Is it useful to take the health code on your mobile phone with a camera and wash it out and take it with you? Is it effective?

The health code on the mobile phone, photographed with a camera, developed into a photo and taken with you, is effective in theory. But this printed health code photo is only valid on the same day. After this period of validity, it will be invalid.

The purpose of scanning the health code is to prove my real-time status. ..... At present, smart phones have become popular, and it is normal to scan health codes with smart phones.

However, for some people, scanning the health code is more troublesome. ..... such as students, or don't have their own mobile phones, or schools are not allowed to bring mobile phones; For example, the elderly are not familiar with the use of smart phones and will not scan health codes. ..... For these people, it will be very troublesome to scan the health code at any time ... At this time, you can ask someone to help them scan the health code, and then save the health code in your mobile phone or take a photo with you, which can also prove it. This is effective.

However, this printed health code is time-sensitive ... it is valid that day. If it expires, it will be invalid. Need to scan the code again.