在我的应用程序中，有一个 MainActivity 和一个 AlarmActivity。 MainActivity 用于设置闹钟。 AlarmActivity 用于显示警报。在中间，我有一个实现 BroadcastReceiver 的类，用于接收在 MainActivity 中安排的未决 Intent 。我遇到的问题有两个方面。
1) MainActivity 正在创建，而我只希望从下面看到的 onReceive 方法创建 AlarmActivity。
2) 当 AlarmActivity 确实被创建时，它会立即被销毁。请在下面查看我的日志。
请注意，这只会在我关闭屏幕时发生。如果我销毁 MainActivity 并保持屏幕打开直到闹钟响起，一切都很好。如果我让 MainActivity Activity ，并保持屏幕打开，AlarmActivity 会按预期显示在 MainActivity 之上。否则，如果屏幕关闭... AlarmActivity 显示一瞬间，然后消失，我在屏幕上看到 MainActivity。给了什么？
这是我安排闹钟的地方。并不是说 callingContext 变量是我的 MainActivity 类的上下文。
Intent intentAlarm = new Intent(this.callingContext, AlarmActivity.class);
//Get the Alarm Service
AlarmManager alarmManager = (AlarmManager) callingContext.getSystemService(Context.ALARM_SERVICE);
//user our intent and give it a time to broadcast at
alarmManager.set(AlarmManager.RTC_WAKEUP,alarmTime, PendingIntent.getBroadcast(this.callingContext, 1, intentAlarm, PendingIntent.FLAG_CANCEL_CURRENT));
public class AlarmReceiver extends BroadcastReceiver {
final String TAG=this.toString();
@Override
public void onReceive(Context arg0, Intent arg1) {
Log.i(TAG,"onReceive");
//start a new activity, an alarm has gone off
//See that I've tried using the application context, but this did not help.
//Context context=arg0.getApplicationContext();
Intent intent=new Intent(arg0,AlarmActivity.class);
//This flag is required for starting an activity outside of an activity.
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
intent.putExtra("ACTIVITY_STARTED_FROM_BROADCAST_RECEIVER",true);
arg0.startActivity(intent);
}
}
警报 Activity 生命周期方法。
protected void onCreate(Bundle savedInstanceState) {
Log.i(TAG,"onCreate");
if(savedInstanceState==null) {
super.onCreate(savedInstanceState);
setContentView(R.layout.layout_alarm);
}
}
public static void acquireScreenCpuWakeLock(Context context) {
if (sCpuWakeLock != null) {
return;
}
PowerManager pm = (PowerManager) context.getSystemService(Context.POWER_SERVICE);
sCpuWakeLock = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK
| PowerManager.ACQUIRE_CAUSES_WAKEUP | PowerManager.ON_AFTER_RELEASE, "TYLER");
sCpuWakeLock.acquire();
}
public static void releaseCpuLock() {
if (sCpuWakeLock != null) {
sCpuWakeLock.release();
sCpuWakeLock = null;
}
}
@Override
protected void onResume() {
Log.i(TAG,"onResume");
super.onResume();
// getFragmentManager().beginTransaction().add(R.id.alarm_frame, new AlarmFragment()).commit();
}
@Override
protected void onStart() {
Log.i(TAG,"onStart");
super.onStart();
final Window win = getWindow();
win.addFlags(WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED |
WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD |
WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON |
WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON |
WindowManager.LayoutParams.FLAG_ALLOW_LOCK_WHILE_SCREEN_ON);
acquireScreenCpuWakeLock(this);
alarmFragment=new AlarmFragment();
alarmFragment.setArguments(getIntent().getExtras());
getFragmentManager().beginTransaction().add(R.id.alarm_frame, alarmFragment).commit();
}
@Override
protected void onPause(){
Log.i(TAG,"onPause");
super.onPause();
releaseCpuLock();
getFragmentManager().beginTransaction().remove(alarmFragment);
Log.d("pfaff","wakelock released, alarm activity paused");
}
@Override
protected void onDestroy(){
Log.i(TAG,"onDestroy");
super.onDestroy();
// wakeLock.release();
Log.d("pfaff","alarm activity destroyed");
}
}
报警 Framgnet 生命周期方法。
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// TODO Auto-generated method stub
return inflater.inflate(R.layout.fragment_alarm, container, false);
}
@Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
}
@Override
public void onAttach(Activity activity){
Log.i(TAG,"onAttach");
super.onAttach(activity);
this.activity=activity;//camera
}
@Override
public void onStart() {
Log.i(TAG, "onStart");
super.onStart();
}
@Override
public void onResume() {
Log.i(TAG,"onResume");
super.onResume();
final AlarmFragment thisFragment = this;
}
@Override
public void onPause() {
Log.i(this.toString(),"onPause");
super.onPause();
getActivity().onBackPressed();
}
@Override
public void onDestroy() {
// TODO Auto-generated method stub
Log.i(this.toString(),"onDestroy");
super.onDestroy();
// tearDownMedia();
scanMyMedia();
releaseCameraAndPreview();
if(timeReceiverIsRegistered) {
getActivity().unregisterReceiver(_broadcastReceiver);
}
}
这是日志:
11-27 21:56:46.036 29370-29370/com.example.videoalarmt I/com.example.videoalarmt.AlarmReceiver@41eb2158﹕ onReceive
11-27 21:56:46.066 29370-29370/com.example.videoalarmt I/com.example.videoalarmt.MainActivity@41eaaf08﹕ onCreate
11-27 21:56:46.066 29370-29370/com.example.videoalarmt I/timePickerFragment{41ea1e58}﹕ onCreateView
11-27 21:56:46.096 29370-29370/com.example.videoalarmt E/TextView﹕ Saved cursor position 2/2 out of range for (restored) text
11-27 21:56:46.096 29370-29370/com.example.videoalarmt E/TextView﹕ Saved cursor position 2/2 out of range for (restored) text
11-27 21:56:46.136 29370-29370/com.example.videoalarmt I/com.example.videoalarmt.AlarmActivity@41ed7bf8﹕ onCreate
11-27 21:56:46.136 29370-29370/com.example.videoalarmt I/com.example.videoalarmt.AlarmActivity@41ed7bf8﹕ onStart
11-27 21:56:46.136 29370-29370/com.example.videoalarmt I/com.example.videoalarmt.AlarmActivity@41ed7bf8﹕ onResume
11-27 21:56:46.136 29370-29370/com.example.videoalarmt I/AlarmFragment{41edaa40}﹕ onAttach
11-27 21:56:46.136 29370-29370/com.example.videoalarmt I/AlarmFragment{41edaa40}﹕ onViewCreated
11-27 21:56:46.136 29370-29370/com.example.videoalarmt I/AlarmFragment{41edaa40}﹕ onStart
11-27 21:56:46.136 29370-29370/com.example.videoalarmt I/AlarmFragment{41edaa40}﹕ onResume
11-27 21:56:46.136 29370-29370/com.example.videoalarmt I/AlarmFragment{41edaa40}﹕ was started from broadcast receiver
11-27 21:56:46.206 29370-29370/com.example.videoalarmt I/AlarmFragment{41edaa40 #0 id=0x7f0a0024}﹕ onPause
11-27 21:56:46.206 29370-29370/com.example.videoalarmt I/com.example.videoalarmt.AlarmActivity@41ed7bf8﹕ onPause
11-27 21:56:46.787 29370-29370/com.example.videoalarmt I/AlarmFragment{41edaa40 #0 id=0x7f0a0024}﹕ Putting media recorder in PREPARED state from DATASOURCECONFIGURED state
11-27 21:56:46.787 29370-29370/com.example.videoalarmt I/MediaRecorderJNI﹕ prepare: surface=0x76608e58
11-27 21:56:47.137 29370-29370/com.example.videoalarmt E/MediaPlayer﹕ Should have subtitle controller already set
11-27 21:56:47.137 29370-29370/com.example.videoalarmt I/Choreographer﹕ Skipped 53 frames! The application may be doing too much work on its main thread.
11-27 21:56:47.237 29370-29370/com.example.videoalarmt I/com.example.videoalarmt.AlarmActivity@41ed7bf8﹕ onStop
11-27 21:56:47.598 29370-29370/com.example.videoalarmt I/AlarmFragment{41edaa40 #0 id=0x7f0a0024}﹕ onDestroy
11-27 21:56:47.598 29370-29370/com.example.videoalarmt I/com.example.videoalarmt.AlarmActivity@41ed7bf8﹕ onDestroy
11-27 21:56:47.658 29370-29370/com.example.videoalarmt W/IInputConnectionWrapper﹕ showStatusIcon on inactive InputConnection
11-27 21:57:02.243 29370-29370/com.example.videoalarmt I/com.example.videoalarmt.MainActivity@41eaaf08﹕ onDestroy
这是我的 list
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.videoalarmt"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="15"
android:targetSdkVersion="21" />
<uses-permission android:name="com.android.alarm.permission.SET_ALARM"/>
<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.WAKE_LOCK" />
<uses-permission android:name="android.permission.RECORD_AUDIO" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.DISABLE_KEYGUARD" />
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<uses-feature android:name="android.hardware.camera" android:required="true" />
<uses-feature android:name="android.hardware.camera.front" android:required="true" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@android:style/Theme.Holo.Light.NoActionBar"
>
<meta-data android:name="com.google.android.gms.version"
android:value="@integer/google_play_services_version" />
<receiver android:name="com.example.videoalarmt.AlarmReceiver"/>
<activity
android:name="com.example.videoalarmt.MainActivity"
android:label="@string/app_name"
android:screenOrientation="portrait"
>
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="com.example.videoalarmt.AlarmActivity"
android:label="@string/app_name"
android:screenOrientation="portrait"
>
</activity>
<activity android:name="com.google.android.gms.ads.AdActivity"
android:configChanges="keyboard|keyboardHidden|orientation|screenLayout|uiMode|screenSize|smallestScreenSize"/>
</application>
</manifest>
最佳答案
没有理由创建 MainActivity。我在您的代码中发现的唯一问题是在下面一行:
Intent intentAlarm = new Intent(this.callingContext, AlarmActivity.class);
在这里，您正在使用 Activity 类创建一个 Intent ，但在您的未决 Intent 中，您使用的是 getBroadCast() 方法。应该是:
Intent intentAlarm = new Intent(this.callingContext, AlarmReceiver.class);
我没有尝试过您的代码，但这可能是导致您出现问题的原因。 请进行此更改并检查是否仍在创建 Mainactivity？
关于android - 我正在从广播接收器开始一个 Activity ，但为什么我的其他 Activity 也开始了？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/27182871/