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Attachment.BeforeUpdate Event (Access)

The BeforeUpdate event occurs before changed data in a control or record is updated.

Version Added: Access 2007

expression .BeforeUpdate(Cancel, )

expression A variable that represents an Attachment object.

Parameters

Name

Required/Optional

Data Type

Description

Cancel

Required

Integer

The setting determines if the BeforeUpdate event occurs. Setting the Cancel argument to True (–1) cancels the BeforeUpdate event.

Return Value

nothing

Changing data in a control by using Visual Basic or a macro containing the SetValue action doesn't trigger these events for the control. However, if you then move to another record or save the record, the form's BeforeUpdate event does occur.

The BeforeUpdate event applies only to controls on a form, not controls on a report.

To run a macro or event procedure when this event occurs, set the BeforeUpdate property to the name of the macro or to [Event Procedure].

The BeforeUpdate event is triggered when a control or record is updated. Within a record, changed data in each control is updated when the control loses the focus or when the user presses ENTER or TAB. When the focus leaves the record or if the user clicks Save Record on the Records menu, the entire record is updated, and the data is saved in the database.

When you enter new or changed data in a control on a form and then move to another record or save the record by clicking Save Record on the Records menu, the AfterUpdate event for the form occurs immediately after the AfterUpdate event for the control. When you move to a different record, the Exit and LostFocus events for the control occur, followed by the Current event for the record you moved to, and the Enter and GotFocus events for the first control in this record. To run the AfterUpdate macro or event procedure without running the Exit and LostFocus macros or event procedures, save the record by using the Save Record command on the Records menu.

BeforeUpdate macros and event procedures run only if you change the data in a control. This event does not occur when a value changes in a calculated control. BeforeUpdate macros and event procedures for a form run only if you change the data in one or more controls in the record.

If the user enters a new value in the control, the OldValue property setting isn't changed until the data is saved (the record is updated). If you cancel an update, the value of the OldValue property replaces the existing value in the control.

You often use the BeforeUpdate event to validate data, especially when you perform complex validations, such as those that:

  • Involve conditions for more than one value on a form.

  • Display different error messages for different data entered.

  • Can be overridden by the user.

  • Contain references to controls on other forms or contain user-defined functions.

A run-time error will occur if you attempt to modify the data contained in the control that fired the BeforeUpdate event in the event's procedure.

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