How to get audio buffersize through Audio Unit RemoteIO

I finally fixed the problem by following @danomatika's suggestion!

My code is as below.

in ofApp.h file,

int ticksPerBuffer = 16; //default ticksPerBuffer
int curBufferSize = -1; //current bufferSize

in ofApp.mm file,

//-------------------------------------------------------------
void ofApp::setup() {

//setup OF sound stream
ofSoundStreamSetup(2, 1, this, 44100, ofxPd::blockSize()*ticksPerBuffer, 3);
}

//--------------------------------------------------------------
void ofApp::audioRequested(float * output, int bufferSize, int nChannels) {

if (bufferSize == curBufferSize) { //if the new bufferSize is same as the current one

    pd.audioOut(output, bufferSize, nChannels);
}
else { //if the new bufferSize is different from the current one, init pd with different ticksPerBuffer

    ticksPerBuffer = bufferSize / 64; //calculate new ticksPerBuffer

   if (pd.isInited()) {

       pd.unsubscribeAll();
       pd.removeReceiver(*this);
       pd.removeMidiReceiver(*this);
    }

    if(!pd.init(2, 1, 44100, ticksPerBuffer, false)) {
        OF_EXIT_APP(1);
    }

    // subscribe to receive source names
    pd.subscribe("blahblah1");
    pd.subscribe("blahblah2");

    // add message receiver, required if you want to receieve messages
    pd.addReceiver(*this);   // automatically receives from all subscribed sources

    // add midi receiver, required if you want to recieve midi messages
    pd.addMidiReceiver(*this);  // automatically receives from all channels

    pd.start();//turn pd dsp on

    curBufferSize = bufferSize; //set the updated bufferSize
  }

}

I tried several times to get it working.
This even works when bufferSize changes while the patch is already running. I could still run the patch without closing and re-opening the patch after the re-init. I don't know why though.

Thank you very much for your help @danomatika! I owe you so much.
Maybe you can add the code to ofxPd iOS examples for other users? it's up to you though.
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