Question

我试图为我的Ionic2应用程序制作一个倒计时器，问题是我从现在开始使用这种方法countdown timer但现在我必须创建倒计时30:00分钟，什么＆＃39;更好的方法吗？时间可能会发生变化，如果我想在倒计时时点火，我只需要比较time，如果它是0，对吧？

Answer 1

您可以'收听'计时器并在倒计时为0时触发操作。要显示计时器，请使用管道。

<强> HTML

<h2>{{countDown | async | formatTime}}</h2>

<button [disabled]="counter == 0">OK</button>

<强>打字稿

  countDown;
  counter = 30*60;
  tick = 1000;
  ngOnInit() {
    this.countDown = Observable.timer(0, this.tick)
      .take(this.counter)
      .map(() => --this.counter)
  }

<强>管

//for MM:SS format

@Pipe({
  name: 'formatTime'
})
export class FormatTimePipe implements PipeTransform {

    transform(value: number): string {
      const minutes: number = Math.floor(value/60);
      return ('00'+ minutes).slice(-2) + ':' + ('00'+Math.floor(value-minutes * 60)).slice(-2);
    }

}

<强> DEMO

//for HH:MM:SS format

transform(value: number): string {
    const hours: number = Math.floor(value / 3600);
    const minutes: number = Math.floor((value % 3600) / 60);
    return ('00' + hours).slice(-2) + ':' + ('00' + minutes).slice(-2) + ':' + ('00' + Math.floor(value - minutes * 60)).slice(-2);
}

DEMO

<小时/> 如果您想使用服务：

<强>服务

 ...
 getCounter() {
    return Observable.timer(0, this.tick)
      .take(this.counter)
      .map(() => --this.counter)
  }
 ...

<强>组件

@Component({
  ...
  providers: [MyService]
})
...
constructor(private myService: MyService) {}
ngOnInit(){
    this.countDown = this.myService.getCounter().do(() => --this.counter);
    //or 
    //this.countDown = myService.getCounter();
}
...

<强>管

  ...  
  transform(value: number): string {
    //MM:SS format
    const minutes: number = Math.floor(value / 60);
    return ('00' + minutes).slice(-2) + ':' + ('00' + Math.floor(value - minutes * 60)).slice(-2);

    // for HH:MM:SS
    //const hours: number = Math.floor(value / 3600);
    //const minutes: number = Math.floor((value % 3600) / 60);
    //return ('00' + hours).slice(-2) + ':' + ('00' + minutes).slice(-2) + ':' + ('00' + Math.floor(value - minutes * 60)).slice(-2);

  }

DEMO

Answer 2

尝试使用此计时器：

<h5><span id="time" class="text-primary">00:00</span></h5>

<强> component.ts

import { Component, OnInit, ElementRef, AfterViewInit } from '@angular/core';
import { Observable } from 'rxjs/Rx';

export class AppComponent implements OnInit {

    constructor(private elementRef: ElementRef) { }

    ngOnInit() {
        var callDuration = this.elementRef.nativeElement.querySelector('#time');
        this.startTimer(callDuration);
    }

    startTimer(display) {
        var timer = 1800;
        var minutes;
        var seconds;

        Observable.interval(1000).subscribe(x => {
            minutes = Math.floor(timer / 60);
            seconds = Math.floor(timer % 60);

            minutes = minutes < 10 ? "0" + minutes : minutes;
            seconds = seconds < 10 ? "0" + seconds : seconds;

            display.textContent = minutes + ":" + seconds;

            --timer;
            if (--timer < 0) {
                 console.log('timeup');
            }
        })
    }
}

Answer 3

maxtime: any=30

  StartTimer(){
    this.timer = setTimeout(x => 
      {
          if(this.maxTime <= 0) { }
          this.maxTime -= 1;

          if(this.maxTime>0){
            this.hidevalue = false;
            this.StartTimer();
          }

          else{
              this.hidevalue = true;
          }

      }, 1000);


  }

计时器倒计时Angular 2

3 个答案: