Using callback to display filenames from external decompression dll in Inno Setup

Question

Originally asked here, but was asked to submit it as a separate question.

I have the following dll coded in C below that I\'m using in an Inno Setup Installer to ext

Answer 1

Have a look at the example script included with InnoTools Callback.

It's pretty straightforward, you just declare a procedure like this (again, assuming that you're using ANSI Inno -- some of the types would have to be changed for the Unicode version):

[Code]
type
    TMyCallback = procedure(Filename: PChar);

function WrapMyCallback(Callback: TMyCallback; ParamCount: Integer): LongWord;
    external 'WrapCallback@files:innocallback.dll stdcall';

procedure DoSomethingInTheDll(Blah: Integer; Foo: String; ...; Callback: LongWord);
    external 'DoSomethingInTheDll@files:mydll.dll stdcall';

procedure MyCallback(Filename: PChar);
begin
    // do whatever, eg. update the filename label
end;

// wherever you're about to call your DLL
var Callback : LongWord;
// ...
    Callback := WrapMyCallback(@MyCallback, 1); // 1 parameter
    // pass the callback to your DLL either via a dedicated function
    // or as a parameter of your existing function
    DoSomethingInTheDll(blah, foo, ..., Callback);

On the DLL side:

typedef void (__stdcall *MyCallback)(const char *filename);

You can then declare variables of type MyCallback in function parameters and then call them as if they were native C functions, and it will run the code inside the Inno script.

void __stdcall __declspec(dllexport)
    DoSomethingInTheDll(int blah, const char *foo, ..., MyCallback callback)
{
    // ...
    callback(foo);
}