小程序base64与buffer的总结

1.后台中字符转base64

 const buffer = Buffer.from(userInfo.nickName);
 let nickname = buffer.toString('base64');

2.后台中base64转字符

var buffer = new Buffer.from(user_info.nickname, 'base64')
nickName = buffer.toString();

3.base64转图片

需要在开始加上'data:image/png;base64,' +经行拼接