Question

我已经设置了一个首选项屏幕，其中我有一个列表首选项，允许用户选择时间间隔来通知他们。

他们可以选择是否每隔2,4,8,10或12小时通知他们。

以下是我的列表首选项：

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android" >
<ListPreference
            android:title="Notification Timer"
            android:summary="Select when to Notify"
            android:dialogTitle="Show Notification after every:"
            android:positiveButtonText="OK"
            android:negativeButtonText="Cancel"
            android:entries="@array/entries"
            android:entryValues="@array/entries"
            android:key="listPrefs" />
</PreferenceScreen>

这是我的Settings.class文件：

public class Settings extends PreferenceActivity implements OnPreferenceChangeListener{

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        addPreferencesFromResource(R.xml.settings);

        ListPreference listPreference = (ListPreference) findPreference("listPrefs");
        listPreference.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {

            @Override
            public boolean onPreferenceChange(Preference preference, Object newValue) {

                return false;
            }
        });
        @Override
    public boolean onPreferenceChange(Preference preference, Object newValue) {
        // TODO Auto-generated method stub
        return false;
    }
}

我希望每当用户更改通知他/她的时间间隔时更新或重置警报。例如 - 如果用户选择4小时而不是他/她必须在4小时后得到通知，或者如果用户选择10小时，则他/她必须在10小时后得到通知！

Answer 1

请按照以下步骤操作：

将以下方法复制到 Setting.java 文件中：

private final int NOTIFICATION_TIMER = 11;

public void setAlarm(Context mContext,int requestCode,long time) {

    Intent myIntent = new Intent(mContext, AlarmReceiver.class);
    PendingIntent pendingIntent = PendingIntent.getBroadcast(mContext, requestCode, myIntent,0);

    cancelAlarmIfExists(mContext,requestCode,myIntent);

    AlarmManager alarmManager = (AlarmManager)mContext.getSystemService(ALARM_SERVICE);
    alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, (System.currentTimeMillis()+time), time, pendingIntent);
}

public void cancelAlarmIfExists(Context mContext,int requestCode,Intent intent){
    try {
        PendingIntent pendingIntent = PendingIntent.getBroadcast(mContext, requestCode, intent,0);
        AlarmManager am=(AlarmManager)mContext.getSystemService(Context.ALARM_SERVICE);
        am.cancel(pendingIntent);
    } catch (Exception e) {
        e.printStackTrace();
    }
}

从onPreferenceChange()方法调用它们。像这样：

listPreference.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
    @Override
    public boolean onPreferenceChange(Preference preference, Object newValue) {

        long time = 34352355253; // calculate millisecons from change value by user.
        setAlarm(Settings.this,NOTIFICATION_TIMER,time);
        return false;
    }
});

Answer 2

FLAG_CANCEL_CURRENT与上述答案具有相同的效果

PendingIntent pi = PendingIntent.getService(this, 0, notifIntent, PendingIntent.FLAG_CANCEL_CURRENT);

如何编辑/重置Alarm Manager？

2 个答案: