DOC: Incorrect Prototype & Memory Allocation for PX_Blob (135630)


The information in this article applies to:

  • The Microsoft Foundation Classes (MFC), when used with:
    • Microsoft OLE Control Developer's Kit (CDK)
This article was previously published under Q135630

SUMMARY

The documentation for the prototype of PX_Blob in the CDK Books Online is shown incorrectly as: 
   BOOL PX_Blob( CPropExchange* pPX, LPCTSTR pszPropName,
 
      HGLOBAL*& hBlob, HGLOBAL hBlobDefault = NULL );
The actual prototype as shown in the CDK source code in Afxctl.h is: 
   BOOL PX_Blob(CPropExchange* pPX, LPCTSTR pszPropName, HGLOBAL& hBlob,
 
      HGLOBAL hBlobDefault = NULL);

MORE INFORMATION

Note that the third parameter is incorrectly listed as HGLOBAL*& hBlob in the documentation and should instead be HGLOBAL& hBlob as shown in the actual prototype.

There is also another error in the PX_Blob remarks section of the documentation. It states the following incorrect information:

Note that PX_Blob will allocate memory, using the new operator, when loading BLOB-type properties. Therefore, the destructor of your control should call delete on any BLOB-type property pointers to free up any memory allocated to your control.

This correct documentation should be as follows:

Note that PX_Blob will allocate memory, using the Windows GlobalAlloc API, when loading BLOB-type properties. You are responsible for freeing this memory. Therefore, the destructor of your control should call GlobalFree on any BLOB-type property handles to free up any memory allocated to your control.

The problems described in this article were fixed in Visual C++, 32-bit edition, version 4.0 and later.
Modification Type:MinorLast Reviewed:8/18/2005
Keywords:kbCtrl kbdocfix KB135630
©2004 Microsoft Corporation. All rights reserved.