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Hi,

I'm sure it has been asked thousand times. But I can't find a tutorial how to do it. Sorry.
I have a DLLCall that expects an struct:How do i calculate the right Capacity? And how do I afterwards get the data with NumGet() out of it? Thanks.

If you know a tutorial on structs in AHK, please point me to it.

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Ciao
toralf

I found one tutorial: http://www.autohotkey.com/forum/topic35843.html
But I'm not so sure I understood.

Here is what i THINK the code is supposed to be...

Since in the struct are two pointers for strings and one is an integer, the capacity should be 12 (3*4)

Then the DLL is called with the address of the BASS_DEVICEINFO struct


The pointers to the strings and the number can then be retrieved with NumGet from the structUnfortunately that doesn't work. :|
Any help?

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Ciao
toralf

Do the pointers returned in that struct point to memory locations inside your script's memory space or elsewhere?

I'm guessing that those strings are in some other process an you'll need ReadProcessMemory to get them.

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Ternary (a ? b : c) guide     TSV Table Manipulation Library
Post code inside [code][/code] tags!

Could be. I'm not sure.
The DLL is loaded with the AHL script.
How could I test this?

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Ciao
toralf

Moin,

wenn es ANSI ist, probier mal sowas / if it is ANSI, you might try something like this:

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nick

Thanks a lot,
That solved it.

Is there a shorter way to do it?
It seems to be quite complicated.
First to create a Var with a capacity of the string length the pointer is pointing at.
Then copying the string the pointer is pointing at into the var.

If not, I can live with it.

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Ciao
toralf

You could always create a function to retrieve the string. Here's a trick:
MulDiv returns p as-is, but DllCall sees the return type is "str" so interprets the return value (p) as a string pointer.
Tested okay with AutoHotkey v1.0.48.05 and ANSI/Unicode builds of AutoHotkey_L. (Btw, AutoHotkey_L and AutoHotkeyU have StrGet() built-in, but it is currently incapable of retrieving ANSI strings in Unicode builds.)

Thanks a lot Lexikos. DllCall are not my cup of tea....

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Ciao
toralf

...instead of simply marking this solved, could someone create or point me to current struct handling info/code? I know there's ahkstructlib, last I checked no one has updated it in a while...is that currently the best option?...still?...would someone please make a full struct handling API? I don't like using NumGet() directly, cuz you need to know the offsets...plus most structs have LPSTR fields, then you only have a pointer to a string & need to do "something else" to get/set that string...I'm pretty good savvy with AutoHotkey/computers, but structs have been giving me fits for years...MSDN or Google will tell me a struct field is LPSTR (or DWORD) & in NumGet() I'm supposed to know to use UInt or <whatever>? what about LPCSTR? is that UInt too?

Have a look at this ---> Easy WinAPI - WinAPI Parser, DllCall with single hotkey

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My Ahk Site

Thanks, but no source makes it less-than-useful. Anything else?...with source?

Did you see this part?


And they both have source

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My Ahk Site

...yes, I know about StructParser (& that's actually pretty helpful {it's just not a Struct API}) & I already mentioned that I know about ahkstructlib. Maybe I'll smash them together & try to make my own version of struct-handling code? So I guess the answer is no, there's nothing new in the vanilla-AHK struct-handling front? Actually, if I hold out long enough, I'll just use IronAHK & (I'm guessing) that should have all the struct-handling I need!