menduner-uniapp/utils/base64src.js

const fsm = wx.getFileSystemManager();

function base64src(base64data, fileName) {
  fileName = fileName || 'file_base64src'; //自定义文件名
  const [, format, bodyData] = /data:image\/(\w+);base64,(.*)/.exec(base64data) || [];
  if (!format) {
    return (new Error('ERROR_BASE64SRC_PARSE'));
  }
  const filePath = `${wx.env.USER_DATA_PATH}/${fileName}.${format}`;
  const buffer = wx.base64ToArrayBuffer(bodyData);
  return new Promise((resolve, reject) =>{
    fsm.writeFile({
        filePath,
        data: buffer,
        encoding: 'binary',
        success() {
            resolve(filePath);
        },
        fail() {
            reject(new Error('ERROR_BASE64SRC_WRITE'));
        },
    });
  })
};

export { base64src };