Dynamic API

[WayneA]

A port of original C code by a fella named Gerome

http://uolang.org/sourcecode/c/dynamic_api3.txt

Code Select Expand

AutoDefine "Off"
Export CallDllFx
Declare Import,LoadLibrary Alias LoadLibraryA(lpLibFileName As String),Int
Declare Import,FreeLibrary(hLibModule As Int),Int
Declare Import,GetModuleHandle Alias GetModuleHandleA(lpModuleName As String),Int
Declare Import,GetProcAddress(hModule As Int,lpProcName As String),Int
Declare CDecl Extern _sprintf(buffer As String,format As String,...)
Declare CDecl Extern _memset(dst As Pointer,value As Char,count As UInt)
Declare CallDllFx(FuncName As String,DllName As String,nArgs As Int,...),Int

CallDllFx("MessageBox","user32",4,0,"World","Hello",32)

Sub CallDllFx(FuncName As String,DllName As String,nArgs As Int,...),Int
Dim arg As Int
Dim result As Int
Dim lpAddr As UInt
Dim hInst,argtable[128],i As Int
Dim buff As String
Dim ap As Pointer
SetType ap,Int
_memset(argtable,0,Len(argtable))
buff=""
hInst=GetModuleHandle(DllName)
If hInst=NULL Then hInst=LoadLibrary(DllName)
lpAddr=GetProcAddress(hInst,FuncName)
If lpAddr=NULL Then
_sprintf(buff,"%s%s",FuncName,"A")
lpAddr=GetProcAddress(hInst,buff)
EndIf
If lpAddr=NULL Then
_sprintf(buff,"%s%s","_",FuncName)
lpAddr=GetProcAddress(hInst,buff)
EndIf
If lpAddr Then
ap=Va_Start(nArgs)
ap-=4
For i=0 to nArgs-1
ap+=4
arg=#ap
argtable[i]=arg
Next i
For i=nArgs-1 to 0 Step -1
arg=argtable[i]
_asm
push dword [ebp-4]
_endasm
Next i
_asm
call [ebp-12]
mov [ebp-8],eax
_endasm
EndIf
If hInst Then FreeLibrary(hInst)
Return result
EndSub

Special thanks to Fletchie for his assistance with the last 2 asm commands. Without his help this would not have ever worked most likely.

The original posting of this (as IBPro code) can be found here:

http://uolang.org/sourcecode/basic/dynamicapi.txt

[REDEBOLT]

May I ask:

"What is the program for, and what does it do?"

[John Syl.]

Looking at the original, it allows one to call functions from a dll using a simplified call rather than a library load and declaring of all the functions that are required normally.