function changeBase64() {
var imgSrc = './share.png'; // 图片本地路劲(写自己本地图片地址)
var image = new Image()
image.setAttribute('crossOrigin', 'anonymous') //支持跨域
image.src = imgSrc
image.onload = () => {
var canvas = document.createElement("canvas")
canvas.width = image.width
canvas.height = image.height
var ctx = canvas.getContext("2d")
ctx.drawImage(image, 0, 0, image.width, image.height)
var ext = image.src.substring(image.src.lastIndexOf(".") + 1).toLowerCase()
var dataUrl = canvas.toDataURL("image/" + ext)
var base64 = JSON.parse(JSON.stringify(dataUrl)) // 这里就是转化成的编码
console.log(base64)
}
}