onBackPressed和android中的线程
我有一个线程运行在我的ListActivity ，有时需要很长时间才能从互联网获取数据，所以用户可能想退出并返回。
但是，当我按BACK按钮时，它显示前一个视图，但线程仍然保持执行状态。
我重写了onBackPressed()方法并设置了一个breakfront，但在调试时，我发现它没有经过它，所以我不知道还有什么要做。
任何想法？ 谢谢！
这是我的代码。 基本上，我不知道为什么它不执行onKeyPressed()即使当我们按下BACK按钮时它会回到上一个活动。
代码编辑
// package + imports
public class ListaVideosActivity extends ListActivity implements Runnable {
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";
protected int headerDrawable;
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;
private Playlist pList;
private SensorManager mSensorManager;
private ShakeListener mShakeListener;
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<Video>) pList
.getVideos()));
vibrator = ((Vibrator) getSystemService(Context.VIBRATOR_SERVICE));
firsTime = false;
} else {
((VideosListAdapter) getListAdapter()).setItems((ArrayList<Video>) pList.getVideos());
((VideosListAdapter) getListAdapter())
.notifyDataSetChanged();
}
if (pd != null)
pd.dismiss();
break;
}
}
};
/**
* 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);
}
}
@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();
}
}
}
thread.stop（）是不推荐使用的方法。 你可以参考这个文档来看看如何正确地杀死一个线程。
任何想法？
停止线程。 Android不处理你自己分叉的线程。 如果你分叉它，你停止它。
究竟如何阻止线程取决于线程在做什么，你拒绝在这里解释，所以我不能给你具体的建议。
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