Efficient way to write to a text file and append?

[solarwind3]

I am familiar with two ways of writing to a text file so the data persists when you access it again. Adding more data (from textbox and label) will be necessary for future transactions. I'd like to learn how to write the code so I don't get an UnauthorizedAccessException class.

I am using this way, resulting in error:

Dim objwriter As New System.IO.StreamWriter("C:\Customer Transactions.txt")
 
        objwriter.Write(txtCustName.Text, lblOrderNo, lblFinalCost)
        objwriter.Close()

And there is this way (with errors again):

  Dim myStream As Stream
        Dim saveFileDialg As New SaveFileDialog()
 
        saveFileDialg.Filter = ("C:\Customer Transactions.txt")
        saveFileDialg.FilterIndex = 2
        saveFileDialg.RestoreDirectory = True
 
        If saveFileDialg.ShowDialog() = DialogResult.OK Then
            myStream = saveFileDialg.OpenFile()
            If (myStream IsNot Nothing) Then
                myStream.WriteLine(txtFullName.Text, lblOrder, lblTotal)
                myStream.Close()
                myStream.Close()
            End If
        End If

I'm sure there is something I am not quite getting. Some guidance would be appreciated.

[Frinavale]

The Windows user that is running your application does not have permissions to create files on C:\. You need administrative privileges to change any files in the C:\ root directory.

Try writing the file into the application's executing path instead. For information about getting the application's path check out this article
[url=http://msdn.microsoft.com/en-us/library/aa457089.aspx]
HOW TO: Determine the Executing Application's Path[/icode].

You could also consider writing into the ProgramData path (for example you could try using C:\ProgramData\YourApplicationName).

-Frinny