harmony 鸿蒙@ohos.systemTimer (System Timer)

  • 2022-10-28
  • 浏览 (613)

@ohos.systemTimer (System Timer)

The systemTimer module provides system timer features. You can use the APIs of this module to implement the alarm clock and other timer services.

NOTE

  • The initial APIs of this module are supported since API version 7. Newly added APIs will be marked with a superscript to indicate their earliest API version.
  • The APIs provided by this module are system APIs.

Modules to Import

import systemTimer from '@ohos.systemTimer';

Constants

Provides the constants that define the supported timer types.

System capability: SystemCapability.MiscServices.Time

Name Type Value Description
TIMER_TYPE_REALTIME number 1 CPU time type. (The start time of the timer cannot be later than the current system time.)
TIMER_TYPE_WAKEUP number 2 Wakeup type.
TIMER_TYPE_EXACT number 4 Exact type.
TIMER_TYPE_IDLE number 8 Idle type (not supported currently).

## TimerOptions

Defines the initialization options for createTimer.

System capability: SystemCapability.MiscServices.Time

Name Type Mandatory Description
type number Yes Timer type.
1: CPU time type. (The start time of the timer cannot be later than the current system time.)
2: wakeup type.
4: exact type.
8: idle type (not supported currently).
repeat boolean Yes Whether the timer is a repeating timer.
The value true means that the timer is a repeating timer, and false means that the timer is a one-shot timer.
interval number No Repeat interval.
For a repeating timer, the value must be greater than 5000 ms. For a one-shot timer, the value is 0.
wantAgent WantAgent No WantAgent object of the notification to be sent when the timer expires. (An application MainAbility can be started, but not a Service ability.)
callback number Yes Callback used to return the timer ID.

systemTimer.createTimer

createTimer(options: TimerOptions, callback: AsyncCallback<number>): void

Creates a timer. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.MiscServices.Time

Parameters

Name Type Mandatory Description
options TimerOptions Yes Timer initialization options, including the timer type, whether the timer is a repeating timer, interval, and WantAgent options.
callback AsyncCallback<number> Yes Callback used to return the timer ID.

Example

import { BusinessError } from '@ohos.base';

let options: systemTimer.TimerOptions = {
  type: systemTimer.TIMER_TYPE_REALTIME,
  repeat: false
};
try {
  systemTimer.createTimer(options, (error: BusinessError, timerId: Number) => {
    if (error) {
      console.info(`Failed to create a timer. Message: ${error.message}, code: ${error.code}`);
      return;
    }
    console.info(`Succeeded in creating a timer. timerId: ${timerId}`);
  });
} catch(e) {
  let error = e as BusinessError;
  console.info(`Failed to create a timer. Message: ${error.message}, code: ${error.code}`);
}

systemTimer.createTimer

createTimer(options: TimerOptions): Promise<number>

Creates a timer. This API uses a promise to return the result.

System capability: SystemCapability.MiscServices.Time

Parameters

Name Type Mandatory Description
options TimerOptions Yes Timer initialization options, including the timer type, whether the timer is a repeating timer, interval, and WantAgent options.

Return value

Type Description
Promise<number> Promise used to return the timer ID.

Example

import { BusinessError } from '@ohos.base';

let options: systemTimer.TimerOptions = {
  type: systemTimer.TIMER_TYPE_REALTIME,
  repeat:false
};
try {
  systemTimer.createTimer(options).then((timerId: Number) => {
    console.info(`Succeeded in creating a timer. timerId: ${timerId}`);
  }).catch((error: BusinessError) => {
    console.info(`Failed to create a timer. Message: ${error.message}, code: ${error.code}`);
  });
} catch(e) {
  let error = e as BusinessError;
  console.info(`Failed to create a timer. Message: ${error.message}, code: ${error.code}`);
}

systemTimer.startTimer

startTimer(timer: number, triggerTime: number, callback: AsyncCallback<void>): void

Starts a timer. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.MiscServices.Time

Parameters

Name Type Mandatory Description
timer number Yes ID of the timer.
triggerTime number Yes Time when the timer is triggered, in milliseconds.
callback AsyncCallback<void> Yes Callback used to return the result.

Example

import { BusinessError } from '@ohos.base';

let options: systemTimer.TimerOptions = {
  type: systemTimer.TIMER_TYPE_REALTIME,
  repeat:false
}
let triggerTime = new Date().getTime();
triggerTime += 3000;

try {
  systemTimer.createTimer(options).then((timerId: number) => {
    systemTimer.startTimer(timerId, triggerTime, (error: BusinessError) => {
      if (error) {
        console.info(`Failed to start the timer. Message: ${error.message}, code: ${error.code}`);
        return;
      }
      console.info(`Succeeded in starting the timer.`);
    });
    console.info(`Succeeded in creating a timer. timerId: ${timerId}`);
  }).catch((error: BusinessError) => {
    console.info(`Failed to create a timer. Message: ${error.message}, code: ${error.code}`);
  });
} catch(e) {
  let error = e as BusinessError;
  console.info(`Failed to create a timer. Message: ${error.message}, code: ${error.code}`);
}

systemTimer.startTimer

startTimer(timer: number, triggerTime: number): Promise<void>

Starts a timer. This API uses a promise to return the result.

System capability: SystemCapability.MiscServices.Time

Parameters

Name Type Mandatory Description
timer number Yes ID of the timer.
triggerTime number Yes Time when the timer is triggered, in milliseconds.

Return value

Type Description
Promise<void> Promise that returns no value.

Example

import { BusinessError } from '@ohos.base';

let options: systemTimer.TimerOptions = {
  type: systemTimer.TIMER_TYPE_REALTIME,
  repeat:false
}
let triggerTime = new Date().getTime();
triggerTime += 3000;

try {
  systemTimer.createTimer(options).then((timerId: number) => {
    systemTimer.startTimer(timerId, triggerTime).then(() => {
      console.info(`Succeeded in starting the timer.`);
    }).catch((error: BusinessError) => {
      console.info(`Failed to start the timer. Message: ${error.message}, code: ${error.code}`);
    });
    console.info(`Succeeded in creating a timer. timerId: ${timerId}`);
  }).catch((error: BusinessError) => {
    console.info(`Failed to create a timer. Message: ${error.message}, code: ${error.code}`);
  });
} catch(e) {
  let error = e as BusinessError;
  console.info(`Failed to create a timer. Message: ${error.message}, code: ${error.code}`);
}

systemTimer.stopTimer

stopTimer(timer: number, callback: AsyncCallback&lt;void&gt;): void

Stops a timer. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.MiscServices.Time

Parameters

Name Type Mandatory Description
timer number Yes ID of the timer.
callback AsyncCallback&lt;void> Yes Callback used to return the result.

Example

import { BusinessError } from '@ohos.base';

let options: systemTimer.TimerOptions = {
  type: systemTimer.TIMER_TYPE_REALTIME,
  repeat:false
}
let triggerTime = new Date().getTime();
triggerTime += 3000;

try {
  systemTimer.createTimer(options).then((timerId: number) => {
    systemTimer.startTimer(timerId, triggerTime);
    systemTimer.stopTimer(timerId, (error: BusinessError) => {
      if (error) {
        console.info(`Failed to stop the timer. Message: ${error.message}, code: ${error.code}`);
        return;
      }
    console.info(`Succeeded in stopping the timer.`);
    });
    console.info(`Succeeded in creating a timer. timerId: ${timerId}`);
  }).catch((error: BusinessError) => {
    console.info(`Failed to create a timer. Message: ${error.message}, code: ${error.code}`);
  });
} catch(e) {
  let error = e as BusinessError;
  console.info(`Failed to create a timer. Message: ${error.message}, code: ${error.code}`);
}

systemTimer.stopTimer

stopTimer(timer: number): Promise&lt;void&gt;

Stops a timer. This API uses a promise to return the result.

System capability: SystemCapability.MiscServices.Time

Parameters

Name Type Mandatory Description
timer number Yes ID of the timer.

Return value

Type Description
Promise<void> Promise that returns no value.

Example

import { BusinessError } from '@ohos.base';

let options: systemTimer.TimerOptions = {
  type: systemTimer.TIMER_TYPE_REALTIME,
  repeat:false
}
let triggerTime = new Date().getTime();
triggerTime += 3000;

try {
  systemTimer.createTimer(options).then((timerId: number) => {
    systemTimer.startTimer(timerId, triggerTime);
    systemTimer.stopTimer(timerId).then(() => {
      console.info(`Succeeded in stopping the timer.`);
    }).catch((error: BusinessError) => {
      console.info(`Failed to stop the timer. Message: ${error.message}, code: ${error.code}`);
    });
    console.info(`Succeeded in creating a timer. timerId: ${timerId}`);
  }).catch((error: BusinessError) => {
    console.info(`Failed to create a timer. Message: ${error.message}, code: ${error.code}`);
  });
} catch(e) {
  let error = e as BusinessError;
  console.info(`Failed to create a timer. Message: ${error.message}, code: ${error.code}`);
}

systemTimer.destroyTimer

destroyTimer(timer: number, callback: AsyncCallback&lt;void&gt;): void

Destroys a timer. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.MiscServices.Time

Parameters

Name Type Mandatory Description
timer number Yes ID of the timer.
callback AsyncCallback&lt;void> Yes Callback used to return the result.

Example

import { BusinessError } from '@ohos.base';

let options: systemTimer.TimerOptions = {
  type: systemTimer.TIMER_TYPE_REALTIME,
  repeat:false
}
let triggerTime = new Date().getTime();
triggerTime += 3000;

try {
  systemTimer.createTimer(options).then((timerId: number) => {
    systemTimer.startTimer(timerId, triggerTime);
    systemTimer.stopTimer(timerId);
    systemTimer.destroyTimer(timerId, (error: BusinessError) => {
      if (error) {
        console.info(`Failed to destroy the timer. Message: ${error.message}, code: ${error.code}`);
        return;
      }
    console.info(`Succeeded in destroying the timer.`);
    });
    console.info(`Succeeded in creating a timer. timerId: ${timerId}`);
  }).catch((error: BusinessError) => {
    console.info(`Failed to create a timer. Message: ${error.message}, code: ${error.code}`);
  });
} catch(e) {
  let error = e as BusinessError;
  console.info(`Failed to create a timer. Message: ${error.message}, code: ${error.code}`);
}

systemTimer.destroyTimer

destroyTimer(timer: number): Promise&lt;void&gt;

Destroys a timer. This API uses a promise to return the result.

System capability: SystemCapability.MiscServices.Time

Parameters

Name Type Mandatory Description
timer number Yes ID of the timer.

Return value

Type Description
Promise<void> Promise that returns no value.

Example

import { BusinessError } from '@ohos.base';

let options: systemTimer.TimerOptions = {
  type: systemTimer.TIMER_TYPE_REALTIME,
  repeat:false
}
let triggerTime = new Date().getTime();
triggerTime += 3000;

try {
  systemTimer.createTimer(options).then((timerId: number) => {
    systemTimer.startTimer(timerId, triggerTime);
    systemTimer.stopTimer(timerId);
    systemTimer.destroyTimer(timerId).then(() => {
      console.info(`Succeeded in destroying the timer.`);
    }).catch((error: BusinessError) => {
      console.info(`Failed to destroy the timer. Message: ${error.message}, code: ${error.code}`);
    });
    console.info(`Succeeded in creating a timer. timerId: ${timerId}`);
  }).catch((error: BusinessError) => {
    console.info(`Failed to create a timer. Message: ${error.message}, code: ${error.code}`);
  });
} catch(e) {
  let error = e as BusinessError;
  console.info(`Failed to create a timer. Message: ${error.message}, code: ${error.code}`);
}

你可能感兴趣的鸿蒙文章

harmony 鸿蒙APIs

harmony 鸿蒙System Common Events (To Be Deprecated Soon)

harmony 鸿蒙System Common Events

harmony 鸿蒙API Reference Document Description

harmony 鸿蒙Enterprise Device Management Overview (for System Applications Only)

harmony 鸿蒙BundleStatusCallback

harmony 鸿蒙@ohos.bundle.innerBundleManager (innerBundleManager)

harmony 鸿蒙@ohos.distributedBundle (Distributed Bundle Management)

harmony 鸿蒙@ohos.bundle (Bundle)

harmony 鸿蒙@ohos.enterprise.EnterpriseAdminExtensionAbility (EnterpriseAdminExtensionAbility)

0  赞