BUG: Data Control Errors Do Not Populate Error Object

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

SYMPTOMS

A "Type Mismatch" error is generated when a control is bound to a field with an incompatible type, but the Error object is not populated when it is examined in the Data Control Error event.

CAUSE

This is a limitation of the Data Control in Visual Basic version 4.0. When the DAO generates an error, the Error object is cleared when the Error event for the Data Control is fired.

RESOLUTION

For more information, search for the "Trappable Data Access Errors" in the Help menu when building your error handling code.

You are not prevented in any way from writing the exact same error handling code you would have written previously. Note that the error number passed as a parameter to the Data Control's Error will be correct. Only the Error object is affected. Also, most error checking in the DAO will be unaffected. If a Field or Database object generates the error, then the Error object is properly populated.

STATUS

Microsoft has confirmed this to be a problem in the Microsoft products listed at the beginning of this article. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

Steps to Reproduce Problem

1. Start a new project in Visual Basic. Form1 is created by default.

2. Add a data control (Data1) and a check box (Check1) to Form1.

3. Set the following properties for the controls:

      Control   Property       Value
      -----------------------------------
      Data1     Databasename   Biblio.MDB
      Data1     RecordSource   Authors
      Check1    DataSource     Data1
      Check1    DataField      Author
   
   

4. Add the following code to the Data1_Error procedure.

      Private Sub Data1_Error(DataErr As Integer, Response As Integer)
         Debug.Print "DataErr = "; DataErr
         Debug.Print "Description = "; Err.Description
         Debug.Print "HelpContext = "; Err.HelpContext
         Debug.Print "HelpFile = "; Err.HelpFile
         Debug.Print "Number = "; Err.Number
         Debug.Print "Source = "; Err.Source
         'Response = vbDataErrContinue
      End Sub
   
   

5. Start the program by clicking Start on the Run menu or by pressing the F5 key.

   DataErr = 13
   Description =
   HelpContext = 0
   HelpFile =
   Number = 0
   Source =