先前寫過一篇文章：【組件篇】ionic3圖像手指縮放滑動預覽，是原來封裝的一個組件的原型，后來用ionic4后，這個組件不兼容，需要改，那時我開始考慮組件的封裝不依賴于ionic自身的組件，所以重寫了一個。
組件的核心是使用了PhotoSwipe，它是Github上一個熱門的開源項目，有近18K的star，可以上官網看效果，其中在手機端的效果如圖：
image.png
強調一下，PhotoSwipe響應式的，并支持手勢操作！
基于Angular封裝的版本，別人不是沒有做過，只是我覺得重新寫一個也很容易，便造了輪子。
封裝前，我們先分析下原生js方式使用：三步走。
- 第一步，它依賴這些文件，
<!-- Core CSS file -->
<link rel="stylesheet" href="path/to/photoswipe.css">
<!-- Skin CSS file (styling of UI - buttons, caption, etc.)
In the folder of skin CSS file there are also:
- .png and .svg icons sprite,
- preloader.gif (for browsers that do not support CSS animations) -->
<link rel="stylesheet" href="path/to/default-skin/default-skin.css">
<!-- Core JS file -->
<script src="path/to/photoswipe.min.js"></script>
<!-- UI JS file -->
<script src="path/to/photoswipe-ui-default.min.js"></script>
- 第二步，html中添加下面內容：
<!-- Root element of PhotoSwipe. Must have class pswp. -->
<div class="pswp" tabindex="-1" role="dialog" aria-hidden="true">
<!-- Background of PhotoSwipe.
It's a separate element as animating opacity is faster than rgba(). -->
<div class="pswp__bg"></div>
<!-- Slides wrapper with overflow:hidden. -->
<div class="pswp__scroll-wrap">
<!-- Container that holds slides.
PhotoSwipe keeps only 3 of them in the DOM to save memory.
Don't modify these 3 pswp__item elements, data is added later on. -->
<div class="pswp__container">
<div class="pswp__item"></div>
<div class="pswp__item"></div>
<div class="pswp__item"></div>
</div>
<!-- Default (PhotoSwipeUI_Default) interface on top of sliding area. Can be changed. -->
<div class="pswp__ui pswp__ui--hidden">
<div class="pswp__top-bar">
<!-- Controls are self-explanatory. Order can be changed. -->
<div class="pswp__counter"></div>
<button class="pswp__button pswp__button--close" title="Close (Esc)"></button>
<button class="pswp__button pswp__button--share" title="Share"></button>
<button class="pswp__button pswp__button--fs" title="Toggle fullscreen"></button>
<button class="pswp__button pswp__button--zoom" title="Zoom in/out"></button>
<!-- Preloader demo https://codepen.io/dimsemenov/pen/yyBWoR -->
<!-- element will get class pswp__preloader--active when preloader is running -->
<div class="pswp__preloader">
<div class="pswp__preloader__icn">
<div class="pswp__preloader__cut">
<div class="pswp__preloader__donut"></div>
</div>
</div>
</div>
</div>
<div class="pswp__share-modal pswp__share-modal--hidden pswp__single-tap">
<div class="pswp__share-tooltip"></div>
</div>
<button class="pswp__button pswp__button--arrow--left" title="Previous (arrow left)">
</button>
<button class="pswp__button pswp__button--arrow--right" title="Next (arrow right)">
</button>
<div class="pswp__caption">
<div class="pswp__caption__center"></div>
</div>
</div>
</div>
</div>
注意：別看內容那么多就嚇到了，其實里面就多了一些按鈕，你可以按需移除。
- 第三步，最后js初始化使用：
var pswpElement = document.querySelectorAll('.pswp')[0];
// build items array
var items = [
{
src: 'https://placekitten.com/600/400',
w: 600,
h: 400
},
{
src: 'https://placekitten.com/1200/900',
w: 1200,
h: 900
}
];
// define options (if needed)
var options = {
// optionName: 'option value'
// for example:
index: 0 // start at first slide
};
// Initializes and opens PhotoSwipe
var gallery = new PhotoSwipe(pswpElement, PhotoSwipeUI_Default, items, options);
gallery.init();
整個操作邏輯很簡單，代碼容易看得懂，所以我不過多解釋了，然后我們改造成Angular，如下幾步。
- npm安裝photoswipe依賴：
npm i photoswipe
- 創建Angular組件PhotoSwipeComponent，并在scss文件中導入樣式：
@import "~photoswipe/dist/photoswipe.css";
@import "~photoswipe/dist/default-skin/default-skin.css";
- html中添加先前說的dom部分（此處省略）。
- ts文件封裝方法：
import { Component, OnInit, Input, ChangeDetectorRef } from '@angular/core';
import * as PhotoSwipe from 'PhotoSwipe';
import * as PhotoSwipeUI_Default from 'photoswipe/dist/photoswipe-ui-default';
@Component({
selector: 'photo-swipe',
templateUrl: './photo-swipe.component.html',
styleUrls: ['./photo-swipe.component.scss']
})
export class PhotoSwipeComponent implements OnInit {
constructor(private cd: ChangeDetectorRef) { }
ngOnInit() {
}
open(images: PhotoSwipe.Item[], options?: any) {
this.cd.detectChanges();
const pswpEle: any = document.querySelectorAll('.pswp')[0];
// define options (if needed)
if (!options) {
options = {
// optionName: 'option value' for example:
index: 0 // start at first slide
};
}
// Initializes and opens PhotoSwipe
const gallery = new PhotoSwipe(pswpEle, PhotoSwipeUI_Default, images, options);
gallery.init();
}
}
這樣組件就完成了，使用時這樣應用：
在任何文件任何地方放置這樣一個組件:
<photo-swipe></photo-swipe>
然后如下調用：
@ViewChild(PhotoSwipeComponent)
photoSwipe: PhotoSwipeComponent;
……
this.photoSwipe.open(imgList);
