file io processing

Hi All,

can anyone tell me where I have gone wrong ?? I am trying to read in a text file and add a ":" to the end of each line, this is what I have so far:

Public Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnProcess.Click
Dim path As String = "c:\mydata\test.txt"

Try
'If File.Exists(path) Then
'File.Delete(path)
'End If

Dim sw As StreamWriter = New StreamWriter(path)
Dim sr As StreamReader = New StreamReader(path)

If sr.Peek() >= -1 Then
sw.WriteLine(":")
End If
sw.Close()
sr.Close()

Catch e As Exception
Console.WriteLine("The process failed: {0}", e.ToString())
End Try

End Sub

Also, if anyone knows how to remove blank lines, this would also be appreciated.

dagoose

dagoose, there are a lot of text file processing threads already on here, just do a search.

But since I'm here...

This is totally off the cuff and untried, but under Try you might want to do something like:

VB Code:

Dim lines() As String
Dim indx As Integer = 0
 
While sr.Peek >= -1
     redim lines(indx) As String
     lines(indx) = sr.ReadLine()
     lines(indx) = lines(indx) & ":"
Next
sr.Close()
 
Dim i As String
For Each i in lines()
     sw.Writeline()
Next
sw.Close()

I don't know for sure if you can have StreamReader and StreamWriter working on the same file at the same time. Either way, you will need a loop to read and write each line of the text file.

This should do what you want:

Code:

---

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim path As String = "c:\test.txt"

        'Count the lines in the file
        Dim LineCounter As New StreamReader(path)
        Dim linecount As Integer = 0
        Do Until LineCounter.Peek = -1
            LineCounter.ReadLine()
            linecount += 1
        Loop
        LineCounter.Close()

        'An array to hold the lines
        Dim Line(0, linecount - 1) As String

        'Read the lines and enter them into the array
        Dim LineReader As New StreamReader(path)
        For FileLine As Integer = 0 To linecount - 1
            Line(0, fileline) = LineReader.ReadLine
        Next FileLine
        LineReader.Close()


        'Pull the line from the array and write them to file
        Dim LineWriter As New StreamWriter(path)
        For FileLine As Integer = 0 To linecount - 1
            LineWriter.WriteLine(Line(0, fileline) & ":")
        Next
        LineWriter.Close()

    End Sub

---

Change the last section to this to remove blank lines in that file:

Code:

---

'Pull the line from the array and write them to file
        Dim LineWriter As New StreamWriter(path)
        For FileLine As Integer = 0 To linecount - 1
            If Not Line(0, fileline) = "" Then
                LineWriter.WriteLine(Line(0, fileline) & ":")
            End If
        Next
        LineWriter.Close()

---

many thanks for your help,

dagoose