.htaccess将url更改为查询字符串的一部分并附加.html扩展名

I am trying to change the following URL:

   http://localhost/app/site/?page=12&module=custom&title=Swat_Medical_College-_The_Project_of_Swat_Medical_Complex

To this URL:

   http://localhost/app/site/12/custom/Swat_Medical_College-_The_Project_of_Swat_Medical_Complex.html

I have tried too many options to make it functional but in vain...

 RewriteEngine On
 RewriteRule ^/(\d+)/([a-z-]+) index.php?page=$1&module=$2&title=$3 [L]

it throws an 404 error page not found... Please help me to solve the above url conversion thanks in advance. Also please if there is any easy and basic tutorial regarding url rewriting, i will be really very appreciate it. thanks

This is probably the rule you are looking for:

RewriteEngine on
RewriteRule ^/app/site/(\d+)/([a-z-]+)/(.+)\.html$ /app/site/index.php?page=$1&module=$2&title=$3 [L,B]

That would do what you sketch in your question. I am not sure though if that really is you situation. But you will probably be able to adapt it to your needs.

For details I can only recommend to take a look into the official documentation of Apache's rewriting module, as mentioned in the comment above. It is very technical, yes. But it is also very well written, extremely precise, and comes with really good examples.