百度智能小程序 IntersectionObserver

IntersectionObserver

解釋?zhuān)?IntersectionObserver 對(duì)象，用于推斷某些節(jié)點(diǎn)是否可以被用戶看見(jiàn)、有多大比例可以被用戶看見(jiàn)。

屬性說(shuō)明

示例 

在開(kāi)發(fā)者工具中打開(kāi)

代碼示例

<view class="wrap">
    <view class="message">
        <text s-if="appear">小球出現(xiàn)</text>
        <text s-else>小球消失</text>
    </view>
    <scroll-view class="scroll-view" scroll-y>
        <view class="scroll-area" style="{{appear ? 'background: #ccc' : ''}}">
            <text class="notice">向下滾動(dòng)讓小球出現(xiàn)</text>
            <view class="filling"></view>
            <view class="ball"></view>
        </view>
    </scroll-view> 
</view>

Page({
    onReady() {
        this.intersectionObserver = swan.createIntersectionObserver(this);
        this.intersectionObserver
            .relativeTo('.scroll-view')
            .relativeToViewport({bottom: 100})
            .observe('.ball', res => {
                console.log('observe', res)
            });
    },
    onUnload() {
        this.intersectionObserver && this.intersectionObserver.disconnect();
    }
});