ACC: Do Not Jump into WITH Statement Blocks

• Microsoft Access versions 7.0, 97

SUMMARY

Advanced: Requires expert coding, interoperability, and multiuser skills.

The With statement enables you to perform a series of references to a specified object without having to repeat the name of the object. For example, if you have a number of different properties to change on a single object, it is more convenient to place the property assignment statements inside the With control structure. In this manner, you have to refer to the object only once instead of having to refer to it with each property assignment.

The following example illustrates the use of the With statement to assign values to several properties of the same object:

      With MyLabel
      .Height = 2000
      .Width = 2000
      .Caption = "This is MyLabel"
   End With 

MORE INFORMATION

To see the behavior of the With statement, follow these steps.

CAUTION: Following the steps in this example will modify the sample database Northwind.mdb. You may want to back up the Northwind.mdb file or perform these steps on a copy of the Northwind database.

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.

REFERENCES

For more information about the With/End With statements, search the Help Index for "With Statement," or ask the Microsoft Access 97 Office Assistant.

Additional query words: loop

Keywords : kbprg
Version : WINDOWS:7.0,97
Platform : WINDOWS
Issue type : kbinfo