如何搜索特定字符串并返回整行？在VB.NET中 [英] How can I search for a specific string and return whole line? In VB.NET

问题描述

如何从My.Resources.filetxt搜索特定字符串并返回整行？

how can I search for a specific string from My.Resources.filetxt and return whole line?

e.g My.Resources.filetxt has following entries say :

england is cold country
england is cold country
england is cold country

现在我想在这个txt文件中搜索字符串england并返回整行包含这个字符串。我该怎么办



我的尝试：

now i want to search this txt file for a string "england" and return the entire line containing this string. How can i do it

What I have tried:

Findstring = My.Resources.filetxt
       Lookfor = TextBox2.Text
       'TextBox1.Text = IO.File.ReadAllLines(My.Resources.filetxt).FirstOrDefault(Function(x) x.Contains(Lookfor))

推荐答案

两种方法：

1）将文本拆分为单独的行，并在每行中搜索文本。这不是特别有效，特别是如果您的文本很长并且包含许多行，因为它会生成许多单独的字符串。它很容易实现 - 几行代码。

2）使用IndexOf依次查找字符串的每个出现：String.IndexOf Method（String，Int32）（System） [ ^ ]。然后，您可以使用返回的索引再次使用它来查找行的末尾，并且 String.LastIndexOf方法（String，Int32）（系统） [ ^ ]找到开头。然后，您可以使用 String.Substring方法（Int32，Int32）提取整行。 （系统） [ ^ ]。这是一个更多的工作，但会更快，并且整个负载更少的内存猪！

Two ways to do it:
1) Split the text into separate lines, and search each line for your text. This isn't particularly efficient, particularly if your text is long and contains many lines as it generates a lot of separate strings. It is easy to implement though - a couple of lines of code.
2) Use IndexOf to find each occurance of the string in turn: String.IndexOf Method (String, Int32) (System)[^]. You can then use it again with the returned index to find the end of the line, and String.LastIndexOf Method (String, Int32) (System)[^] to find the beginning. You can then extract the whole line using String.Substring Method (Int32, Int32) (System)[^]. This is a little more work, but will be a lot quicker, and a whole load less of a memory hog!

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