The two-dimensional code picture is not edited correctly, resulting in code scanning error.

When scanning the QR code, I made a mistake in my own operation, which made it impossible to scan the code.

The QR code is not on the platform, resulting in code scanning failure.

Duplicate QR code, resulting in QR code scanning failure.

Knowledge supplement: 2D barcode/QR code records data symbol information with a certain geometric figure distributed in a plane (two-dimensional direction) in black and white; In coding, the concepts of "0" and "1" bit streams, which constitute the internal logic foundation of a computer, are skillfully used, and several geometric figures corresponding to binary systems are used to represent numerical information of characters, which can be automatically read by image input equipment or photoelectric scanning equipment to realize automatic information processing: it has some characteristics of bar code technology: each code system has its own specific character set; Each character occupies a certain width; It has certain verification function, etc. At the same time, it also has the function of automatic identification of different lines of information and processing of graphic rotation change points.