ACC: How to Dynamically Unlock a Control with a Message Box

• Microsoft Access versions 7.0, 97

SUMMARY

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

To protect the data in a control on a form from accidentally being changed, you can use a message box to prompt for verification when you try to enter data into that control. Clicking Yes in the message box unlocks the control and allows you to type.

MORE INFORMATION

Microsoft provides programming examples for illustration only, without warranty either expressed or implied, including, but not limited to, the implied warranties of merchantability and/or fitness for a particular purpose. This article assumes that you are familiar with the programming language being demonstrated and the tools used to create and debug procedures. Microsoft support engineers can help explain the functionality of a particular procedure, but they will not modify these examples to provide added functionality or construct procedures to meet your specific needs. If you have limited programming experience, you may want to contact the Microsoft fee-based consulting line at (800) 936-5200. For more information about the support options available from Microsoft, please see the following page on the World Wide Web:

   http://www.microsoft.com/support/supportnet/refguide/default.asp

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

1. Start Microsoft Access, and open the sample database Northwind.mdb.

2. Open the Categories form in Design view.

3. Click Code on the View menu, and type the following line in the Declarations section:

         Public fEditDescription As Boolean
   

4. Set the OnCurrent property of the form to the following event procedure:

         Private Sub Form_Current()
   

            ' Lock the Description control for each record.
            Me!Description.Locked = True
            fEditDescription = False
   
         End Sub
   
   

5. Open the property sheet of the Description text box, and change the Locked property to Yes.

6. Set the OnKeyDown property of Description to the following event procedure:

         Private Sub Description_KeyDown(KeyCode As Integer, _
            Shift As Integer)
   
            ' If the field is not flagged for editing, prompt the user
            ' for confirmation about unlocking the control.
            If fEditDescription = False Then
               If MsgBox("Do you want to change Description?", _
                     vbYesNo + vbQuestion + vbDefaultButton2, _
                     "Confirmation") = vbYes Then
   
                  ' If the response is Yes, unlock the field
                  ' and flag it as being edited.
                  Me!Description.Locked = False
                  fEditDescription = True
               End If
            End If
   
         End Sub
   
   

7. Switch to Form view and attempt to change the contents of Description. Note that a message box appears and asks whether you want to change Description. If you click Yes, Description is unlocked and you can edit its contents for that particular record. If you click No, Description remains locked.

REFERENCES

For more information about the MsgBox function, search the Help Index for "msgbox."

For more information about getting help with Visual Basic for Applications, please see the following article in the Microsoft Knowledge Base:

   ARTICLE-ID: Q163435
   TITLE     : VBA: Programming Resources for Visual Basic for
               Applications