Android Code Beispiel:
Mit diesem Code-Beispiel werden in einer Android App ein
Alarm erstellt wie bei einem Wecker und dieser öffnet beim Auslösen des Alarms
eine Activity Seite
MainActivity.java
package com.example.demowakeupactivity;
import androidx.appcompat.app.AppCompatActivity;
import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
public class MainActivity extends AppCompatActivity {
//------------<
MainActivity >------------
private AlarmManager alarmManager = null;
private PendingIntent pendingIntent = null;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
//========< Buttons >===========
public void btnOpenWakeup(View view) {
Intent openWakeup = new Intent(this, WakeupAlarmActivity.class);
startActivity(openWakeup);
}
public void btnAlarmSetWakeup(View view) {
//--------<
btnAlarmSetWakeup() >--------
setupAlarm();
//--------</
btnAlarmSetWakeup() >--------
}
//========</
Buttons >===========
//========< Methods
>===========
private void setupAlarm() {
//--------<
setupAlarm() >--------
// AlarmManager instance from
the system services
alarmManager = (AlarmManager) this.getSystemService(Context.ALARM_SERVICE);
// Intent: this is
responsible to prepare the android component what PendingIntent will start
when the alarm is triggered. That component can be anyone (activity, service,
broadcastReceiver, etc)
// Intent to start the
Broadcast Receiver
Intent intent =new Intent(this, AlarmReceiver.class);
// PendingIntent:
this is the pending intent, which waits until the right time, to be called by
AlarmManager
// The Pending Intent to pass
in AlarmManager
pendingIntent = PendingIntent.getBroadcast(this, 0, intent, 0);
//< create Alarm
>
setAlarm();
//</ create Alarm
>
//--------</ setupAlarm()
>--------
}
private void setAlarm() {
//--------<
setup() >--------
AlarmManager am = (AlarmManager) this.getSystemService(Context.ALARM_SERVICE);
am.set(AlarmManager.RTC_WAKEUP, System.currentTimeMillis()+
2000, pendingIntent);
//--------</
setup() >--------
}
//========</
Methods >===========
//------------</ MainActivity
>------------
}
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AlarmReceiver.java
package com.example.demowakeupactivity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
public class AlarmReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
//------<
onReceive() >--------
//this event triggers when
alarm in Android happens
//*open Wakeup Alarm Activity
Intent alarmIntent = new Intent(context, WakeupAlarmActivity.class);
alarmIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
//open Activitiy
context.startActivity(alarmIntent);
//------</
onReceive() >--------
}
}
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AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.demowakeupactivity">
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/Theme.DemoWakeupActivity">
<receiver android:name=".AlarmReceiver"></receiver>
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN"
/>
<category android:name="android.intent.category.LAUNCHER"
/>
</intent-filter>
</activity>
<activity
android:name=".WakeupAlarmActivity"
android:parentActivityName=".MainActivity"
/>
</application>
</manifest>
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Activities
sind standard.
Activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity"
android:orientation="vertical"
>
<Button
android:id="@+id/btnOpenWakeup"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:backgroundTint="#A1A0A0"
android:onClick="btnOpenWakeup"
android:text="Open
Wakeup" />
<Button
android:id="@+id/btnWakeup"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:backgroundTint="#FFEB3B"
android:onClick="btnAlarmSetWakeup"
android:text="Alarm:
Wakeup"
android:textColor="#F44336"
/>
</LinearLayout>
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Und eine
Alarm Activity
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#FF0000"
tools:context=".WakeupAlarmActivity">
<TextView
android:id="@+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Alarm"
android:textColor="#FFEB3B"
android:textSize="36sp"
android:textStyle="bold"
tools:layout_editor_absoluteX="155dp"
tools:layout_editor_absoluteY="292dp" />
</androidx.constraintlayout.widget.ConstraintLayout>
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