鬧鐘在生活中最常見瞭,在Android中可以通過AlarmManager來實現鬧鐘,AlarmManager類專門用來設置在某個指定的時間去完成指定的時間。AlarmManager就會通過onReceive()方法去執行這些事件,就算系統處於待機狀態,同樣不會影響運行。可以通過Context.getSystemService方法來獲得該服務。AlarmManager中的方法不少,如下:
方法 | 說明 |
Cancel | 取消AlarmManager服務 |
Set | 設置AlarmManager服務 |
setInexactRepeating | 設置不精確周期 |
SetRepeating | 設置精確周期 |
setTimeZone | 設置時區 |
要實現鬧鐘,首先需要創建一個繼承自BroadcastReceiver的類,實現onReceive方法來接受這個Alarm服務,然後通過建立Intent和PendingIntent連接來調用Alarm組件。通過TimerPickerDialog來設置鬧鈴時間,當時間到瞭我們指定的時間後onReceiver方法接受到Alarm服務後的界面。
首先實現接受Alarm服務的AlarmReceiver類,用Toast類提示用戶
[java] public class AlarmReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context arg0, Intent arg1) {
// TODO Auto-generated method stub
Toast.makeText(arg0, "你設置的鬧鈴時間到瞭", Toast.LENGTH_LONG).show();
}
}
public class AlarmReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context arg0, Intent arg1) {
// TODO Auto-generated method stub
Toast.makeText(arg0, "你設置的鬧鈴時間到瞭", Toast.LENGTH_LONG).show();
}
}
由於使用瞭BroadcastReceiver服務,因此需要再AndroidManifest.xml中進行聲明:
[java] <receiver
android:name=".AlarmReceiver"
android:process=":remote">
</receiver>
然後需要設置鬧鈴和取消鬧鈴的實踐進行監聽:
package cn.edu.pku;
import java.util.Calendar;
import android.app.Activity;
import android.app.AlarmManager;
import android.app.PendingIntent;
import android.app.TimePickerDialog;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.TimePicker;
public class AlarmActivity extends Activity {
/** Called when the activity is first created. */
Button mButton1;
Button mButton2;
TextView mTextView;
Calendar calendar;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
calendar=Calendar.getInstance();
mTextView=(TextView)findViewById(R.id.TextView01);
mButton1=(Button)findViewById(R.id.Button01);
mButton2=(Button)findViewById(R.id.Button02);
mButton1.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
calendar.setTimeInMillis(System.currentTimeMillis());
int hour = calendar.get(Calendar.HOUR_OF_DAY);
int minute = calendar.get(Calendar.MINUTE);
new TimePickerDialog(AlarmActivity.this, new TimePickerDialog.OnTimeSetListener() {
public void onTimeSet(TimePicker view, int hourOfDay, int minute) {
// TODO Auto-generated method stub
calendar.setTimeInMillis(System.currentTimeMillis());
calendar.set(Calendar.HOUR_OF_DAY, hourOfDay);
calendar.set(Calendar.MINUTE, minute);
calendar.set(Calendar.SECOND, 0);
calendar.set(Calendar.MILLISECOND, 0);
Intent intent = new Intent(AlarmActivity.this, AlarmReceiver.class);
PendingIntent pendingIntent = PendingIntent.getBroadcast(AlarmActivity.this, 0, intent, 0);
AlarmManager alarmManager = (AlarmManager)getSystemService(ALARM_SERVICE);
alarmManager.set(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), pendingIntent);
alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis() + (10 * 1000),
(24 * 60 * 60 * 1000), pendingIntent);
String tmps = "設置鬧鐘時間為" + format(hourOfDay) + ":" +format(minute);
mTextView.setText(tmps);
}
}, hour, minute, true).show();
}
});
mButton2.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
Intent intent = new Intent(AlarmActivity.this, AlarmReceiver.class);
PendingIntent pendingIntent = PendingIntent.getBroadcast(AlarmActivity.this, 0, intent, 0);
AlarmManager alarmManager = (AlarmManager)getSystemService(ALARM_SERVICE);
alarmManager.cancel(pendingIntent);
mTextView.setText("鬧鈴已取消!");
}
});
}
private String format(int time){
String str = "" + time;
if(str.length() == 1){
str = "0" + str;
}
return str;
}
}
<receiver
android:name=".AlarmReceiver"
android:process=":remote">
</receiver>
然後需要設置鬧鈴和取消鬧鈴的實踐進行監聽:
package cn.edu.pku;
import java.util.Calendar;
import android.app.Activity;
import android.app.AlarmManager;
import android.app.PendingIntent;
import android.app.TimePickerDialog;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.TimePicker;
public class AlarmActivity extends Activity {
/** Called when the activity is first created. */
Button mButton1;
Button mButton2;
TextView mTextView;
Calendar calendar;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
calendar=Calendar.getInstance();
mTextView=(TextView)findViewById(R.id.TextView01);
mButton1=(Button)findViewById(R.id.Button01);
mButton2=(Button)findViewById(R.id.Button02);
mButton1.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
calendar.setTimeInMillis(System.currentTimeMillis());
int hour = calendar.get(Calendar.HOUR_OF_DAY);
int minute = calendar.get(Calendar.MINUTE);
new TimePickerDialog(AlarmActivity.this, new TimePickerDialog.OnTimeSetListener() {
public void onTimeSet(TimePicker view, int hourOfDay, int minute) {
// TODO Auto-generated method stub
calendar.setTimeInMillis(System.currentTimeMillis());
calendar.set(Calendar.HOUR_OF_DAY, hourOfDay);
calendar.set(Calendar.MINUTE, minute);
calendar.set(Calendar.SECOND, 0);
calendar.set(Calendar.MILLISECOND, 0);
Intent intent = new Intent(AlarmActivity.this, AlarmReceiver.class);
PendingIntent pendingIntent = PendingIntent.getBroadcast(AlarmActivity.this, 0, intent, 0);
AlarmManager alarmManager = (AlarmManager)getSystemService(ALARM_SERVICE);
alarmManager.set(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), pendingIntent);
alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis() + (10 * 1000),
(24 * 60 * 60 * 1000), pendingIntent);
String tmps = "設置鬧鐘時間為" + format(hourOfDay) + ":" +format(minute);
mTextView.setText(tmps);
}
}, hour, minute, true).show();
}
});
mButton2.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
Intent intent = new Intent(AlarmActivity.this, AlarmReceiver.class);
PendingIntent pendingIntent = PendingIntent.getBroadcast(AlarmActivity.this, 0, intent, 0);
AlarmManager alarmManager = (AlarmManager)getSystemService(ALARM_SERVICE);
alarmManager.cancel(pendingIntent);
mTextView.setText("鬧鈴已取消!");
}
});
}
private String format(int time){
String str = "" + time;
if(str.length() == 1){
str = "0" + str;
}
return str;
}
}
效果如下:
設置鬧鈴
現在時間到設置鬧鈴的時間:
取消鬧鈴:
摘自 北京大學-Google Android實驗室