正如您所提到的,我们将安排警报在未来的特定时间执行方法。
我们将有两个班级
- MainAcitvity:在这个类中,我们将安排报警为
在特定时间触发。
- AlarmReciever:报警时
在预定时间触发,该类将收到警报,并且
执行一个方法。
AlarmReciever 类扩展了 BroadcastReceiver 并覆盖了 onRecieve() 方法。在 onReceive() 中,您可以根据需要启动一个活动或服务,例如您可以启动一个活动来振动手机或让手机响铃
需要权限
我们需要在应用程序中使用 AlarmManger 的权限,所以不要忘记在清单文件中声明权限
AndroidManifest 文件
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.test.src"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk android:minSdkVersion="8"
android:targetSdkVersion="17" />
<!-- permission required to use Alarm Manager -->
<uses-permission android:name="com.android.alarm.permission.SET_ALARM"/>
<application
android:icon="@drawable/ic_launcher"
android:label="Demo App" >
<activity
android:name=".MainActivity"
android:label="Demo App" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<!-- Register the Alarm Receiver -->
<receiver android:name=".AlarmReciever"/>
</application>
</manifest>
main.xml
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
android:gravity="center_vertical"
xmlns:android="http://schemas.android.com/apk/res/android">
<TextView
android:id="@+id/textView1"
android:gravity="center_horizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Alarm Manager Example"
android:textAppearance="?android:attr/textAppearanceLarge" />
<Button
android:id="@+id/button1"
android:layout_marginTop="25dp"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Schedule The Alarm"
android:onClick="scheduleAlarm"/>
</LinearLayout>
MainActivity.java
public class MainActivity extends Activity
{
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
public void scheduleAlarm(View V)
{
// time at which alarm will be scheduled here alarm is scheduled at 1 day from current time,
// we fetch the current time in milliseconds and added 1 day time
// i.e. 24*60*60*1000= 86,400,000 milliseconds in a day
Long time = new GregorianCalendar().getTimeInMillis()+24*60*60*1000;
// create an Intent and set the class which will execute when Alarm triggers, here we have
// given AlarmReciever in the Intent, the onRecieve() method of this class will execute when
// alarm triggers and
//we call the method inside onRecieve() method of Alarmreciever class
Intent intentAlarm = new Intent(this, AlarmReciever.class);
// create the object
AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
//set the alarm for particular time
alarmManager.set(AlarmManager.RTC_WAKEUP,time, PendingIntent.getBroadcast(this,1, intentAlarm, PendingIntent.FLAG_UPDATE_CURRENT));
Toast.makeText(this, "Alarm Scheduled for Tommrrow", Toast.LENGTH_LONG).show();
}
}
AlarmReciever.java
public class AlarmReciever extends BroadcastReceiver
{
@Override
public void onReceive(Context context, Intent intent)
{
//call the method here
}
}