CODEWITHSUNDEEP
vb.net
Husna5207
Husna5207

Reputation: 459

why my StringReader doesn't read my txt file in vb.net?

This is my code and I want to read my TestFile.txt file and display it in txt2.Text, but this code doesn't read my txt file. anyone could help me to fixed this problem ? Thanks

Dim MyFileName As String = "C:\Users\TestFile.txt"
Dim Line As String = ""
Dim sb As New StringBuilder
Using sr As New StringReader(MyFileName)
Line = sr.ReadLine
  Do                     
      If Line = "*" Then
      Line = sr.ReadLine
         Do                            
           sb.Append(LineRead)           
           Line = sr.ReadLine
         Loop Until Line = "**"      
     End If
      Line = sr.ReadLine           
 Loop Until Line = ""              
End Using
Line = txt2.Text

Upvotes: 0

Views: 2327

Answers (2)

Thorsten Dittmar
Thorsten Dittmar

Reputation: 56697

You do not append Line to the StringBuilder, but LineRead, which is not set in your code.

Your code should read:

Line = sr.ReadLine
Do                            
    sb.Append(Line)           
    Line = sr.ReadLine
Loop Until Line = "**"

In the comments I've been advised to remove the following bit from my answer:

The real problem are programming languages that don't force you to declare variables before you can use them. You gotta love VB.NET...

I'd like to quote the MSDN here:

By default, the Visual Basic .NET or Visual Basic compiler enforces explicit variable declaration, which requires that you declare every variable before you use it. To change this default behavior, see the Change the Default Project Values section.

So, while by default the commenter is right, you can change the behavior, and nothing in the question tells me the OP didn't change it. Still, I'll rephrase my statement to be more precise:

The real problem are programming languages that allow you to turn of the need to declare variables before you can use them. You gotta love VB.NET...

Upvotes: 1

nos
nos

Reputation: 229058

StringReader just lets you read from a string, it doesn't read or open a file.

Use a StreamReader to read from a file.

  Dim filename As String = "C:\Users\TestFile.txt" 
  Dim Line As String = ""
  Dim sb As New StringBuilder
  Using sr As StreamReader = File.OpenText(filename)
    Line = sr.ReadLine
    Do                     
      If Line = "*" Then
         Line = sr.ReadLine
         Do                            
           sb.Append(Line) ' you probably meant Line, not LineRead      
           Line = sr.ReadLine
         Loop Until Line = "**"      
     End If
      Line = sr.ReadLine           
   Loop Until Line = ""
  End Using

Upvotes: 1

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