繁体   English   中英

如何从文本文件读取到列表并从该列表读取C#

[英]How to Read from a Text File into a List And Read from that list C#

我需要从文本文件中读取,然后将每一行放入列表中,然后从该列表中读取。 但是我收到NullReferenceException“对象引用未设置为对象的实例。” 而一会儿大约下降了7行。 我已经尝试了所有我能想到的。 提前致谢。

                StreamReader sre = new StreamReader(FILE_PATH);
                Books books = new Books();
                string line;
                while ((line = sre.ReadToEnd()) != null)
                {
                 //NullReferenceException is Right here
                 //I defined myLibraryBooks outside of this code; But it is in the same scope
                    myLibraryBooks.Add(new Books() { Author = books.Author.ToUpper(), Title = line.ToUpper(), ISBN = line, Publish_Date = line });
                }
                Console.Write("Enter Author's Name:");
                string input_to_find = Console.ReadLine();
                var author = from Authors in myLibraryBooks
                             where Authors.Author == input_to_find
                             select Authors;

                foreach (var book in author)
                {
                    Console.WriteLine(String.Format("      Author            Title            ISBN            Publish Date"));
                    Console.WriteLine(String.Format("       {0}          {1}              {2}                {3}", books.Author, books.Title, books.ISBN, books.Publish_Date));
                }
                sre.Dispose();

您在声明books ,但是看起来并没有设置任何东西(除非您在构造函数中做了一些奇怪的事情)。 基于此,我想说以下几行可能会导致此异常:

      *Guessing Author is null...
books.Author.ToUpper()

利用.NET的调试工具,逐行检查代码以查看问题出在哪里。

暂无
暂无

声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.

 
粤ICP备18138465号  © 2020-2024 STACKOOM.COM