TwainException Class

using Leadtools; 
using Leadtools.Twain; 
 
 
public void _twainSession_AcquirePage(object sender, TwainAcquirePageEventArgs e) 
{ 
   Application.DoEvents(); 
 
   if (e.Image != null) 
      e.Image.Dispose(); 
 
   e.Cancel = false; 
} 
public void TwainExceptionExample(IntPtr parent) 
{ 
   TwainSession session = null; 
 
   try 
   { 
      // initialize a new TWAIN session 
      session = new TwainSession(); 
      session.Startup(parent, "manufacturer", "productFamily", "version", "application", TwainStartupFlags.None); 
      session.AcquirePage += new EventHandler<TwainAcquirePageEventArgs>(_twainSession_AcquirePage); 
 
      // acquire a page, if paper jam, allow the user to retry 
      bool done = false; 
      while (!done) 
      { 
         try 
         { 
            DialogResult res = session.Acquire(TwainUserInterfaceFlags.Modal | TwainUserInterfaceFlags.Show); 
            MessageBox.Show("Success"); 
            done = true; 
         } 
         catch (TwainException ex) 
         { 
            if (ex.Code == TwainExceptionCode.PaperJam) 
            { 
               if (MessageBox.Show("Paper jam.  Fix and retry?", "TWAIN", MessageBoxButtons.YesNo) == DialogResult.No) 
                  done = true; 
            } 
            else 
            { 
               // other error, propogate 
               throw ex; 
            } 
         } 
      } 
   } 
   catch (TwainException ex) 
   { 
      MessageBox.Show(string.Format("Twain error:{0}Code: {1}{0}Message: {2}", Environment.NewLine, ex.Code, ex.Message)); 
   } 
   catch (Exception ex) 
   { 
      MessageBox.Show(string.Format("Other error: Message:{0}", ex.Message)); 
   } 
   finally 
   { 
      if (session != null) 
         session.Shutdown(); 
   } 
}