1function getBase64(file) {
 2  return new Promise((res, rej) => {
 3    var reader = new FileReader();
 4    reader.onloadend = function () {
 5      res(reader.result);
 6    };
 7    reader.onerror = function (e) {
 8      rej(e);
 9    };
10    reader.readAsDataURL(file);
11  });
12}