run time error for reading the text file

[asm]

Hi

I am running the below mention code in vb.net but problem is
when dir.txt already in c: drive it will read the text file
but if i delete the dir.txt file and create new one and in next line
try to read the same dir.txt file it will flash error "Could not find file c:\dir.txt"

Pls guide me .. why this type of problem accured..


thanks


asm

Imports System
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim SFile As System.IO.File
        Dim VolRead As System.IO.StreamReader
        Dim ReadTxt As String
        Try
            If SFile.Exists("C:\DIR.TXT") Then
                System.Diagnostics.Process.Start("C:\Windows\System32\CMD.exe", " /C Del C:\DIR.TXT")
            End If
            System.Diagnostics.Process.Start("C:\Windows\System32\CMD.exe", " /C Dir C:  > C:\DIR.TXT")
            VolRead = New System.IO.StreamReader("C:\DIR.TXT")
            ReadTxt = VolRead.ReadToEnd()
            Label1.Text = "READING TEXT FILE OK.."
            VolRead.Close()
            If SFile.Exists("C:\Dir.txt") Then
                System.Diagnostics.Process.Start("C:\Windows\System32\CMD.exe", " /C Del C:\DIR.TXT")
            End If
        Catch ex As Exception
            Label1.Text = ex.Message
        End Try
    End Sub

[Kimmy4]

Hi, i don't have an answer to your problem but you shouldn't repeat a thread!

Good luck!

[stanav]

The problem is you delete the file, then you try to read it right after that

If SFile.Exists("C:\DIR.TXT") Then
'OK, the file exists... You start cmd.exe and delete the file right here in the line below
                System.Diagnostics.Process.Start("C:\Windows\System32\CMD.exe", " /C [B][Color=Red]Del C:\DIR.TXT"[/Color][/B])
            End If
            'The file got deleted as the result of the above code... Now you try to open it... Why?
            System.Diagnostics.Process.Start("C:\Windows\System32\CMD.exe", " /C Dir C:  > C:\DIR.TXT")

[jmcilhinney]

stanav, that second line isn't trying to read the file. It's performing an operation and redirecting the output to that file.

So, are you saying that this is the line that fails?

VolRead = New System.IO.StreamReader("C:\DIR.TXT")

If so it is because the file hasn't been recreated yet when you try to create the StreamReader. Process.Start doesn't wait for the process to complete, so your process is still running when you try to read the file. You should wait for the process to complete before trying to read the file. Also, you shouldn't be hard-coding the path of cmd.exe because there's no guarantee that Windows is installed on the C drive. The system32 folder is in the environment path variable so you don't need to specify the path at all.

System.Diagnostics.Process.Start("cmd", " /C Dir C:  > C:\DIR.TXT")[U].WaitForExit()[/U]
            VolRead = New System.IO.StreamReader("C:\DIR.TXT")

[stanav]

stanav, that second line isn't trying to read the file. It's performing an operation and redirecting the output to that file.

Ops... my dumd mistake. Thank you for pointing it out.

[gigemboy]

grrrr