Function Pointer From String (static class member)

vezprog

Hi,

What I am trying to do, is create a main() function with custom input arguments in a dll, and wrap it in a thread using QtConcurrent.

I could do this easily if I just made a class, but I want to dynamically call the main function without having to create a class object to pass into QtConcurrent...

So for example, I want a function in the hello.dll called main_ride_bike(BikerInfo *info), where the BikerInfo class contains a couple attributes about the biker, like how far he wants to go (integer), the bikers name (QString), etc.
@
// create function name
QString processName = "main_ride_bike"; // function in dll

// create biker info
BikerInfo *info = new BikerInfo(this);
info->bikerName = "mike";
info->distanceToGo = 100;

// start thread using 'main' function in dll
QFuture <void> rideBike = QtConcurrent::run(processName, info);
@

How could I construct the Qt Dll to do so?

mcosta

Hi,

in order to create correctly a shared library read "here":http://qt-project.org/doc/qt-5.1/qtdoc/sharedlibrary.html

vezprog

I figured out most of what I was trying to do with the dll.

My only issue now is trying to convert a string to a function pointer. Unfortunately, I don't believe I will be able to use a 'reflection' like technique in c++.

Thank you again.

mcosta

The question is: "Why do you need use a string"?
If you really needs it, Read about QLibrary class in order to load the library at runtime.

Gojir4

Hi,
Converting a string to a function pointer is not possible directly, what is possible is to use "QMetaObject::invokeMethod()":http://qt-project.org/doc/qt-5.1/qtcore/qmetaobject.html#invokeMethod to call a method using its name in a string. But unfortunately this does not return a pointer to the function, so I'm not sure that this will match with you requirements.

Maybe this post could help : "Call a function or methods dynamically":http://qt-project.org/forums/viewthread/17773

edit: There is certainly a way to run QMetaObject::invokeMethod in a different thread.