const reader = new FileReader();
reader.readAsDataURL(file);
reader.onload = function(){
console.log('图片', reader.result); //获取到base64格式图片
}
//将base64转换为文件
dataURLtoFile(dataurl, filename) {
var 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 });
}