项目中图片转base64 下载-优快云博客

本文链接：https://blog.youkuaiyun.com/Autumn_yun/article/details/131589627

这段代码展示了如何从图片源生成Base64编码，然后将Base64编码转换回图片并保存。它使用了HTML5的CanvasAPI来绘制图片并提取数据，接着创建Blob对象和URL以供下载。

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savePicture(){
var arr = this.codeBase64.split(‘,’);
var bytes = atob(arr[1]);
let ab = new ArrayBuffer(bytes.length);
let ia = new Uint8Array(ab);
for (let i = 0; i < bytes.length; i++) {
ia[i] = bytes.charCodeAt(i);
}
var blob = new Blob([ab], { type: ‘application/octet-stream’ });
var url = URL.createObjectURL(blob);
var a = document.createElement(‘a’);
a.href = url;
a.download = new Date().valueOf() + “.png”;
var e = document.createEvent(‘MouseEvents’);
e.initMouseEvent(‘click’, true, false, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null);
a.dispatchEvent(e);
URL.revokeObjectURL(url);
},
getImage2Base64(img) {
let canvas = document.createElement(‘canvas’)
canvas.width = img.width
canvas.height = img.height
let ctx = canvas.getContext(‘2d’)
ctx.drawImage(img, 0, 0, img.width, img.height)
let ext = img.src.substring(img.src.lastIndexOf(‘.’) + 1).toLowerCase()
this.codeBase64=canvas.toDataURL(‘image/’ + ext)
},
getBase64(){
let base64 = ‘’
let img = new Image()
img.src = require(‘…/…/…/static/shopping/code.png’)
img.onload = () => {
base64 = this.getImage2Base64(img)
}
},