CODEWITHSUNDEEP
vb.net
0000
0000

Reputation: 677

CreateText method produces error "The process cannot access the file because it is being used by another process"

I am working on a button that will delete text in gross.txt. I keep getting this error:

The process cannot access the file 'C:\Users\isaiah\Visual BASIC Programs\VB2012\Chap10\Gross Pay Solution\Gross Pay Project\bin\Debug\gross.txt' because it is being used by another process.

Or more specifically:

A first chance exception of type 'System.IO.IOException' occurred in mscorlib.dll.

It appears the error comes from btnDelete_Click at the bottom.

Option Explicit On
Option Strict On
Option Infer Off

Public Class frmMain

    Private Sub btnExit_Click(sender As Object, e As EventArgs) Handles btnExit.Click
        Me.Close()
    End Sub

    Private Sub txtGrossPay_KeyPress(sender As Object, e As KeyPressEventArgs) Handles txtGrossPay.KeyPress

        ' Allows the text box to accept only numbers, the period, and the Backspace key
        If (e.KeyChar < "0" OrElse e.KeyChar > "9") AndAlso e.KeyChar <> "." AndAlso e.KeyChar <> ControlChars.Back Then
            e.Handled = True
        End If
    End Sub

    Private Sub btnSave_Click(sender As Object, e As EventArgs) Handles btnSave.Click

        Dim outFile As IO.StreamWriter
        outFile = IO.File.AppendText("gross.txt")
        outFile.WriteLine(txtGrossPay.Text)
        outFile.Close()

        txtGrossPay.Text = ""
    End Sub

    Private Sub btnDisplay_Click(sender As Object, e As EventArgs) Handles btnDisplay.Click

        ' Declare new inFile Varable as a streamreader object
        Dim inFile As IO.StreamReader
        Dim dblLine As Double

        ' Opens gross.txt for input
        inFile = IO.File.OpenText("gross.txt")

        ' .Exists() searches /bin folder for gross.txt, returns a boolean value
        If IO.File.Exists("gross.txt") Then
            inFile = IO.File.OpenText("gross.txt")

            'Fill the list with the values
            Do Until inFile.Peek = -1

                Double.TryParse(inFile.ReadLine, dblLine)

                lstContents.Items.Add(dblLine.ToString("C2").PadLeft(6, " "c))
            Loop
        Else
            MessageBox.Show("The file you have requested does not exist", "Gross Pay Project",
                            MessageBoxButtons.OKCancel, MessageBoxIcon.Error)
        End If

        inFile.Close()
    End Sub

    Private Sub btnDelete_Click(sender As Object, e As EventArgs) Handles btnDelete.Click
        Dim outDelete As IO.StreamWriter
        outDelete = IO.File.CreateText("gross.txt")
        outDelete.Close()
    End Sub
End Class

Upvotes: 0

Views: 1341

Answers (3)

Scott Savage
Scott Savage

Reputation: 373

The error means what it says. Somewhere you have the file open. Perhaps in Notepad? Are you looking at the contents of the file perhaps?

Upvotes: 0

thetimmer
thetimmer

Reputation: 188

Ok, I found the issue.
You were opening the file twice in your code with the line

inFile = IO.File.OpenText("gross.txt")

I commented out the first time you did it before your .Exists call. I also added a dispose to your Delete call. CreateText doesn't need to assign to anything so I commented out that code and added the line you needed. I tested and these changes fixed the issue. In fact the first change was the fix, the second one was just to clean things up. 

 Private Sub btnDisplay_Click(sender As Object, e As EventArgs) Handles btnDisplay.Click
    'declare new inFile Varable as a streamreader object
    Dim inFile As IO.StreamReader
    Dim dblLine As Double
    'opens gross.txt for input
    ' inFile = IO.File.OpenText("gross.txt")
    '.Exists() searches /bin folder for gross.txt, returns a boolean value
    If IO.File.Exists("gross.txt") Then
        inFile = IO.File.OpenText("gross.txt")
        'fill the list with the values
        Do Until inFile.Peek = -1
            Double.TryParse(inFile.ReadLine, dblLine)
            lstContents.Items.Add(dblLine.ToString("C2").PadLeft(6, " "c))
        Loop
         inFile.Close()
    Else
        MessageBox.Show("The file you have requested does not exist", "Gross Pay Project",
                        MessageBoxButtons.OKCancel, MessageBoxIcon.Error)
    End If
End Sub

Private Sub btnDelete_Click(sender As Object, e As EventArgs) Handles btnDelete.Click 
    'Dim outDelete As IO.StreamWriter
    'outDelete = IO.File.CreateText("gross.txt")
    'outDelete.Close()
    IO.File.CreateText("gross.txt").Dispose
End Sub

Upvotes: 1

thetimmer
thetimmer

Reputation: 188

I believe you need to call dispose ...

Private Sub btnDelete_Click(sender As Object, e As EventArgs) Handles btnDelete.Click
Dim outDelete As IO.StreamWriter
outDelete = IO.File.CreateText("gross.txt")
outDelete.Close()

outDelete.Dispose()
End Sub

Also in your Do Loop are you meaning to add a line when the 

Double.TryParse(inFile.ReadLine, dblLine)

fails to parse? It seems like you would want to skip it if the parse fails

  Do Until inFile.Peek = -1

       if Double.TryParse(inFile.ReadLine, dblLine)  then
          lstContents.Items.Add(dblLine.ToString("C2").PadLeft(6, " "c))
        end if

  Loop

but up to you.

Upvotes: 1

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