Android 我能'；t重启应用程序时，在AlarmManager中控制设置时间

我想为自定义时间设置通知，我从

我添加了一些清单代码，用于设备重新启动时使用

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    android:installLocation="internalOnly"
    package="com.example.user.testcounddown">

    <!-- for reboot----------------------  -->
    <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />


    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

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

        <receiver android:name=".AlarmReceiver">
            <intent-filter>
                <action android:name="android.media.action.DISPLAY_NOTIFICATION" />
                <category android:name="android.intent.category.DEFAULT" />
                <!-- for reboot---------------------  -->
                <action android:name="android.intent.action.BOOT_COMPLETED"/>
            </intent-filter>
        </receiver>


    </application>

</manifest>

我的接收器代码：

public class AlarmReceiver extends BroadcastReceiver{
    @Override
    public void onReceive(Context context, Intent intent) {
        Intent notificationIntent = new Intent(context, MainActivity.class);

        TaskStackBuilder stackBuilder = TaskStackBuilder.create(context);
        stackBuilder.addParentStack(MainActivity.class);
        stackBuilder.addNextIntent(notificationIntent);

        PendingIntent pendingIntent = stackBuilder.getPendingIntent(0, PendingIntent.FLAG_UPDATE_CURRENT);

        NotificationCompat.Builder builder = new NotificationCompat.Builder(context);

        Notification notification = builder.setContentTitle("Demo App Notification")
                .setContentText("New Notification From Demo App..")
                .setTicker("New Message Alert!")
                .setSmallIcon(R.mipmap.ic_launcher)
                .setContentIntent(pendingIntent).build();

        NotificationManager notificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
        notificationManager.notify(0, notification);
    }
}

当设备重新启动时，如何让通知在正确的时间显示

cal.add(Calendar.SECOND, 300);

---

任何帮助都将不胜感激，谢谢。

我现在找到路了。我现在找到路了。

cal.add(Calendar.SECOND, 300);