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Android, how to update value of ProgressBar?

In my activity there is a ProgressBar. When you get started, I will check the value get from another place and upgrade to the ProgressBar. Here is my code:

final ProgressBar progressBar = (ProgressBar) findViewById(R.id.progressBar_detail);
final TextView progressText = (TextView) findViewById(R.id.progressText_detail);
final ImageView btnCancel = (ImageView) findViewById(R.id.imgCancel_detail);
progressBar.setVisibility(View.VISIBLE);
progressText.setVisibility(View.VISIBLE);
btnCancel.setVisibility(View.VISIBLE);
Thread t = new Thread() {
    public void run() {
        ((Activity) ctx).runOnUiThread(new Runnable() {
            public void run() {
                int oldProgress = 0;
                while (progressBar.getProgress() < 100) {
                    int value = Downloader.progress.get(gameId+ "");
                    if (value != oldProgress) {
                        oldProgress = value;
                        progressBar.setProgress(value);
                        progressText.setText(value + " %");
                    }
                }
            }
        });
    }
};
t.start();

I get the value of the ProgressBar from int value = Downloader.progress.get(gameId)and this is correct. But when I run this code, the activity does not respond and shows nothing (but the application does not crash). It seems that the thread is updating the ProgressBar and blocking the UI thread, so the activity layout is not displayed.

What happened to my code? What is the correct way to update the ProgressBar in this situation?

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4 answers

while (progressBar.getProgress() < 100) ( runOnUiThread), ( ) , .

:

  • runOnUiThread , , de runOnUiThread. , CPU, . , . :

    Thread t = new Thread() {
    public void run() {
    int oldProgress = 0;

    while (progressBar.getProgress() < 100) {
            ((Activity) ctx).runOnUiThread(new Runnable() {
                public void run() {
                    int value = Downloader.progress.get(gameId+ "");
                    if (value != oldProgress) {
                        oldProgress = value;
                        progressBar.setProgress(value);
                        progressText.setText(value + " %");
                    }
                }
            }
            Thread.sleep(500);
        }
    });
}

    };

  • , ( ) . .

+10

:

    int currentPosition=0;
    int total=mediaPlayer.getDuration();
    while(mediaPlayer!=null && currentPosition<total){
        try{
            if(progressEnable){
                Thread.sleep(1000);
                currentPosition=mediaPlayer.getCurrentPosition();
                long pos=1000L * currentPosition/total;
                Log.d("thread pos", pos+"");
                progressSeekBar.setProgress((int) pos);
            }
        }
        catch (Exception e) {
        }
    }

progressEnable :

private boolean progressEnable=true;
+1

I usually use this code:

private int mProgressStatus;
private Handler mHandler = new Handler();

public void startProgress(View view) {
    final ProgressBar progressBar = (ProgressBar) findViewById(R.id.horizontal_progress);
    mProgressStatus = 0;
    progressBar.setProgress(mProgressStatus);

    //progressBar.setVisibility(View.VISIBLE);
    new AsyncTask<Void, Void, Void>() {
        @Override
        protected Void doInBackground(final Void... params) {
            while (mProgressStatus < 100) {
                try {
                    Thread.sleep(500);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                mProgressStatus += 15;
                mHandler.post(new Runnable() {
                    public void run() {
                        progressBar.setProgress(mProgressStatus);
                    }
                });
            }
            return null;
        }

    }.execute();
}

Hope this helps

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You can automatically push the progress bar with RXJava.

@Override
protected void onAttachedToWindow() {
    super.onAttachedToWindow();
    if (autoProgress) {
        autoProgressSubscriber = Observable.interval(0, 1000/60, TimeUnit.MILLISECONDS) //~60fps
                    .map(index -> calculateAutoProgress())
                    .subscribe(progress -> {
                        if (progressBar != null) {
                            progressBar.setProgress(progress);
                        }
                    });
    }
}

@Override
protected void onDetachedFromWindow() {
    if (autoProgress) {
        autoProgressSubscriber.unsubscribe();
    }
    super.onDetachedFromWindow();
}
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