Question

我需要在Ionic 2应用程序中使用swipeup / swipedown手势。当我做的时候

<div (swipe)='someFunction($event)'></div>

然后我的 someFunction(e) 被调用，但仅限于水平幻灯片 - 因此我无法听到上下滑动方向。 (swipeup) 和 (swipedown) 似乎根本不做任何事情。您是否知道Ionic beta是否可以实现这一点？

Answer 1

Ionic 2 makes use hammerjs library to handle its gestures.

They’ve also built their own Gesture class that effectively acts as a wrapper to hammerjs: Gesture.ts.

So you can do your own directive like:

import {Directive, ElementRef, Input, OnInit, OnDestroy} from 'angular2/core'
import {Gesture} from 'ionic-angular/gestures/gesture'
declare var Hammer: any

/*
  Class for the SwipeVertical directive (attribute (swipe) is only horizontal).

  In order to use it you must add swipe-vertical attribute to the component.
  The directives for binding functions are [swipeUp] and [swipeDown].

  IMPORTANT:
  [swipeUp] and [swipeDown] MUST be added in a component which
  already has "swipe-vertical".
*/

@Directive({
  selector: '[swipe-vertical]' // Attribute selector
})
export class SwipeVertical implements OnInit, OnDestroy {
  @Input('swipeUp') actionUp: any;
  @Input('swipeDown') actionDown: any;

  private el: HTMLElement
  private swipeGesture: Gesture
  private swipeDownGesture: Gesture

  constructor(el: ElementRef) {
    this.el = el.nativeElement
  }

  ngOnInit() {
    this.swipeGesture = new Gesture(this.el, {
      recognizers: [
          [Hammer.Swipe, {direction: Hammer.DIRECTION_VERTICAL}]
      ]
    });
    this.swipeGesture.listen()
    this.swipeGesture.on('swipeup', e => {
        this.actionUp()
    })
    this.swipeGesture.on('swipedown', e => {
        this.actionDown()
    })
  }

  ngOnDestroy() {
    this.swipeGesture.destroy()
  }
}

This code allows you to do something like this:

<div swipe-vertical [swipeUp]="mySwipeUpAction()" [swipeDown]="mySwipeDownAction()">

Answer 2

只是更新，Ionic现在有手势控制。见

http://ionicframework.com/docs/v2/components/#gestures

手势会返回$event个对象。您可以使用此数据来检查它是否是一个swipeup / swipedown事件。

See $event screenshot (since I can't attach images yet ;) )

离子2

2 个答案: