如何从VB.NET的TXT文件中读取特定的文本行？

Question

So say I wanted to MsgBox line 5 of a txt file, how would I do that? I've Googled for ages, but I can't seem to find anything of use to me.

Answer 1

You can use System.IO.File.ReadLines and Enumerable.ElementAtOrDefault :

Dim line5 = File.ReadLines(pathToFile).ElementAtOrDefault(4)
If line5 IsNot Nothing Then
    MessageBox.Show(line5)
End If

You need to add Imports System.Linq for the LINQ extension methods.

Answer 2

You can use the StreamReader class and only have to look the line(s) you want

Dim fileReader As System.IO.StreamReader
fileReader =My.Computer.FileSystem.OpenTextFileReader("C:\\testfile.txt")
Dim stringReader As String
Dim linenum as Integer=0
While not fileReader.EndOfStream()
    stringReader = fileReader.ReadLine()
    linenum = linenum + 1
    If linenum = 5 Then
        MsgBox(stringReader)
        Exit While  'If you are done here
    End If
End While

Hope it helps