WorkManager 是一个用于将工作排队的库，保证在满足其约束后执行。
因此，在浏览了 Constraints 类之后，我还没有找到任何可以为工作添加时间限制的函数。例如，我想在早上 8:00 开始执行一项工作（该工作可以是两种类型 OneTimeWorkRequest 或 PeriodicWorkRequest 中的任何一种）。如何添加约束来使用 WorkManager 安排这项工作。
不幸的是，目前您无法在特定时间安排工作。如果您有时间关键的实现，那么您应该使用 AlarmManager 设置在打瞌睡时可以触发的警报，方法是使用 setAndAllowWhileIdle() 或 setExactAndAllowWhileIdle()。
您可以使用
WorkManager创建Worker类：
public class MyWorker extends Worker {
@Override
public Worker.WorkerResult doWork() {
// Do the work here
// Indicate success or failure with your return value:
return WorkerResult.SUCCESS;
// (Returning RETRY tells WorkManager to try this task again
// later; FAILURE says not to try again.)
}
}
然后安排
OneTimeWorkRequestOneTimeWorkRequest mywork=
new OneTimeWorkRequest.Builder(MyWorker.class)
.setInitialDelay(<duration>, <TimeUnit>)// Use this when you want to add initial delay or schedule initial work to `OneTimeWorkRequest` e.g. setInitialDelay(2, TimeUnit.HOURS)
.build();
WorkManager.getInstance().enqueue(mywork);
// Create a Constraints that defines when the task should run
Constraints myConstraints = new Constraints.Builder()
.setRequiresDeviceIdle(true)
.setRequiresCharging(true)
// Many other constraints are available, see the
// Constraints.Builder reference
.build();
然后创建一个使用这些约束的 OneTimeWorkRequest
OneTimeWorkRequest mywork=
new OneTimeWorkRequest.Builder(MyWorker.class)
.setConstraints(myConstraints)
.build();
WorkManager.getInstance().enqueue(mywork);
PeriodicWorkRequest periodicWork = new PeriodicWorkRequest.Builder(MyWorker.class, 12, TimeUnit.HOURS)
.build();
WorkManager.getInstance().enqueue(periodicWork);
这将创建一个PeriodicWorkRequest，每12小时定期运行一次。
PeriodicWorkRequests 现在支持从版本 2.1.0-alpha02 开始的初始延迟。您可以使用PeriodicWorkRequest.Builder 上的setInitialDelay 方法来设置初始延迟。 链接在此
每天上午 8:00 的时间表示例。这里我使用joda时间库进行时间操作。
final int SELF_REMINDER_HOUR = 8;
if (DateTime.now().getHourOfDay() < SELF_REMINDER_HOUR) {
delay = new Duration(DateTime.now() , DateTime.now().withTimeAtStartOfDay().plusHours(SELF_REMINDER_HOUR)).getStandardMinutes();
} else {
delay = new Duration(DateTime.now() , DateTime.now().withTimeAtStartOfDay().plusDays(1).plusHours(SELF_REMINDER_HOUR)).getStandardMinutes();
}
PeriodicWorkRequest workRequest = new PeriodicWorkRequest.Builder(
WorkerReminderPeriodic.class,
24,
TimeUnit.HOURS,
PeriodicWorkRequest.MIN_PERIODIC_FLEX_MILLIS,
TimeUnit.MILLISECONDS)
.setInitialDelay(delay, TimeUnit.MINUTES)
.addTag("send_reminder_periodic")
.build();
WorkManager.getInstance()
.enqueueUniquePeriodicWork("send_reminder_periodic", ExistingPeriodicWorkPolicy.REPLACE, workRequest);
到目前为止，还无法使用
PeriodicWorkRequestOneTimeWorkRequestOneTimeWorkRequest我可能有点晚了，但无论如何我这样做是为了在给定时间安排工作请求（可选的短暂延迟）。您只需要从 TimePicker 中获取时间即可：
public static void scheduleWork(int hour, int minute) {
Calendar calendar = Calendar.getInstance();
long nowMillis = calendar.getTimeInMillis();
calendar.set(Calendar.HOUR_OF_DAY,hour);
calendar.set(Calendar.MINUTE,minute);
calendar.set(Calendar.SECOND,0);
calendar.set(Calendar.MILLISECOND,0);
if (calendar.before(Calendar.getInstance())) {
calendar.add(Calendar.DATE, 1);
}
long diff = calendar.getTimeInMillis() - nowMillis;
WorkManager mWorkManager = WorkManager.getInstance();
Constraints constraints = new Constraints.Builder()
.setRequiredNetworkType(NetworkType.CONNECTED)
.build();
mWorkManager.cancelAllWorkByTag(WORK_TAG);
OneTimeWorkRequest mRequest = new OneTimeWorkRequest.Builder(NotificationWorker.class)
.setConstraints(constraints)
.setInitialDelay(diff,TimeUnit.MILLISECONDS)
.addTag(WORK_TAG)
.build();
mWorkManager.enqueue(mRequest);
}
您可以使用 Evernote 的 AndroidJob
class NotificationJob : DailyJob() {
override fun onRunDailyJob(params: Params): DailyJobResult {
//your job
return DailyJobResult.SUCCESS
}
companion object {
val TAG = "NotificationJob"
fun scheduleJob() {
//scheduled between 9-10 am
DailyJob.schedule(JobRequest.Builder(TAG),
TimeUnit.HOURS.toMillis(9),TimeUnit.HOURS.toMillis(10 ))
}
}
}
和通知创建者
class NotificationJobCreator : JobCreator {
override fun create(tag: String): Job? {
return when (tag) {
NotificationJob.TAG ->
NotificationJob()
else ->
null
}
}
}
然后在您的应用程序类中启动
JobManager.create(this).addJobCreator(NotificationJobCreator())
gradle 依赖项是
dependencies {
implementation 'com.evernote:android-job:1.2.6'
// or this with workmnager
implementation 'com.evernote:android-job:1.3.0-alpha08'
}
所有答案现已过时，升级到 WorkManager 2.1.0-alpha02（或更高版本） setInitialDelay() 方法过去仅适用于 OneTimeWorkRequest，但现在它们也支持PeriodicWorkRequest。
implementation "androidx.work:work-runtime:2.1.0-alpha02"
PeriodicWorkRequests 现在支持初始延迟。您可以使用 periodicworkRequest.Builder 上的 setInitialDelay 方法设置 初始延迟
快速示例：
new PeriodicWorkRequest.Builder(MyWorker.class, MY_REPEATS, TimeUnit.HOURS)
.setInitialDelay(THE_DELAY,TimeUnit.SECONDS);
如果您想为 PeriodicWorkRequest 设置初始延迟，我在这里提出了解决方案：
我尝试过 OneTimeWorkRequest 但它很不稳定（有时只能工作），所以我们不应该依赖它。 AlarmManager 是一个更好的选择。
我正在用这个 方法
private static Duration getRemainingDurationUntil(int hour) {
// Get the current time
LocalDateTime currentTime = LocalDateTime.now();
// Add one day to the current time
LocalDateTime nextDay = currentTime.plusDays(1);
// Set the target time to 3 AM of the next day
LocalDateTime targetTime = LocalDateTime.of(nextDay.toLocalDate(), LocalTime.of(hour, 0));
// Calculate the duration between the current time and hour
Duration duration = Duration.between(currentTime, targetTime);
// Get the remaining milliseconds
//long remainingMilliseconds = duration.toMillis();
return duration;
}
还有
Duration remainingDuration = getRemainingDurationUntil(REBIRTH_HOUR);
// Create a PeriodicWorkRequest to run the task every XX minutes
PeriodicWorkRequest periodicRebirthWorkRequest = new PeriodicWorkRequest.Builder(
Rebirth.class,
2, // Repeat interval
TimeUnit.DAYS
)
.addTag(TAG_4_REBIRTH_WORK)
.setInitialDelay(remainingDuration.toMinutes(),TimeUnit.MINUTES)
.setConstraints(constraints) // Set the constraints (optional)
.build();