禁止视频另存操作有步骤不解

Question

https://blog.csdn.net/yangjiaosun/article/details/114285802?ops_request_misc=%257B%2522request%255Fid%2522%253A%2522169545839416800184187454%2522%252C%2522scm%2522%253A%252220140713.130102334.pc%255Fall.%2522%257D&request_id=169545839416800184187454&biz_id=0&utm_medium=distribute.pc_search_result.none-task-blog-2~all~first_rank_ecpm_v1~rank_v31_ecpm-1-114285802-null-null.142^v94^insert_down1&utm_term=iis%E5%A6%82%E4%BD%95%E7%A6%81%E6%AD%A2%E8%A7%86%E9%A2%91%E5%8F%A6%E5%AD%98&spm=1018.2226.3001.4187
3、在页面中，加入以下代码
是哪 个页面中？