在锁定屏幕上显示通知

Question

我成功设置了 GCM 通知，并且可以通过 GCM 从服务器端成功获取消息。

我还可以通过这些代码在 android 的通知栏系统上显示通知。

我尝试使用这些方式在锁定屏幕上显示通知，但没有奏效：

1 - 添加<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />权限

2 - 添加android:showOnLockScreen="true"在 manifest.xml 中定义的主要活动

3 - 在 java 文件中添加到主活动中： getWindow().addFlags(WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD | WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED | WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON | WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);

4 -Show notifications已在应用程序设置系统中选中复选框。

知道如何在锁定屏幕上显示通知的人，

请帮助我，我做了很多搜索但没有帮助。

谢谢，

p/s :

我正在使用三星 S3、Android 4.3 进行测试。已启用锁定屏幕页面。

我从Intent Service.

代码显示通知：

// Put the message into a notification and post it.
// This is just one simple example of what you might choose to do with
// a GCM message.
private void sendNotification(String msg) {
    mNotificationManager = (NotificationManager)
            this.getSystemService(Context.NOTIFICATION_SERVICE);

    PendingIntent contentIntent = PendingIntent.getActivity(this, 0,
            new Intent(this, Pas.class)
                    .addFlags(Intent.FLAG_ACTIVITY_NEW_TASK
                            | Intent.FLAG_ACTIVITY_CLEAR_TASK),
            PendingIntent.FLAG_CANCEL_CURRENT);
    NotificationCompat.Builder mBuilder =
            new NotificationCompat.Builder(this)
                    .setSmallIcon(R.drawable.ic_play_dark)
                    .setContentTitle("");
    // Set Big View style to see full content of the message
    NotificationCompat.BigTextStyle inboxStyle =
            new NotificationCompat.BigTextStyle();

    inboxStyle.setBuilder(mBuilder);
    inboxStyle.bigText("");
    inboxStyle.setBigContentTitle("");
    inboxStyle.setSummaryText("");

    // Moves the big view style object into the notification object.
    mBuilder.setStyle(inboxStyle);
    mBuilder.setContentText(msg);
    mBuilder.setDefaults(Notification.DEFAULT_ALL);
    mBuilder.setContentIntent(contentIntent);

    mNotificationManager.notify(NOTIFICATION_ID, mBuilder.build());
}

我使用这些权限：

<uses-permission android:name="android.permission.ACCESS_WIFI_STATE"></uses-permission>
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE"></uses-permission>

<uses-permission android:name="android.permission.BLUETOOTH"/>
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.WAKE_LOCK" />

<uses-permission android:name="android.permission.CAPTURE_AUDIO_OUTPUT" />
<uses-permission android:name="android.permission.MEDIA_CONTENT_CONTROL" />
<uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS" />

<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />

<uses-permission android:name="com.google.android.c2dm.permission.RECEIVE" />
<uses-permission android:name="com.trek2000.android.pas.permission.C2D_MESSAGE" />

<permission
    android:name="com.trek2000.android.pas.permission.C2D_MESSAGE"
    android:protectionLevel="signature" />

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >

    <activity
        android:name="com.android.pas.Pas"
        android:showOnLockScreen="true"
        android:label="@string/app_name" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>

    <!-- Receiver GCM -->
    <receiver
        android:name = "receiver.GcmBroadcastReceiver"
        android:permission = "com.google.android.c2dm.permission.SEND">
        <intent-filter>
            <action android:name = "com.google.android.c2dm.intent.RECEIVE" />

            <category android:name = "com.trek2000.android.pas" />
        </intent-filter>
    </receiver>

    <!-- Services -->
    <service
        android:name = "service.GcmIntentService"
        android:exported = "true" />

</application>

Answer 1

I managed to get notification shown in lock screen this way.

Here is the complete code with comments.

// Logic to turn on the screen
PowerManager powerManager = (PowerManager) context.getSystemService(POWER_SERVICE);

if (!powerManager.isInteractive()){ // if screen is not already on, turn it on (get wake_lock for 10 seconds)
    PowerManager.WakeLock wl = powerManager.newWakeLock(PowerManager.FULL_WAKE_LOCK |PowerManager.ACQUIRE_CAUSES_WAKEUP |PowerManager.ON_AFTER_RELEASE,"MH24_SCREENLOCK");
    wl.acquire(10000);
    PowerManager.WakeLock wl_cpu = powerManager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK,"MH24_SCREENLOCK");
    wl_cpu.acquire(10000);
}

// Notification stuff

NotificationCompat.Builder builder = new NotificationCompat.Builder(context.getApplicationContext());
builder.setSmallIcon(R.drawable.attendance_icon);
builder.setContentTitle("Attendance not marked");
builder.setContentText("Attendance is not marked for today. Please mark the same.");

TaskStackBuilder taskStackBuilder = TaskStackBuilder.create(context.getApplicationContext());
Intent intent = new Intent(context.getApplicationContext(), ActivityNewRecord.class);
taskStackBuilder.addParentStack(ActivityNewRecord.class);
taskStackBuilder.addNextIntent(intent);

PendingIntent pendingIntent = taskStackBuilder.getPendingIntent(100, PendingIntent.FLAG_UPDATE_CURRENT);
builder.setContentIntent(pendingIntent);
final long[] DEFAULT_VIBRATE_PATTERN = {0, 250, 250, 250};
builder.setVibrate(DEFAULT_VIBRATE_PATTERN);
builder.setLights(Color.WHITE, 2000, 3000);
builder.setSound(Settings.System.DEFAULT_NOTIFICATION_URI);

// This is the answer to OP's question, set the visibility of notification to public.
builder.setVisibility(NotificationCompat.VISIBILITY_PUBLIC); 


NotificationManager notificationManager = (NotificationManager) context.getSystemService(NOTIFICATION_SERVICE);
notificationManager.notify(100, builder.build());

However, showing notification on lock screen might not work for some device. (I tested on on Nexus phones and it works, but didn't work on Xiaomi device)

But then again, once the notification is received, screen will light up, vibrate, and ring.