Creates a new alarm for the current browser session. An alarm may fire once or multiple times. An alarm is cleared after it fires for the last time.
browser.alarms.create(
名称
,
// optional string
alarmInfo
// optional object
)
名称
可选
string
. A name for the alarm. Defaults to the empty string.
This can be used to refer to a particular alarm in
alarms.get()
and
alarms.clear()
. It will also be available in
alarms.onAlarm
作为
名称
特性为
alarms.Alarm
object passed into the listener function.
Alarm names are unique within the scope of a single extension. If an alarm with an identical name exists, the existing alarm will be cleared and the alarm being created will replace it.
alarmInfo
可选
对象
. You can use this to specify when the alarm will initially fire, either as an absolute value (
当
), or as a delay from the time the alarm is set (
delayInMinutes
). To make the alarm recur, specify
periodInMinutes
.
On Chrome, unless the extension is loaded unpackaged, alarms it creates are not allowed to fire more than once per minute. If an extension tries to set
delayInMinutes
to a value < 1, or
当
to a value < 1 minute in the future, then the alarm will fire after 1 minute. If an extension tries to set
periodInMinutes
to a value < 1, then the alarm will fire every minute.
alarmInfo
object may contain the following properties:
当
可选
double
. The time the alarm will fire first, given as
milliseconds since the epoch
. To get the number of milliseconds between the epoch and the current time, use
Date.now()
。若指定
当
, don't specify
delayInMinutes
.
delayInMinutes
可选
double
. The time the alarm will fire first, given as minutes from the time the alarm is set. If you specify
delayInMinutes
, don't specify
当
.
periodInMinutes
可选
double
. If this is specified, the alarm will fire again every
periodInMinutes
after its initial firing. If you specify this value you may omit both
当
and
delayInMinutes
, and the alarm will then fire initially after
periodInMinutes
。若
periodInMinutes
is not specified, the alarm will only fire once.
Create a one-time delay-based alarm with "" for the name:
const delayInMinutes = 5;
browser.alarms.create({
delayInMinutes
});
Create a periodic delay-based alarm named "my-periodic-alarm":
const delayInMinutes = 5;
const periodInMinutes = 2;
browser.alarms.create("my-periodic-alarm", {
delayInMinutes,
periodInMinutes
});
Create a periodic absolute alarm named "my-periodic-alarm":
const when = 1545696000;
const periodInMinutes = 2;
browser.alarms.create("my-periodic-alarm", {
when,
periodInMinutes
});
BCD tables only load in the browser
注意：
This API is based on Chromium's
chrome.alarms
API。
Microsoft Edge compatibility data is supplied by Microsoft Corporation and is included here under the Creative Commons Attribution 3.0 United States License.
最后修改： , 由 MDN 贡献者