DLL question

[magician13134]

How do you know the functions inside of a DLL? IS there a program to view them like the COM/OLE viewer? Like in this:

DllCall("user32.dll", "int", "ShowCursor", "int", 0)

This hides the cursor. Now I know CyberSlug is a genius, but he didn't just guess that "ShowCursor" was in user32. How do you find these? Thanks!

[The Kandie Man]

Looking at the windows header files for declared functions is one way. Another way is to go on MSDN and simply look at the win32api.

Win32API:

http://msdn.microsoft.com/library/default....i_reference.asp

ShowCursor function:

http://msdn2.microsoft.com/en-us/library/ms648396.aspx

- The Kandie Man ;-)

Edited May 29, 2007 by The Kandie Man

[xcal]

This is a handy app, too: DLL Explorer Viewer

[magician13134]

Thanks both of you!

[magician13134]

Ok... well... I'm having trouble figuring out how to use them... For instance I found one in user32.dll called GetCursorPos, and I know this is like MouseGetPos(), but how would I actually use the dll? can someone give me an example?

Edited May 31, 2007 by magician13134

[PaulIA]

Ok... well... I'm having trouble figuring out how to use them... For instance I found one in user32.dll called GetCursorPos, and I know this is like MouseGetPos(), but how would I actually use the dll? can someone give me an example?

$tPoint = DllStructCreate("int X; int Y")
DllCall("User32.dll", "int", "GetCursorPos", "ptr", DllStructGetPtr($tPoint))
ConsoleWrite("Cursor X position: " & DllStructGetData($tPoint, "X") & @CR)
ConsoleWrite("Cursor Y position: " & DllStructGetData($tPoint, "Y") & @CR)

[magician13134]

$tPoint = DllStructCreate("int X; int Y")
DllCall("User32.dll", "int", "GetCursorPos", "ptr", DllStructGetPtr($tPoint))
ConsoleWrite("Cursor X position: " & DllStructGetData($tPoint, "X") & @CR)
ConsoleWrite("Cursor Y position: " & DllStructGetData($tPoint, "Y") & @CR)

Hmmm.... I just get this no matter what:

Cursor X position: 0

Cursor Y position: 0

[PaulIA]

Hmmm.... I just get this no matter what:

Cursor X position: 0

Cursor Y position: 0

Need latest version of AutoIt and make sure your mouse isn't in upper left hand corner of the screen.

[magician13134]

I do and it's not... oh well, I found a couple other example on the forums

[PaulIA]

I do and it's not... oh well, I found a couple other example on the forums

If you're not getting the right results from these 4 lines of code, one of the following is true:

1. You don't have the latest production version of AutoIt

2. You mangled the original script when you copied it

3. You're mouse is in the upper left hand corner of your screen

4. Some other really n00b thing that I haven't thought of yet

You pick.

[magician13134]

If you're not getting the right results from these 4 lines of code, one of the following is true:

1. You don't have the latest production version of AutoIt

2. You mangled the original script when you copied it

3. You're mouse is in the upper left hand corner of your screen

4. Some other really n00b thing that I haven't thought of yet

You pick.

Uhhhh... NUMBER 1! I PICK NUMBER 1! Ok... sorry about that. It works... now can someone explain why? What exactly it all does?

[PaulIA]

Uhhhh... NUMBER 1! I PICK NUMBER 1! Ok... sorry about that. It works... now can someone explain why? What exactly it all does?

NP. The MSDN link for GetCursorPos looks like this:

BOOL GetCursorPos(LPPOINT lpPoint);

So we know that the function returns a BOOL value (which is just an integer), takes a pointer to a POINT structure as input and is defined in User32.dll. If you look on MSDN, a POINT structure looks like this:

struct tagPOINT { 
  LONG x; 
  LONG y; 
}

So, back to the code that I gave you:

$tPoint = DllStructCreate("int X; int Y")
DllCall("User32.dll", "int", "GetCursorPos", "ptr", DllStructGetPtr($tPoint))
ConsoleWrite("Cursor X position: " & DllStructGetData($tPoint, "X") & @CR)
ConsoleWrite("Cursor Y position: " & DllStructGetData($tPoint, "Y") & @CR)

So, after using DllStructCreate to build a POINT structure, we call DllCall with the following:

1. The Dll where GetCursorPos is defined (User32.dll)

2. The return type expected (BOOL = "int")

3. The name of the Dll function (GetCursorPos)

4. A pointer to our POINT structure

When called, GetCursorPos get's the global cursor position and places it in our POINT structure, using the pointer that we passed. On return, we use DllStructGetData to extract the X and Y positions. Simple right?

[PsaltyDS]

Uhhhh... NUMBER 1! I PICK NUMBER 1! Ok... sorry about that. It works... now can someone explain why? What exactly it all does?

Not a DLL-type myself, but I'll take a shot at it for the educational value:

$tPoint = DllStructCreate("int X; int Y")
DllCall("User32.dll", "int", "GetCursorPos", "ptr", DllStructGetPtr($tPoint))
ConsoleWrite("Cursor X position: " & DllStructGetData($tPoint, "X") & @CR)
ConsoleWrite("Cursor Y position: " & DllStructGetData($tPoint, "Y") & @CR)

First you reserve some space in memory for various values. This will be the "structure". It can contain lots of different type of values, but in this case simply reserves memory space for two integers to be called "X" and "Y". The pointer to their memory space is saved as $tPoint.

Next you call the User32.dll and pass it parameters as specified by it's code (completely different from dll to dll).

Of the parameters, the first is most confusing to me. Integer is obviously meant by "int", but what is that for, return code?

The second parameter is easy. "GetCursorPos" is a pretty plain-language verb telling the .dll what to do.

Third one seems to only tell what type the fourth is - it's a pointer ("ptr") to the memory structure we want the answer put in.

And fourthly, the actual pointer that tells it where in memory to put our answer.

The two lines after that that take advantage of the names given our structure elements "X" and "Y" to read out their values.

I just expended everything I know about .dll's, and I know it aint much, but we can keep learning from there...

Edit: PaulIA! Where's the fun in us dummies figuring it out if you smart people are just going to give away the answers like that!

Edited June 1, 2007 by PsaltyDS

[PaulIA]

Not a DLL-type myself, but I'll take a shot at it for the educational value:

$tPoint = DllStructCreate("int X; int Y")
DllCall("User32.dll", "int", "GetCursorPos", "ptr", DllStructGetPtr($tPoint))
ConsoleWrite("Cursor X position: " & DllStructGetData($tPoint, "X") & @CR)
ConsoleWrite("Cursor Y position: " & DllStructGetData($tPoint, "Y") & @CR)

First you reserve some space in memory for various values. This will be the "structure". It can contain lots of different type of values, but in this case simply reserves memory space for two integers to be called "X" and "Y". The pointer to their memory space is saved as $tPoint.

Next you call the User32.dll and pass it parameters as specified by it's code (completely different from dll to dll).

Of the parameters, the first is most confusing to me. Integer is obviously meant by "int", but what is that for, return code?

The second parameter is easy. "GetCursorPos" is a pretty plain-language verb telling the .dll what to do.

Third one seems to only tell what type the fourth is - it's a pointer ("ptr") to the memory structure we want the answer put in.

And fourthly, the actual pointer that tells it where in memory to put our answer.

The two lines after that that take advantage of the names given our structure elements "X" and "Y" to read out their values.

I just expended everything I know about .dll's, and I know it aint much, but we can keep learning from there...

Edit: PaulIA! Where's the fun in us dummies figuring it out if you smart people are just going to give away the answers like that!

Dlls? Fun? What are YOU drinking (and where do I get some)?

"GetCursorPos" a verb? Well, more like the name of a function inside the Dll itself. It's like calling a UDF in AutoIt. Each one has it's own name, return type and parameter list. When you use DllCall, it loads the Dll, finds the function entry point, calls the function with the parameters that you supply and then returns the results. Yes, Jon is a genius.

[PsaltyDS]

Dlls? Fun? What are YOU drinking (and where do I get some)?

"GetCursorPos" a verb? Well, more like the name of a function inside the Dll itself. It's like calling a UDF in AutoIt. Each one has it's own name, return type and parameter list. When you use DllCall, it loads the Dll, finds the function entry point, calls the function with the parameters that you supply and then returns the results. Yes, Jon is a genius.

Did the BOOL (= "int") return go anywhere? Or would that be captured by:

$iRetCode = DllCall("User32.dll", "int", ...)

[PaulIA]

Did the BOOL (= "int") return go anywhere? Or would that be captured by:

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A 1 means it worked and a 0 means you did something really bad.

[PsaltyDS]

Thanks!

I used 'ta couldn't spell DLL, now I own 'em. Thanks to PaulIA!

[magician13134]

Hey, can I ask for help with one more issue? I want to user user32's GetWindowRect... any idea how? I've tried using the help file and searching the forums... this is what I've got, but it always returns 0, so I know it's wrong...

$win = WinGetHandle("")
$str        = "int;ubyte;uint;char"
$a          = DllStructCreate($str)
$dll = DllCall("user32.dll", DllStructGetPtr($a), "GetWindowRect", "hwnd", $win)
MsgBox(0, "", $int)

Edited June 10, 2007 by magician13134

[PaulIA]

Hey, can I ask for help with one more issue? I want to user user32's GetWindowRect... any idea how? I've tried using the help file and searching the forums... this is what I've got, but it always returns 0, so I know it's wrong...

$win = WinGetHandle("")
$str        = "int;ubyte;uint;char"
$a          = DllStructCreate($str)
$dll = DllCall("user32.dll", DllStructGetPtr($a), "GetWindowRect", "hwnd", $win)
MsgBox(0, "", $int)

Defined in the A3LWinAPI.au3 module of Auto3Lib. Download a copy and save yourself a lot of grief.

[magician13134]

I've tried that and it doesn't work. I get errors for 99% of them... I have the LATEST installed and I did everything just as it said... but it just doesn't work... (I'm talking about Auto3Lib)