ACC2000: Macro on Subform Control Executed by Main Form

• Microsoft Access 2000

SYMPTOMS

Moderate: Requires basic macro, coding, and interoperability skills.

If a macro is attached to the OnEnter or OnExit property of the first control in the tab order of a subform, the macro will run each time that you move from one record to another in the main form.

In addition, a macro attached to the OnEnter property of the first control in the tab order of the subform will run when the main form is opened, and a macro attached to the OnExit property of the first control in the tab order of the subform will run when the main form is closed.

CAUSE

The macro attached to the OnEnter property of the first control in the subform will not run if you enter the control from the main form and the control is in the selected record on the subform (denoted by a triangle in the record selector). As a result, the macro will not run when you enter the subform by pressing TAB, or by clicking the first control in the selected record on the subform. However, the macro will run if you click this control on a different record in the subform.

RESOLUTION

To cause a macro to run only when you are actually moving in and out of the subform, use a test condition with a flag. A macro can set a flag on the main form to indicate whether the subform was entered by moving into the subform from the main form. The macro attached to the subform's OnEnter and OnExit properties can check this flag to see if you really did move into the subform and continue running if appropriate. The following steps demonstrate how to set up and test for this condition.

1. Create the following macro called Subform Flag:




   Macro Name     Action
   -----------------------
   Set            SetValue
   UnSet          SetValue

   Subform Flag Actions
   -----------------------
   SetValue
      Item: [Subform Flag]
      Expression: True
   SetValue
      Item: [Subform Flag]
      Expression: False 

2. For a form named MyForm, add an unbound text box to the main form with the following properties:




   Form: MyForm
   Text Box: Subform Flag
   Name: Subform Flag 
   Visible: No
   Default Value: False 

3. Click the subform control on the main form and change the following properties:




   Form: MyForm Subform
   OnEnter: Subform Flag.Set
   OnExit: Subform Flag.UnSet 

4. Add the following macro action to the top of the macro that is attached to the OnEnter or OnExit property of the first control in the tab order of the subform. The macro will not perform any other actions if the subform flag is not set.




   Condition                       Action
   -----------------------------------------
   Parent![Subform Flag] = False   StopMacro 

MORE INFORMATION

Steps to Reproduce Behavior

1. Open the sample database Northwind.mdb and create the following macro called Test:




   MacroName     Action
   --------------------
   Test          MsgBox

   Test Actions
   --------------------
   MsgBox
      Message: Testing! 

2. Open the Orders Subform form and change the OnEnter and OnExit properties of the ProductID box to Test, as follows:




   Form: Orders Subform
   OnEnter: Test
   OnExit: Test 

3. Save the Orders Subform form, open the Orders form, and move among the records. Note that the message "Testing!" appears twice for each record.

Additional query words: exit enter prb

Keywords : kbdta FmsEvnt
Version : WINDOWS:2000
Platform : WINDOWS
Issue type : kbprb