C / C++ / MFC

1. Check the encoding of your QR data. Are there extra (non-Arabic) bytes, or anything else?
2. The data that you are receiving from the serial port is 8-bit bytes. It must somehow be converted to Unicode characters, according to the encoding determined in stage (1).

1. Move this question over to the Visual Basic forum. People there may be better able to help you with your code.

unsigned long _beginthreadex( void *security, unsigned stack_size, unsigned ( __stdcall *start_address )( void * ), void *arglist, unsigned initflag, unsigned *thrdaddr );

uintptr_t _beginthreadex( // NATIVE CODE
   void *security,
   unsigned stack_size,
   unsigned ( __stdcall *start_address )( void * ),
   void *arglist,
   unsigned initflag,
   unsigned *thrdaddr
);

#include <process.h>  
class foo
{
public:
	void startTheThread()
	{
		// Start the thread for the sendData (we send "this" in as a parameter for shim)
        // The shim code is a static block for all your class instances hence &foo::sendData 
        // It creates a class member call from the value of "this" passed in 
		sendHandle = _beginthreadex(0, 0, &foo::sendData, this, 0, &this->m_sendThreadId);
	}
private:
	void sendDataMemberCall()
	{
		/* All the real send code goes here */
	}

	static unsigned __stdcall sendData(void *p_this)
	{
		/* This is just a shim to convert a thread call to a member function call */
		foo* p_foo = static_cast<foo*>(p_this);
		p_foo->sendDataMemberCall(); // call Non-static member function!
		return 0;
	}
	uintptr_t sendHandle;
	unsigned m_sendThreadId;
};

void sendDataMemberCall()

void sendDataMemberCall (foo* this);

sendDataMemberCall (&foo1);
sendDataMemberCall (&foo2);