Examples of pop-up date, drop-down list, pop-up menus, drop-down lists of linkage: https://www.cnblogs.com/bgwhite/p/9335648.html
A necessary condition for applet deployment: 1. must have a domain name, must be https 3. 2 best enterprise application of micro-channel public number.
Reproduced in: https: //www.cnblogs.com/liuyaping007/p/11062617.html