I have an application that plays sound when viewing slides. When I change the slide or the "Home" button I exit the activity, the completion of the media player is done. However, if I exit the slide view with the phone / tablet “Back” hardware button, the MediaPlayer remains to work in the background, which does not correspond to the application logic.
Tell me how to "screw" the stop MediaPlayer to pressing the hardware button "Back"?
public class SliderActivity extends AppCompatActivity implements CompoundButton.OnCheckedChangeListener { static final String TAG = "myLogs"; ViewPager viewPager; CustomSwipeAdapter adapter; ToggleButton toggleButton; ImageButton imageButton; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); requestWindowFeature(Window.FEATURE_NO_TITLE); getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN); getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON); setContentView(R.layout.activity_slider); imageButton = (ImageButton) findViewById(R.id.imageButtonHome); View.OnClickListener clickHome = new View.OnClickListener() { @Override public void onClick(View v) { if(mp !=null && mp.isPlaying()){ mp.stop(); } GoHome(); } }; imageButton.setOnClickListener(clickHome); /* * Читаем json и создаем из него объект книги bookFiles */ Gson gson = new Gson(); int bookId = GetBookId(); String fileName = "book_" + bookId + ".json"; String gsResult = MyJSON.getData(getApplicationContext(), fileName); BookFiles bookFiles = gson.fromJson(gsResult, BookFiles.class); final String folderB = "bookfiles_" + bookId; /* Получаем из объекта bookFiles массивы путей к файлам книги */ ArrayList<String> pagesFiles = bookFiles.getPagesPath(); final ArrayList<String> soundsFiles = bookFiles.getSoundsPath(); viewPager = (ViewPager) findViewById(R.id.view_pager); viewPager.setPageTransformer(true, new ZoomOutPageTransformer()); adapter = new CustomSwipeAdapter(this, pagesFiles); viewPager.setAdapter(adapter); toggleButton = (ToggleButton) findViewById(R.id.imageButtonPlay); //слушаем номер слайда при перелистывании viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() { Boolean first = true; @Override public void onPageScrolled(final int position, float positionOffset, int positionOffsetPixels) { if (first && positionOffset == 0 && positionOffsetPixels == 0){ onPageSelected(0); first = false; } mp.setOnCompletionListener(new MediaPlayer.OnCompletionListener() { int pagen = position+1; @Override public void onCompletion(MediaPlayer mp) { viewPager.setCurrentItem(pagen, true); } }); } @Override public void onPageSelected(int position) { String nameS = Uri.parse(soundsFiles.get(position)).getLastPathSegment(); if(mp != null){ mp.stop(); } getMedia(nameS, folderB); toggleButton.setOnCheckedChangeListener(SliderActivity.this); if (toggleButton.isChecked()){ mp.start(); } } @Override public void onPageScrollStateChanged(int state) { } }); } public int GetBookId() { Intent intent = getIntent(); int bookId = intent.getIntExtra("bookId", 1); return bookId; } @Override public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) { if (isChecked) mp.start(); else if (mp.isPlaying()) { mp.pause(); } } public void getMedia(String nameS, String folderB) { try { final String soundPath = String.valueOf(getApplicationContext().getExternalFilesDir(folderB)); final Uri souF = Uri.fromFile(new File(soundPath, nameS)); final MediaPlayer mp = MyPlayer.getMp(getApplicationContext(), souF); mp.setAudioStreamType(AudioManager.STREAM_MUSIC); } catch (Exception e) { e.printStackTrace(); } } private void GoHome() { new Handler().postDelayed(new Runnable() { @Override public void run() { Intent intent = new Intent(SliderActivity.this, MainActivity.class); startActivity(intent); finish(); } }, 10); } } 
