Error Handling

Private mobjCOMException As System.Runtime.InteropServices.COMException 
Private mobjException As Exception 

Form Load

Private Sub frmMain_Load(ByVal sender As System.Object, _ 
                         ByVal e As System.EventArgs) _ 
                         Handles MyBase.Load 
   Try 
      If clsError.ErrorFlag() = True Then Exit Sub 



   Catch objCOMException As System.Runtime.InteropServices.COMException 
      mobjCOMException = objCOMException 
   Catch objException As Exception 
      mobjException = objException 

   Finally 
      If gbDEBUG = True Or _ 
         ((Not mobjCOMException Is Nothing) Or (Not mobjException Is Nothing)) Then 

         Call clsError.Handle("frmMain_Load", msCLASSNAME, _ 
              "load the form successfully.", _ 
              mobjCOMException, mobjException) 
      End If 
   End Try 
End Sub 

Controls

Private Sub Control_Click(ByVal sender As System.Object, _ 
                          ByVal e As System.EventArgs) _ 
                          Handles btnOK.Click 
   Try 
      If gbfrmMainForm_FireEvents = False Then Exit Sub 
      If clsError.ErrorFlag() = True Then Exit Sub 


   Catch objCOMException As System.Runtime.InteropServices.COMException 
      mobjCOMException = objCOMException 
   Catch objException As Exception 
      mobjException = objException 

   Finally 
      If gbDEBUG = True Or _ 
         ((Not mobjCOMException Is Nothing) Or (Not mobjException Is Nothing)) Then 

         Call clsError.Handle("Control_Click", msCLASSNAME, _ 
              "respond to the control successfully.", _ 
              mobjCOMException, mobjException) 
      End If 
   End Try 
End Sub 

OK Button

Private Sub btnOK_Click(ByVal sender As System.Object, _ 
                        ByVal e As System.EventArgs) _ 
                        Handles btnOK.Click 
   Try 
      If clsError.ErrorFlag() = True Then Exit Sub 



   Catch objCOMException As System.Runtime.InteropServices.COMException 
      mobjCOMException = objCOMException 
   Catch objException As Exception 
      mobjException = objException 

   Finally 
      If gbDEBUG = True Or _ 
         ((Not mobjCOMException Is Nothing) Or (Not mobjException Is Nothing)) Then 

         Call clsError.Handle("btnOK_Click", msCLASSNAME, _ 
              "respond to the control successfully.", _ 
              mobjCOMException, mobjException) 
      End If 
   End Try 
End Sub 

Cancel Button

You must always be able to close the form regardless of whether an error has occurred.

Private Sub btnCancel_Click(ByVal sender As System.Object, _ 
                            ByVal e As System.EventArgs) _ 
                            Handles btnCancel.Click 
   Try 
'this is the correct method form forms that have been displayed using Frm.ShowDialog (i.e. modal)
'this implicitly calls the Me.Close method so you do not need both
      Me.DialogResult = Windows.Forms.DialogResult.Cancel 

'this is the correct method form forms that have been displayed using Frm.Show (i.e. modeless)
      Me.Close 

   Catch objCOMException As System.Runtime.InteropServices.COMException 
      mobjCOMException = objCOMException 
   Catch objException As System.Exception 
      mobjException = objException 

   Finally 
      If gbDEBUG = True Or _ 
         ((Not mobjCOMException Is Nothing) Or (Not mobjException Is Nothing)) Then 

         Call clsError.Handle("btnCancel_Click", msCLASSNAME, _ 
              "respond to the control successfully.", _ 
              mobjCOMException, mobjException) 
      End If 
   End Try 
End Sub 

Form Close

This is only needed if you are saving any settings even when the dialog box is closed using the X in the corner, such as saving the position of the form.

Private Sub frmMain_Close() 

   Try 


   Catch objCOMException As System.Runtime.InteropServices.COMException 
      mobjCOMException = objCOMException 
   Catch objException As System.Exception 
      mobjException = objException 

   Finally 
      If gbDEBUG = True Or _ 
         ((Not mobjCOMException Is Nothing) Or (Not mobjException Is Nothing)) Then 

      Call clsError.Handle("frmName_Main", msCLASSNAME, _ 
           "unload the form successfully.", _ 
           mobjCOMException, mobjException) 
      End If 
   End Try 
End Sub