我有两个活动,mainActivityCaller和mainActivity,其中activity mainActivityCaller通过startActivity()方法启动activity mainActivity。
在通知中,如果活动mainActivity已暂停但存在于任务堆栈中(使用下面的代码完成),我将启动它;如果没有,我将启动mainActivityCaller(即,如果mainActivity实例已被用户或系统销毁)。
当用户的位置改变时,mainActivity广播以下内容
@Override
public void onLocationChanged(Location location) {
final Location finalLocation = location;
final Intent restartMainActivity = new Intent(this, MainActivity.class);
sendOrderedBroadcast(
new Intent(LOCATION_CHANGED_ACTION),
null,
new BroadcastReceiver() {
@TargetApi(16)
@Override
public void onReceive(Context context, Intent intent) {
if (getResultCode() != RESULT_OK) {
PendingIntent pi = PendingIntent.getActivity(context, 0, restartMainActivity, 0);
Notification.Builder nb = new Notification.Builder(context)
.setAutoCancel(true)
.setContentText("Lat = " + Double.toString(finalLocation.getLatitude()) + "\nLong = " + Double.toString(finalLocation.getLongitude()))
.setContentIntent(pi)
.setSmallIcon(android.R.drawable.stat_sys_warning));
NotificationManager nm = (NotificationManager) context.getSystemService(NOTIFICATION_SERVICE);
nm.notify(0, nb.build());
}
}
},
null,
0,
null,
null);
}
mainActivity的oncreate方法中还实例化了一个广播接收器(下面是缩写版本)
@Override
protected void onCreate(Bundle savedInstanceState) {
mReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
if (isOrderedBroadcast())
setResultCode(RESULT_OK);
}
};
}
在onresume方法中注册接收者
@Override
protected void onResume() {
super.onResume();
IntentFilter intentFilter = new IntentFilter(LOCATION_CHANGED_ACTION);
registerReceiver(mReceiver, intentFilter);
}
并在onpause方法中注销
@Override
protected void onPause() {
super.onPause();
if (mReceiver != null) {
unregisterReceiver(mReceiver);
}
}
在清单文件中,mainActivity被声明为只能在一个任务中启动
<activity android:name=".MainActivity"
android:launchMode="singleTask" />
现在,这将创建或重新启动mainactivity(取决于mainactivity是否被销毁或停止)。在任何任务后堆栈中都不存在mainActivity实例时,如何修改此设置以启动mainActivityCaller?
谢谢!
最佳答案
你要在AndroidManifest.xml注册你的广播接收器,让接收者成为一个公共Java类,并让接收者重新启动活动。
在androidmanifest.xml中:
<receiver
android:name=".RestarteActivityBR"
android:exported="false">
<intent-filter>
<action android:name="com.example.intent.restart" />
</intent-filter>
</receiver>
在restartactivitybr.java中:
public class RestartActivityBR extends BroadcastReceiver
{
@Override
public void onReceive(final Context context, final Intent intent)
{
Intent main = new Intent(context, AppMain.class);
main.addFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT | Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(main);
}
}