vb.net Question???

[Karl@CP PISTONS]

Hi All,

I know there are a lot of vb programmers here so I thought i'd ask. I have a program that checks if a file exists. If not it creates it.

 

As long as I do not use the routine which creates the file all is good.

If the file does not exist the routine crashes at the streamwriter routine with the error: File is in use by another process. The snippet is here :

 

If System.IO.File.Exists(strFileName) = False Then

' Create File

Dim file As System.IO.FileStream

file = System.IO.File.Create(strFileName)

 

End If

 

' File exist already

Dim objWriter As New System.IO.StreamWriter(strFileName)

' Write Header

objWriter.WriteLine("Job# " & txtJobNumber.Text)

 

Do I need to close the file after I create it? If so how?

Thanks in advance!!!

Karl

[Mick from CNC Software Inc.]

You need to close the stream when you are finished writing to it:

 

objWriter.Close()

 

Better yet, place the close call in a Finally block of a try catch, just test to make sure it is not null before calling close().

[Karl@CP PISTONS]

Mick,

I have a close statement after writing. The error comes only when the script has to create the file first in the first place. If the file already exists the streamwriter works as advertised. I am not to familar with the try-catch statement, could you give me an example?

Karl

[Mick from CNC Software Inc.]

Assuming you want to delete an existing file you could try something like the code below. Note that I didnt test this but it should work.

 

code:

---

   Dim objWriter As System.IO.StreamWriter = Nothing

 

Try

 

If System.IO.File.Exists(strFileName) Then

' If it exists do we delete it?

System.IO.File.Delete(strFileName)

End If

 

' Create a new file

objWriter = New System.IO.StreamWriter(strFileName)

' Write Header

objWriter.WriteLine("Job# " & txtJobNumber.Text)

 

 

 

Catch ex As Exception

 

 

Finally

 

If Not objWriter Is Nothing Then

objWriter.Close()

End If

 

 

 

End Try

---

[Karl@CP PISTONS]

Thanks Mick

That solution worked great. I was told

( incorrectly I guess) by another that the file had to be created before the stream writer could use it. The try also is a much more readable style. I am going to use this often.

Karl