下载base64图片

下载

this.downloadFile('二维码',that.img64)

downloadFile(fileName, content) {
let aLink = document.createElement('a')
let blob = this.base64ToBlob(content) // new Blob([content]);
let evt = document.createEvent('HTMLEvents')
evt.initEvent('click', true, true)// initEvent 不加后两个参数在FF下会报错 事件类型，是否冒泡，是否阻止浏览器的默认行为
aLink.download = fileName
aLink.href = URL.createObjectURL(blob)
// aLink.dispatchEvent(evt);
aLink.click()
},

// base64转blob
base64ToBlob(code) {
let parts = code.split(';base64,')
let contentType = parts[0].split(':')[1]
let raw = window.atob(parts[1]) // 解码base64得到二进制字符串
let rawLength = raw.length
let uInt8Array = new Uint8Array(rawLength) // 创建8位无符号整数值的类型化数组
for (let i = 0; i < rawLength; ++i) {
uInt8Array[i] = raw.charCodeAt(i) // 数组接收二进制字符串
}
return new Blob([uInt8Array], {type: contentType})
},