이벤트 리스너 질문드립니다! [closed]

Question

public void surfaceChanged(SurfaceHolder holder, int format, int width, int height)
        {
            camera.startPreview();

            auto_Focusing(camera);

            final CameraSurfaceView cameraView = new CameraSurfaceView(getApplicationContext());
            final FrameLayout previewFrame = (FrameLayout) findViewById(R.id.previewFrame);

            previewFrame.setOnTouchListener(new OnTouchListener()//231라인
            {
                @Override
                public boolean onTouch(View v, MotionEvent event)
                {
//                    if(event.getAction()==MotionEvent.ACTION_UP)
//                    {
//                        auto_Focusing(camera);
//                    }
                    return false;
                }
            });

            Binarization(camera, holder);
        }

 

코드는 이렇구요

증상은 앱을 실행시키면 강제로 종료됩니다.

java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.FrameLayout.setOnTouchListener(android.view.View$OnTouchListener)' on a null object reference
                                                                          at com.example.ai.ex.MainActivity$CameraSurfaceView.surfaceChanged(MainActivity.java:231)

PS. xml에 FrameLayout 의 id값이 previewFrame으로 되어 있습니다.