方法：
dataURLtoFile(dataurl, filename) {
let arr = dataurl.split(","),
mime = arr[0].match(/:(.*?);/)[1],
bstr = atob(arr[1]),
n = bstr.length,
u8arr = new Uint8Array(n);
while (n--) {
u8arr[n] = bstr.charCodeAt(n);
}
return new File([u8arr], filename, { type: mime });
},
使用：
this.blobFile = this.dataURLtoFile(base64, 'camera.jpg');
console.log(this.blobFile);
