lucifer azl397985856

React是如何做到更新DOM，（focus）光标保持不变的？

支持esm的浏览器我们可以不polyfill，反之我们才需要polyfill。我们构建的时候需要打两份，如果将来规则更加细化，我们可以做到更加细致。当然这个东西可以做成服务化，类似polyfill.io

<script type="module" src="bundle.mjs"></script>

solution:

This is actually a macOS Gatekeeper issue try these steps:

To resolute Gatekeeper issues on macOS Sierra you might have to partially or completely disable Gatekeeper checks.

lsof -i :端口 
kill -9 进程ID

	import React, { Component } from 'react';
	import { render } from 'react-dom';

	// Get the position of the mouse relative to the canvas
	function getMousePos(canvasDom, mouseEvent) {
	var rect = canvasDom.getBoundingClientRect();
	return {
	x: mouseEvent.clientX - rect.left,
	y: mouseEvent.clientY - rect.top
	};

	import Taro, { Component } from '@tarojs/taro';
	import { Canvas, View, Image } from '@tarojs/components';
	import { AtButton } from 'taro-ui';


	function getTouchPos(e) {
	const rect = {
	left: 0,
	top: 0,
	};

	/**
	*
	* @param size 分段的大小
	* @param arr 需要被处理的数组
	*/
	function chunk<T>(size: number, arr: Array<T>): Array<Array<T>> {
	return Array.from({ length: Math.ceil(arr.length / size) }, (_, i) =>
	arr.slice(i * size, i * size + size)
	);
	}

	function check_webp_feature(feature, callback) {
	var kTestImages = {
	lossy: "UklGRiIAAABXRUJQVlA4IBYAAAAwAQCdASoBAAEADsD+JaQAA3AAAAAA",
	lossless: "UklGRhoAAABXRUJQVlA4TA0AAAAvAAAAEAcQERGIiP4HAA==",
	alpha: "UklGRkoAAABXRUJQVlA4WAoAAAAQAAAAAAAAAAAAQUxQSAwAAAARBxAR/Q9ERP8DAABWUDggGAAAABQBAJ0BKgEAAQAAAP4AAA3AAP7mtQAAAA==",
	animation: "UklGRlIAAABXRUJQVlA4WAoAAAASAAAAAAAAAAAAQU5JTQYAAAD/////AABBTk1GJgAAAAAAAAAAAAAAAAAAAGQAAABWUDhMDQAAAC8AAAAQBxAREYiI/gcA"
	};
	var img = new Image();
	img.onload = function () {
	var result = (img.width > 0) && (img.height > 0);

	window.addEventListener('pointermove', event => {
	const events = event.getCoalescedEvents();
	for (let event of events) {
	const x = event.pageX;
	const y = event.pageY;
	// draw a line using x and y coordinates.
	}
	});