（）'；而是使用类型名称对其进行限定。 （错误行：＃21 /第13列）


当我输入'this.color = price;时，我以为是在第21行上完成的。

码：

using System;
namespace a070___Classes___CashRegister
{
  class LineItem     // Class name is singular
                     // receipt might be better name for this class?
  {
    /// Class Attributes
    private String product;     // constructor attribute
    private String description;
    private String color;
    private double price;
    private Boolean isAvailable;

    // constructor called to make object => LineItem
    public LineItem(String product, String description, String color, int price, Boolean isAvailable)
    {
        this.product = product;
        this.description = description;
        this.color = color;
        this.price = price;
        this.isAvailable = isAvailable;// might want to do an availability check
    }

    //Getters
    public String GetProduct() {return product;}
    public String GetDescription(){return description;}//Send description
    public String GetColor() {return color;}

    //Setter
    public void SetColor(string color)//we might want to see it in other colors if is option
    { this.color = color; } //changes object color
  }
}

主文件将调用该类：

using System;

namespace a070___Classes___CashRegister
{
  class Program
  {
    static void receipt()
    {
    //stuff goes here - we call various instances of the class to generate some receipts
    }

    static void Main(string[] args)
    {
        //Program CashRegister = new Program();
        //CashRegister.receipt();

        //Program CashRegister = new Program();
        //CashRegister.receipt();

        receipt();// Don't need to instantiate Program, console applications framework will find the static function Main
        //unless changed your project properties.
        //Since reciept is member od Program and static too, you can just call it directly, without qualification.
    }
  }
}

最佳答案

Program CashRegister = new Program();
CashRegister.receipt();

应该

Program.receipt();

要不就

receipt();

您无需实例化Program，使用控制台应用程序，框架将找到static function Main(...并通过魔术调用，除非您更改了项目属性。

由于receipt也是Program和static的成员，因此您可以直接调用它而无需资格。



receipt()函数是static，但是您正在尝试从实例调用它。

您没有显示receipt的声明位置或调用位置，因此我无济于事。

也许您有一行代码，在其中某处有一个表达式，

... this.receipt() ...

要么

... yourInstance.receipt() ...

但应该是

... Type.receipt() ...