ACC: Do Not Jump into WITH Statement Blocks

MORE INFORMATION

1. Open the sample database Northwind.mdb.
2. Create a module and type the following line in the Declarations section:

   Option Explicit

3. Type the following procedure:

          Sub TestWith(MyControl As Control, Optional Action As Variant)
             On Local Error GoTo Tester_Err
                Dim MyAction As Integer
             Const JumpIn = 1
             Const JumpOut = 2
             Const JumpIntoIf = 3
             Const JumpIntoSelect = 4
             MyAction = CInt(Action)
   
             If MyAction = JumpIn Then ' Jump to the WITH block.
                GoTo Tester_Jump1
             ElseIf MyAction = JumpIntoIf Then ' Jump to the IF block.
                GoTo Tester_Jump2
             ElseIf MyAction = JumpIntoSelect Then ' Jump to SELECT block.
                GoTo Tester_Jump3
             End If
   
             ' Start With block.
             With MyControl
                .Caption = "Now Testing"
          Tester_Jump1:
                If MyAction = JumpOut Then ' Jump out of a WITH block
                   GoTo Tester_End
                End If
                .ForeColor = 255
             End With
   
             ' If block test.
             If MyAction Then
          Tester_Jump2:
             End If
   
             ' Select case block test.
             Select Case MyAction
                Case JumpIntoSelect
          Tester_Jump3:
             End Select
          Tester_End:
             Exit Sub
          Tester_Err:
             MsgBox Error$
             Resume Tester_End
          End Sub
   						

4. Save the module and close the Module window.
5. Create the following form with a command button, and then save it as Test1:

          Form: Test1
          -----------------------------
          Caption: TestForm
          ControlSource: <unbound>
   
          Command Button:
             Name: btnTest
             Caption: My Test
             OnClick: [Event Procedure]
   						

6. Set the OnClick property of btnTest command button to the following event procedure:

          Private Sub btnTest_Click()
             Const JumpIn = 1
             Const JumpOut = 2
             Const JumpIntoIf = 3
             Const JumpIntoSelect = 4
   
             Call TestWith(ActiveControl)
             MsgBox "Normal Use of [WITH-END WITH] block"
             Call TestWith(ActiveControl, JumpIn)
             MsgBox "Jumped into [WITH-END WITH] block"
             Call TestWith(ActiveControl, JumpOut)
             MsgBox "Jumped out of [WITH-END WITH] block"
             Call TestWith(ActiveControl, JumpIntoIf)
             MsgBox "Jumped into a [IF-END IF] block"
             Call TestWith(ActiveControl, JumpIntoSelect)
             MsgBox "Jumped into a [SELECT-END SELECT] block"
          End Sub
   						

7. Save the form and view the form in Form view.
8. Click the btnTest command button. Note that the following message appears:
   Normal Use of [WITH-END WITH] block
   This is the normal usage of the With statement. The Caption of the command button changes to "Now Testing," and the button's ForeColor property changes to red (255).
9. Click OK in the message box to continue the program. Note that the following error message appears:
   Object variable or With block variable not set
   This error indicates that the With statement does not support a GoTo entrance into the statement. The next message is:
   Jumped into [WITH-END WITH] block
10. Click OK in the message box to continue the program. The next message is:
    Jumped out of [WITH-END WITH] block
    This message indicates that you can use the GoTo statement to exit a With block.
11. Click the btnTest command button again. The next message is:
    Jumped into a [IF-END IF] block
    This message indicates that the If/End If block statement supports the use of the GoTo statement to enter the block.
12. Click the btnTest command button again. The next message is:
    Jumped into a [SELECT-END SELECT] block
    This message indicates that the Select/End Select block statement supports the use of the GoTo statement to enter the block.