INFO: Use of Allocations w/ cbClsExtra & cbWndExtra in Windows

SUMMARY

The following is an explanation of the use of the allocations with cbClsExtra and cbWndExtra?:

• cbClsExtra: Extra bytes to allocate to CLASS data structure in USER.EXE local heap when RegisterClass() is called. Accessed by Get/Set CLASS Word/Long ();.
• cbWndExtra: Extra bytes to allocate to WND data structure in USER.EXE local heap when CreateWindow() is called. Accessed by Get/Set WND Word/Long ();.

You can use these structures at your discretion and for any purpose you desire.