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c# - C# 名称在当前上下文中不存在

问题描述

下面是我的主要代码下面的代码块是我的书类。我对 c# 还很陌生，以前没有遇到过这个错误。我在第 39 行和第 48 行遇到错误。两者都是printInformation()调用。错误是

当前上下文中不存在名称“printInformation”

我不确定该怎么做，我尝试将 book 类和 main 类中的所有代码放入一个单独的文件中，所有代码都放在一起并且不会出错。

这是否意味着就使用的公共和私人课程而言，我需要做一些事情，还是其他事情。title我有用于值、author、price和的公共获取器和设置器isbn。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;


namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Enter the amount of books you have, followed by the number 1 or number 2 seperated by a space");
            Console.Write("Enter 1 if you would like to sort the books by price in ascending order");
            Console.WriteLine("Enter 2 if you would like to sort the books by title alphabetically.");
            string number = Console.ReadLine();
            string[] numberArray = number.Split(' ');
            List<Book> bookList = new List<Book>();

            // for the number entered input values
            for (int i = 0; i < Convert.ToInt16(numberArray[0]); i++)
            {
                bookList.Add(new Book
                {
                    Title = Console.ReadLine(),
                    Author = Console.ReadLine(),
                    Price = Convert.ToDouble(Console.ReadLine()),
                    ISBN = Console.ReadLine()
                });
            }
            // sorting based on condition given
            if (Convert.ToInt16(numberArray[1]) == 1)
            {
                var sortedList = from book in bookList orderby book.Price select book;

                foreach (var book in sortedList)
                {
                    printInformation(book.Title, book.Author, book.Price, book.ISBN);
                }
            }
            else
            {
                var sortedList = from book in bookList orderby book.Title select book;

                foreach (var book in sortedList)
                {
                    printInformation(book.Title, book.Author, book.Price, book.ISBN);
                }
            }

            // added this to hold the console window
            Console.ReadLine();
        }
    }
}

书类：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp1
{
    public class Book
    {
        // private fields
        private string title;
        private string author;
        private double price;
        private string isbn;

        public static void printInformation(string _title, string _author, double _price, string _isbn)
        {
            Console.WriteLine(_title + " written by " + _author + " is " + _price.ToString() + " dollars, with ISBN " + _isbn);
        }
    }
}

标签： c#

解决方案

printInformation方法在Book类中声明为static，因此您需要指定类型名称来调用它：

Book.printInformation(book.Title, book.Author, book.Price, book.ISBN);

顺便说一句，你不需要这个方法，如果你想要 a 的字符串表示Book，更好的方法是覆盖类ToString中的方法Book。

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