How To Call a New 32-bit API from a 16-bit Application (125674)
The information in this article applies to:
- Microsoft Win32 Application Programming Interface (API), when used with:
This article was previously published under Q125674 SUMMARY
Windows 95 supports a new set of APIs for 32-bit applications. These APIs
are exported by USER32, GDI32, KERNEL32, and so on. In Windows 95, some of
these new APIs are also exported by the 16-bit counterpart DLLs in the
system such as USER16, GDI16, and so on. But 16-bit applications running on
Windows 95 should not call these new APIs from the 16-bit system DLLs
because these calls are not unsupported and might be removed from the
16-bit system DLLs in the future.
MORE INFORMATION
APIs such as WindowFromDC(), SetWindowRgn(), SetForeGroundWindow(), and so
on for 16-bit USER window management and PolyBezier(), PolyBezierTo(), and
so on for 16-bit GDI graphics management are exported from the 16-bit
system DLLs.
Even though these APIs are intended for 32-bit applications, the 16-bit
system DLLs export some of them. 16-bit Windows 95 Applications should not
call them. They are not supported and the APIs will not work as intended.
If Windows 95 Applications need to use these APIs, port the 16-bit
application to 32-bit. This is the best solution and is the one that
Microsoft recommends. One addtional solution is to write a 32-bit DLL that
actually calls the 32-bit API; then the 16-bit application can thunk into
this 32-bit DLL. However, Microsoft strongly discourages developers from
having applications thunk into sytem DLLs (16- or 32-bit).
| Modification Type: | Minor | Last Reviewed: | 6/29/2004 |
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| Keywords: | KB125674 |
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