File.OpenWrite vs StreamWriter

  • Thread starter Thread starter Harry Strybos
  • Start date Start date
H

Harry Strybos

I am confused about which is the better (or safer ) way to write files in
VB.Net.

Using sw As StreamWriter = New StreamWriter(fName)
For Each row As DataRow In ds.Tables(0).Rows

For i As Integer = 0 To (ds.Tables(0).Columns.Count - 1)

col = row(i).ToString.Replace(","c, " "c) 'make sure no extra
commas

If (i < (ds.Tables(0).Columns.Count - 1)) Then

sw.Write(col & ",")

Else

sw.Write(col)

End If

Next

sw.WriteLine()

Next

sw.Close()

End Using

seems very simple, but I am told this method leaves a file open if an error
occurs. Is the File.OpenWrite a safer method?

Thank you
 
I am confused about which is the better (or safer ) way to write files in
VB.Net.

Using sw As StreamWriter = New StreamWriter(fName)
For Each row As DataRow In ds.Tables(0).Rows

For i As Integer = 0 To (ds.Tables(0).Columns.Count - 1)

col = row(i).ToString.Replace(","c, " "c) 'make sure no extra
commas

If (i < (ds.Tables(0).Columns.Count - 1)) Then

sw.Write(col & ",")

Else

sw.Write(col)

End If

Next

sw.WriteLine()

Next

sw.Close()

End Using

seems very simple, but I am told this method leaves a file open if an error

occurs. Is the File.OpenWrite a safer method?
Click to expand...

You have been miss informed - when the resource is declared with a
using block, it's dispose method is automatically called as soon as
you exit the block - even if that is via an error condition. In fact,
your sw.Close() is redundant - since the stream will be closed
automatically on the End Using. You can think of Using as being
essentially the same as:

Dim s As New StreamWriter ()
Try
' a bunch of stuff
Finally
s.Close()
End Try
 
Just curious but does the "Using" re-throw the exception afterwards? It
wouldn't be very nice to have my using statements hiding exceptions from the
rest of my code.

i.e.

Try

Catch eX as Exception

Throw

Finally

' Dispose

End Try
 
Tom Shelton said:
You have been miss informed - when the resource is declared with a
using block, it's dispose method is automatically called as soon as
you exit the block - even if that is via an error condition. In fact,
your sw.Close() is redundant - since the stream will be closed
automatically on the End Using. You can think of Using as being
essentially the same as:

Dim s As New StreamWriter ()
Try
' a bunch of stuff
Finally
s.Close()
End Try
Click to expand...

Thanks, guys
 
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