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                             DECLARE AND WIN32API
                                 January 2017
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                                    CCB



1. THE DECLARE STATEMENT SYNTAX (from dv_foxhelp9.chm):

     DECLARE [cFunctionType] FunctionName IN LibraryName [AS AliasName]
        [cParamType1 [@] ParamName1, cParamType2 [@] ParamName2, ...]

     IN LibraryName
     Specifies the name of the external shared library containing the function specified with FunctionName.
     If you specify WIN32API for the LibraryName,
     Visual FoxPro searches for the 32-bit Windows .dll function in:
     1, Kernel32.dll,
     2, Gdi32.dll,
     3, User32.dll,
     4, Mpr.dll,
     5, and Advapi32.dll. 


2. REFERENCE CODE:

     There is a small problem, in fact,
     Visual FoxPro 9.0 (and before) searches for the 32-bit Windows .dll function in:
     1, User32.dll,
     2, Gdi32.dll,
     3, Kernel32.dll,
     4, Advapi32.dll,
     5, and Mpr.dll.

     In VFP 9.0 (and before), usually, there is no windows api function in 2 (or more) .dlls,
     so this is not a big problem.

     In VFP Advanced (x64), there are some windows api functions in 2 (or more) .dlls.
     For example,
     there is a RegOpenKeyExA function in advapi32.dll,
     and there is a RegOpenKeyExA function in kernel32.dll.

     Usually, We want call RegOpenKeyExA function in advapi32.dll, not in kernel32.dll.

     So VFP Advanced (x64) has changed it to:
     Visual FoxPro Advanced searches for the 64-bit Windows .dll function in:
     1, Advapi32.dll,
     2, User32.dll,
     3, Gdi32.dll,
     4, Kernel32.dll,
     5, and Mpr.dll.


3. REFERENCE WINDOWS APIS:

     The following windows api functions (Reg*) both in advapi32.dll and kernel32.dll:
     RegCloseKey
     RegCreateKeyExA
     RegCreateKeyExW
     RegDeleteKeyExA
     RegDeleteKeyExW
     RegDeleteTreeA
     RegDeleteTreeW
     RegDeleteValueA
     RegDeleteValueW
     RegDisablePredefinedCacheEx
     RegEnumKeyExA
     RegEnumKeyExW
     RegEnumValueA
     RegEnumValueW
     RegFlushKey
     RegGetKeySecurity
     RegGetValueA
     RegGetValueW
     RegLoadKeyA
     RegLoadKeyW
     RegLoadMUIStringA
     RegLoadMUIStringW
     RegNotifyChangeKeyValue
     RegOpenCurrentUser
     RegOpenKeyExA
     RegOpenKeyExW
     RegOpenUserClassesRoot
     RegQueryInfoKeyA
     RegQueryInfoKeyW
     RegQueryValueExA
     RegQueryValueExW
     RegRestoreKeyA
     RegRestoreKeyW
     RegSaveKeyExA
     RegSaveKeyExW
     RegSetKeySecurity
     RegSetValueExA
     RegSetValueExW
     RegUnLoadKeyA
     RegUnLoadKeyW

     Usually, these windows api functions in advapi32.dll will jump to the same name windows api functions in kernel32.dll.
     In other words, these windows api functions in advapi32.dll is the same as these windows api functions in kernel32.dll.

     But, it is not always same.
     For example,
     the sprintf function in ntdll.dll is not the same as the sprintf function in msvcrt.dll.
     In fact, the sprintf function in ntdll.dll is simpler, it does not supports some format-control strings such as %f.


4. OTHER:

     For reference only, there is no guarantees.

     Any questions or suggestions, please e-mail to ccb2000@163.com.