• Call an ActionScript function from an application
• Call an application function from a flash script

Call an ActionScript function from an application

Register your function using ExternalInterface.addCallback:

import flash.external.*;

ExternalInterface.addCallback("CallMeFromApplication", this, InternalFunction);

function InternalFunction(str: String): String {
    TextArea1.text = str;

    return "The function was called successfully";
}

Use function FPCCallFunction or FPCCallFunctionBSTR:

TCHAR szResponse[1024] = { 0 };

DWORD dwLength = sizeof(szResponse) / sizeof(szResponse[0]) - 1;

FPCCallFunction(m_hwndFlashPlayerControl, 

_T("<invoke name=\"CallMeFromApplication\" returntype=\"xml\"><arguments><string>Some text for FlashPlayerControl</string></arguments></invoke>"), 

szResponse, 

&dwLength);

AfxMessageBox(CString(_T("The function returned: ")) + szResponse);

BSTR bstrRequest = SysAllocString(L"Some text for FlashPlayerControl");

BSTR bstrResponse;

if (S_OK == 
    FPCCallFunctionBSTR(m_hwndFlashPlayerControl, 
		        bstrRequest, 
			&bstrResponse))
{
	USES_CONVERSION;

	CString str = OLE2T(bstrResponse);

	AfxMessageBox(CString(_T("The function returned: ")) + str);

	SysFreeString(bstrResponse);
}

SysFreeString(bstrRequest);

Call an application function from a flash script

Use flash.external.ExternalInterface.call:

on (click) {
    _root.TextArea1.text = flash.external.ExternalInterface.call("SomeFunction");
}

Handle notification FPCN_FLASHCALL:

LRESULT WindowProc(UINT message, WPARAM wParam, LPARAM lParam)
{
    if (WM_NOTIFY == message)
    {
        LPNMHDR lpNMHDR = (LPNMHDR)lParam;

        if (m_hwndFlashPlayerControl == lpNMHDR->hwndFrom)
            switch (lpNMHDR->code)
            {
                case FPCN_FLASHCALL:
                {
                    SFPCFlashCallInfoStruct* pInfo = (SFPCFlashCallInfoStruct*)lParam;

                    CString str;
                    str += _T("The request is: '");
                    str += pInfo->request;
                    str += _T("'");

                    AfxMessageBox(str);

                    COleDateTime now = COleDateTime::GetCurrentTime();
                    FPCSetReturnValue(m_hwndFlashPlayerControl, 
_T("<string>Current time is: ") + 
now.Format() + 
_T("\r\nThis info is returned from the handler</string>"));

                    return 1;
            }
        }
...
}