Scheduler

Cocos Creator provides a powerful, flexible and convenient timer component.

Using the Scheduler

  1. Start a timer

     this.schedule(function() {
         // Here this refers to component
         this.doSomething();
     }, 5);
    

    The above timer will be executed every 5s.

  2. A more flexible timer

     // time interval in seconds
     let interval = 5;
     // number of times to repeat
     let repeat = 3;
     // delay starts
     let delay = 10;
     this.schedule(function() {
         // Here this refers to component
         this.doSomething();
     }, interval, repeat, delay);
    

    The above timer will start timing after 10 seconds, and execute a callback every 5 seconds, repeating 3 times.

  3. Timer that executes only once (shortcut)

     this.scheduleOnce(function() {
         // Here this refers to component
         this.doSomething();
     }, 2);
    

    The timer above will execute the callback function once after two seconds, and then stop timing.

  4. Cancel a timer

    Developers can use the callback function itself to cancel the timer:

     this.count = 0;
     this.callback = function () {
         if (this.count == 5) {
             // Cancel this timer when the callback is executed 
             // for the sixth time
             this.unschedule(this.callback);
         }
         this.doSomething();
         this.count++;
     }
     this.schedule(this.callback, 1);
    

Note: when the component's timer calls the callback, the this of the callback is specified as the component itself, so this can be used directly in the callback.

Here is a list of all of the timer functions in Component:

  • schedule: start a timer
  • scheduleOnce: start a timer that is executed only once
  • unschedule: cancel a timer
  • unscheduleAllCallbacks: cancel all timers of this component

The detailed description of these APIs can be found in the API documentation.

In addition, if developers need to execute a function every frame, please add the update function directly to the Component. This function will be called every frame by default. This is described in Lifecycle Document.

Note: Node does not include timer related APIs

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