vb.net - FileSystemWatcher - Reduce Multiple Event Raising (or Reduce Results of Multiple Events) in Visual Basic (VS 2012 V11) -

i'm trying reduce number of events raised 1 when filesystemwatcher changes (or @ least display text in textbox once when event raised, either removing duplicate text or other method).

is there fix in visual basic, or @ least anyway remove duplicated text have being appended status log textbox (when onchange sub called)?

i've done decent amount of research on , looks there no "simple" fix.

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here list of resources:

• http://msdn.microsoft.com/en-us/library/system.io.filesystemwatcher.aspx (the microsfot documentation includes notification filesystemwatcher may raise more 1 event.)

• http://weblogs.asp.net/ashben/archive/2003/10/14/31773.aspx (an article states, "to correct problem [two events being raised], remove explicit event handler (addhandler ...)." there no further explanation "...remove explicit event handler (addhandler ...)." means.)

• why filesystemwatcher fire twice (this question asked states "what "remove explicit event handler" mean?" no 1 answered question. also, answer given has portion of code:

  private sub filesystemwatcher1_changed(byval sender system.object, _  byval e system.io.filesystemeventargs) handles filesystemwatcher1.changed 

  when try blue lines under filesystemwatcher1 , this:

  handles clause requires withevents variable defined in containing type or 1 of base types.

  i tried similar fix, setting enableraisingevents = false in onchanged sub, having program need , setting enableraisingevents = true. seems work, sometimes. believe there race condition happening here. enableraisingevents not set false fast enough , multiple onchanges called leading duplicated results.

• http://spin.atomicobject.com/2010/07/08/consolidate-multiple-filesystemwatcher-events (a rather involved fix , in c# , can understand of it, need see in visual basic.)

• http://www.codeproject.com/articles/58740/filesystemwatcher-pure-chaos-part-1-of-2 (this 2 part article in c#, seems solid fix. although lengthy , don't understand of not in visual basic.)

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additional information:

private sub formbackupfile_load(byval sender system.object, byval e _  system.eventargs) handles mybase.load  dim varfilesystemwatcher new filesystemwatcher() dim directorypath string = path.getdirectoryname(textboxfilelocation.text)         varfilesystemwatcher.synchronizingobject = me         varfilesystemwatcher.path = directorypath         varfilesystemwatcher.notifyfilter = (notifyfilters.lastwrite)  ' event raised twice or more addhandler varfilesystemwatcher.changed, addressof onchanged varfilesystemwatcher.enableraisingevents = true  end sub   private sub onchanged(source object, e filesystemeventargs)         ' stops filesystemwatcher firing twice or more but,         ' works @ random.         varfilesystemwatcher.enableraisingevents = false          ' copies specified file specified location         my.computer.filesystem.copyfile(e.fullpath, textboxcopyto.text & "\" _          & e.name, true)          ' text added textbox twice or more.         textboxstatuslog.appendtext(environment.newline & environment.newline & _          statusupdate)          ' starts filesystemwatcher again         varfilesystemwatcher.enableraisingevents = true  end sub