CODEWITHSUNDEEP
androidmultithreading
npatel
npatel

Reputation: 263

Multi-threading with different Buttons view: Android

So I am writing an android code where there are 3 buttons:record, pause, take frame. Record button records a video, pause button pauses the video displaying in VideoView and Take frame button shows the paused frame in imageView. Now I need 3 threads - one main thread is for user interaction (pause button), one sub thread records the video(record button) and second sub thread saves the frame(take frame button).

protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);

            mvideoview = (VideoView) findViewById(R.id.videoView);
            imgview = (ImageView) findViewById(R.id.imageView);
            mrecord = (Button) findViewById(R.id.button);
            mpause = (Button) findViewById(R.id.button2);
            mtakeframe = (Button) findViewById(R.id.button4);

            mrecord.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                            dispatchTakeVideoIntent();
                            mvideoview.start();
                        }
            });

            mpause.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    mvideoview.pause();
                }
            });


            mtakeframe.setOnClickListener(new View.OnClickListener() {

                @Override
                public void onClick(View view) {
                            Bitmap bmp = takeFrame();
                            imgview.setImageBitmap(bmp);
                        }
                    });
        }

        private void dispatchTakeVideoIntent() {
            //code directs towards the video recorder screen
        }

        protected void onActivityResult(int requestcode, int resultcode, Intent intent) {
            //recorded video sent back and its path stored
        }

        public Bitmap takeFrame() {
            //paused frame shown in imageView
        }

I tried putting different threads at onClick(View view) of different buttons but at the end the application crashes saying the error "Only the original thread that created a view hierarchy can touch its views." And also if I want to add one more button that is PLAY(plays the paused video) then how should I write it, I can't understand. Can someone help me here in how to thread such a program in Android?

Upvotes: 2

Views: 66

Answers (1)

Muthukrishnan Rajendran
Muthukrishnan Rajendran

Reputation: 11642

View object can modify or do any action only by UI thread If another thread tries to process on the View object, it should call like this,

runOnUiThread(new Runnable() {
            @Override
            public void run() {
                // do the view operation here
            }
        });

For more information you can refer this, this

Upvotes: 2

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