I need a delay in visual basic program
I am writing a visual basic program that display the file from a directory in a list box
the app has a button which calls routines to
1. delete files in the directory
2.put some files in the directory
3. get the file info from directory and add file names to a list box
here is code for step 3
my sub
My.Computer.FileSystem.CurrentDirectory ="C:\mtmp"
' Create a reference to the current directory.Dim diAsNew DirectoryInfo(Environment.CurrentDirectory)' Create an array representing the files in the current directory.Dim fiAs FileInfo() = di.GetFiles()Dim fiTempAs FileInfoForEach fiTempIn fiListBox1.Items.Add(fiTemp.Name)
Next fiTempend sub
the problem occours in step 3. If i set a break point on the first line the code works fine. if I just let in go the fileinfo object is empty thus the list box is empty. How do I work around this?
Hi,
I would put a timer in like this.>>
Dim myTimer As Timer
myTimer.Start
Dim fi As FileInfo() = di.GetFiles()
Do
ReDim Preserve fi As FileInfo() = di.GetFiles()
Loop until myTimer=5000 '5000 is 5000 milliseconds = 5 seconds
myTimer.Stop
' Release the timer resources.
myTimer.Close
to give the program the chance to populate the array FileInfo()
See also.>>
http://msdn2.microsoft.com/en-us/library/system.timers.timer_methods.aspx
Regards,
S_DS
why dont you use this simple code? :-)
Dim theFiles() as String = System.IO.Directory.GetFiles("Path")
for each currentItem as String in theFiles
Me.theListBox.Items.Add(currentItem)
end if
there is no need to use a fileinfo object - just using extra resources and ineffecient ;-)
 ahmedilyas wrote: |
| why dont you use this simple code? :-) Dim theFiles() as String = System.IO.Directory.GetFiles("Path") for each currentItem as String in theFile Me.theListBox.Items.Add(currentItem) end if there is no need to use a fileinfo object - just using extra resources and ineffecient ;-) |
|
The only reason I could think of to use FileInfo would be to get just the file name, not the path\filename. But I agree simplify it. Here's what I came up with to do that.
For Each Filename As String In My.Computer.FileSystem.GetFiles("C:\datapath")
ListBox1.Items.Add(New FileInfo(Filename).Name)
Next
It's always interesting to see how many different ways you can do things in the .Net Framework and how the results are often just slightly different depending on what you use. For example, System.IO.Directory.GetFiles returns a string array while My.Computer.FileSystem.GetFiles returns a readonly collection object.
you could also do this to just get the filename:
Dim theFiles() as String = System.IO.Directory.GetFiles("Path")
for each currentItem as String in theFiles
Me.theListBox.Items.Add(System.IO.Path.GetFileName(currentItem))
end if
And there is also
My.Computer.FileSystem.GetFileInfo(Filename).Name
I didn't realize that one was there until I started looking at the different ways to do this.
The System.IO methods return strings, which is slightly faster. The My.Computer.FileSystem methods that return objects seem to add about 10% extra overhead to the operations in my quick stopwatch tests. So it's probably best to favor the System.IO method unless you need the objects for some reason.
| ahmedilyas wrote: |
| you could also do this to just get the filename: Dim theFiles() as String = System.IO.Directory.GetFiles("Path") for each currentItem as String in theFile Me.theListBox.Items.Add(System.IO.Path.GetFileName(currentItem)) end if |
|
Have you left an "s" off the end of theFile in the For Each statement?
I'm comparing your code with your line.>>
Dim theFiles() as String = System.IO.Directory.GetFiles("Path")
Regards,
S_DS.
If you're waiting for files to arrive you may want to use the FileSystemWatcher component. When it stops firing events it should be time to read the folder's contents. This might work best where you have the total number of incoming files and where you could fire off the load listbox routine when the count is reached.
You could also use the BackgroundWorker object to sleep the thread where you load the list box for a short moment to wait for the copying to complete.
