我有一个名为MyTabActivity的TabActivity,其中包含多个选项卡,我使用以下代码创建这些选项卡:
public class MyTabActivity extends TabActivity {
public void onCreate(Bundle savedInstanceState) {
setContentView(R.layout.my_tabs);
tabHost = (TabHost)findViewById(android.R.id.tabhost);
tabHost.getTabWidget().setDividerDrawable(R.drawable.tab_divider);
Intent intent = new Intent().setClass(this, MyTab1.class);
setupTab(new TextView(this), "Tab1", intent);
intent = new Intent().setClass(this, MyTab2.class);
setupTab(new TextView(this), "Tab2", intent);
intent = new Intent().setClass(this, MyTab3.class);
setupTab(new TextView(this), "Tab3", intent);
}
private void setupTab(final View view, final String tag, Intent intent) {
View tabview = createTabView(tabHost.getContext(), tag);
TabHost.TabSpec setContent = tabHost.newTabSpec(tag).setIndicator(tabview).setContent(intent);
tabHost.addTab(setContent);
}
private static View createTabView(final Context context, final String text) {
View view = LayoutInflater.from(context).inflate(R.layout.tabs_bg, null);
TextView tv = (TextView) view.findViewById(R.id.tabsText);
tv.setText(text);
return view;
}
}
在一个标签页(MyTab2)上的一个活动注册了一个广播接收器,这样在特定事件发生时,该标签页将刷新其显示的数据。我没有在onPause中注销BroadcastReceiver,因为我希望即使它当前不在前面,该活动也能自我刷新。
public class MyTab2 extends Activity {
// listener to receive broadcasts from activities that change
// data that this activity needs to refresh on the view
protected class MyListener extends BroadcastReceiver {
public void onReceive(Context context, Intent intent) {
if (intent.getAction().equals("myapp.REFLECT__CHANGES")) {
//request new data from the server
refreshData();
}
}
}
protected void onResume() {
// if listener is not registered yet, register it
// normally we would unregister the listener onPause, but we want
// the listener to fire even if the activity is not in front
if (!listenerIsRegistered) {
registerReceiver(listener, new IntentFilter("myapp.REFLECT_CHANGES"));
listenerIsRegistered = true;
}
super.onResume();
}
我的问题是,即使我回退到显示MyTabActivity之前的活动并第二次启动MyTabActivity,似乎在第一次进入MyTabActivity时创建的MyTab2实例仍然存在,并且当我广播触发选项卡刷新其数据时,旧的MyTab2实例和新的MyTab2实例都会刷新,我的问题是如何在回退TabActivity时杀死所有子活动?
旧的子活动实例是否仍然存在是因为我没有在活动离开前注销BroadcastReceiver吗?
正如你所想象的那样,每次启动后续的MyTabActivity时,这个问题就会变得更加复杂。