What is DllCall in Autohotkey?

[Sabestian Caine]

I know many people have asked this question in forum. But I do not really understand the dllcalls in autohotkey even after reading documentation of dllcall and reading the tutorials like this https://autohotkey.com/board/topic/8831 ... essagebox/
Please make me understand dllcalls in simple way. Also tell me how can we use this in simple codes. I will be very thankful to you.
Thanks a lot...

[Ronins]

Every Operating System exposes some kind of functions which other applications can use. Applications can make a "Native call" to those functions. They are generally exposed in the form of library functions (DLL in case of windows). Many applications do this too. They expose some commonly used functions. This helps applications to be modular in nature. You can say that an entire working application might contain several individual modules (which might be in the form of DLLs).

Now, since these functions are exported to DLLs, we can use these functions by importing them and making a call to those functions. That's what DllCall does. Here's an example.

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DllCall("MessageBox","Uint",0,"Str","This Message is poped through DLLcall","Str","I typed that title","Uint","0x00000036L")

MessageBox is a function present in user32.dll. That DLL is preloaded in AHK, so we can call functions as shown above.
Now, as any regular function, this MessageBox function has some parameters
MSDN link shows us that the function looks like

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MessageBox(owner, text, caption, type)

These functions are written in strictly typed language (in simple terms, you have to ensure each parameter has correct type).
Therefore, we marshall
- owner as an unsigned integer (0 means no owner)
- the text as a string
- Caption as string
- type as unsigned integer (written as Long hex in the example above)

TL;DR - DLLs are libraries which may expose some functions which can be used by other applications. DllCall helps you call those functions.

[BoBo]

https://m.youtube.com/watch?v=aWEvHoRYh2U
https://m.youtube.com/watch?v=TYFiapIlk48

Does someone know what happend with "RaptorX" alias Isaias Baez??

[stretchymantis]

@Ronins, That was an incredibly awesome explanation and helped me immensely. Thank you!!!