PRB: VB Registry Functions Are Limited with Nested Settings

• Standard, Professional, and Enterprise Editions of Microsoft Visual Basic for Windows, 16-bit and 32-bit, version 4.0

SUMMARY

The SaveSetting statement and GetSetting function in Visual Basic 4.0 for Windows are used to create and retrieve information from nested levels in the Registry. However, the related DeleteSetting statement does not handle these nested settings. The GetAllSettings function also has this limitation.

SYMPTOMS

Error 5 - Invalid Procedure Call appears when the DeleteSetting is attempted.

STATUS

This behavior is by design. The ability to create and retrieve values from nested levels in the registry was a fortunate byproduct of the design of the set and get functions, and this wasn't extended to include all of the related registry functions.

WORKAROUND

Use more than one DeleteSetting statement to remove sections of the nested keys before removing the top level key, rather than attempting to remove the top key in isolation.

For example, in the following, do not use:

   DeleteSetting "Test1"

   DeleteSetting "Test1\Test2"
   DeleteSetting "Test1"

For more information on the Registry API functions, please see the following article in the Microsoft Knowledge Base:

   ARTICLE-ID: Q145679
   TITLE     : How to Use the Registry API to Save and Retrieve Setting

MORE INFORMATION

Steps to reproduce problem

1. Start Visual Basic 4.0, 32-bit version. Form1 is created by default. Place two command buttons on the form. Add the following code to Form1:

      Private Sub Command1_Click()
          SaveSetting "Test1", "Test2\Test3", "TestKey", "TestValue"
      End Sub
   
      Private Sub Command2_Click()
          DeleteSetting "Test1"
      End Sub
   
   

2. On the Run menu, choose Start, or press F5 to begin the application. Choose Command1 to add the nested keys to the registry. Open the Registry Editor and confirm that the information has been correctly added under the key HKEY_CURRENT_USER\Software\VB and VBA Program Settings.

3. Return to the running application and choose Command2. VB will raise error 5 - Invalid Procedure Call. To view the workaround, stop the program and replace the single call to DeleteSetting with the two calls listed in the Workaround section above. Rerun the program and choose the second command button again. Use the Registry Editor to see that the keys have been removed correctly.