onBackPressed和android中的線程

Question

我有一個線程在我的ListActivity中運行，有時需要太長時間才能從互聯網獲取數據，所以用戶可能想要退出並返回。

但是，當我按下BACK按鈕時，它顯示前一個視圖，但線程仍然保持執行狀態。

我重寫onBackPressed()方法，並設置breakpointm但在調試時我看到，它不經過它，所以我不知道還能做什麼？

任何想法？

謝謝

這是我的代碼。基本上，我不知道爲什麼它，即使它可以追溯到以前的活動當y按BACK按鈕不執行onKeyPressed() ... 代碼編輯

 
// package + imports 
public class ListaVideosActivity extends ListActivity implements Runnable { 

    private ProgressDialog pd; 
    private Context mContext; 
    private View header; 
    private View footer; 
    private Vibrator vibrator; 
    private boolean firsTime = true; 

    private Thread thread; 

    private Long playlistId; 
    private String playlistTitle; 
    protected int headerDrawable; 

    private Playlist pList; 

    public static final String TAG_PL_ID = "id_playlist"; 
    public static final String TAG_PL_TITLE = "title_playlist"; 
    public static final String TAG_PL_HEADER = "header_playlist"; 

    private SensorManager mSensorManager; 
    private ShakeListener mShakeListener; 

    /** Called when the activity is first created. */ 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 

     // Context es el MainTabActivity 
     mContext = getParent(); 
     MainTabActivity.tabHost.getTabWidget().setVisibility(View.GONE); 

     playlistId = getIntent().getLongExtra(TAG_PL_ID, 0L); 
     playlistTitle = getIntent().getStringExtra(TAG_PL_TITLE); 
     headerDrawable = getIntent().getIntExtra(TAG_PL_HEADER, 0); 

     setLoadingView(); 

     thread = new Thread(this); 
     thread.start(); 

     createListHeader(); 

     mSensorManager = (SensorManager) getSystemService(SENSOR_SERVICE); 
     mShakeListener = new ShakeListener(mSensorManager); 

    } 

    @Override 
    protected void onPause() { 
     mSensorManager.unregisterListener(mShakeListener); 
     super.onPause(); 
    } 

    @Override 
    protected void onResume() { 
     super.onResume(); 
     mSensorManager.registerListener(mShakeListener, mSensorManager 
       .getDefaultSensor(Sensor.TYPE_ACCELEROMETER), 
       SensorManager.SENSOR_DELAY_GAME); 
    } 

    private void setLoadingView() { 

     LayoutInflater inflater = (LayoutInflater) mContext 
       .getSystemService(LAYOUT_INFLATER_SERVICE); 
     View layout = inflater.inflate(R.layout.videos_loading_dialog, null); 

     MainTabActivity.tabHost.getTabWidget().setVisibility(View.GONE); 

     setContentView(layout); 

    } 

    private void createListHeader() { 
     LayoutInflater inflater = (LayoutInflater) mContext 
       .getSystemService(LAYOUT_INFLATER_SERVICE); 
     header = inflater.inflate(R.layout.videos_list_header, null); 
     footer = inflater.inflate(R.layout.screen_footer, null); 

     ((ImageView) header).setImageResource(headerDrawable); 

    } 

    @Override 
    protected void onListItemClick(ListView l, View v, int position, long id) { 

     Video video = (Video) l.getItemAtPosition(position); 

     Intent intent = new Intent(mContext, BCPlayerActivity.class); 
     BCPlayerActivity.video = video; 
     mContext.startActivity(intent); 

    } 

    public void run() { 

     pList = BCVideoGetter.getPlaylistById(playlistId); 
     if (pList != null) { 
      // hay lista 
      handler.sendEmptyMessage(1); 
     } else { 
      handler.sendEmptyMessage(0); 
     } 

    } 

    private Handler handler = new Handler() { 
     @Override 
     public void handleMessage(Message msg) { 

      switch (msg.what) { 

      case 0: 
       Toast.makeText(mContext, R.string.noHostError, 
         Toast.LENGTH_LONG).show(); 

      case 1: 

       if (firsTime) { 
        // Shake 
        mShakeListener.setForceThreshHold(1.9); 
        mShakeListener 
          .setOnShakeListener(new ShakeListener.OnShakeListener() { 
           @Override 
           public void onShake() { 

            if (pd == null || !pd.isShowing()) { 
             vibrator.vibrate(300); 
             updateVideosList(); 
            } 

           } 
          }); 

        MainTabActivity.tabHost.getTabWidget().setVisibility(
          View.VISIBLE); 

        setContentView(R.layout.videos_list); 

        getListView().addHeaderView(header, null, false); 
        getListView().addFooterView(footer, null, false); 

        setListAdapter(new VideosListAdapter(mContext, 
          R.layout.videos_list_item, (ArrayList) pList 
          .getVideos())); 

        vibrator = ((Vibrator) getSystemService(Context.VIBRATOR_SERVICE)); 
        firsTime = false; 
       } else { 
        ((VideosListAdapter) getListAdapter()).setItems((ArrayList) pList.getVideos()); 
        ((VideosListAdapter) getListAdapter()) 
          .notifyDataSetChanged(); 
       } 

       if (pd != null) 
        pd.dismiss(); 
       break; 
      } 

     } 
    }; 

    @Override 
    public void onBackPressed() { 

     mSensorManager.unregisterListener(mShakeListener); 
     thread.interrupt(); 
     PestanaProgramasTVActivity.group.back(); 

    } 

    public boolean onCreateOptionsMenu(Menu menu) { 

     MenuInflater inflater = getMenuInflater(); 
     inflater.inflate(R.menu.news_list_menu, menu); 

     return true; 

    } 

    @Override 
    public boolean onOptionsItemSelected(MenuItem item) { 
     switch (item.getItemId()) { 
     case R.id.update: 

      updateVideosList(); 

      break; 
     case R.id.settings: 
      Intent settingsActivity = new Intent(mContext, 
        SettingsActivity.class); 
      startActivity(settingsActivity); 
      break; 
     } 
     return true; 
    } 

    private void updateVideosList() { 

     if (pd == null || !pd.isShowing()) { 
      pd = ProgressDialog.show(mContext, "", getResources().getString(
        R.string.news_update), true); 
      thread = new Thread(this); 
      thread.start(); 
     } 

    } 
} 

Answer 1

thread.stop（）是不推薦使用的方法。你可以參考this文檔來看看如何正確地殺死一個線程。

Answer 2

任何想法？

停止線程。 Android不處理你自己分叉的線程。如果你分叉它，你停止它。

正好如何停止線程取決於線程正在做什麼，這是你拒絕在這裏解釋，所以我不能給你具體的建議。