libqrencode下载地址
https://fukuchi.org/works/qrencode
使用QRcode_encodeString()函数生成二维码数据
QRcode_encodeString()
QRcode* QRcode_encodeString ( const char * string,
int version,
QRecLevel level,
QRencodeMode hint,
int casesensitive
)
Create a symbol from the string.
The library automatically parses the inpu