The curl_init function cannot be used. how can this problem be solved?

You cannot use the curl_init function Fatalerror: Calltoundefinedfunctioncurl_init (). This function has been loaded in php, but it still cannot be used. Copying related dll files to the system32 directory is not acceptable. This is why, check whether the php. ini file is a modified file and check phpinfo. In addition, the curl_init function cannot be used for modification.
Fatal error: Call to undefined function curl_init ()

This function has been loaded in php, but it still cannot be used.

Copy the related dll to the system32 directory. why?

------ Solution --------------------
Check whether the php. ini file is a modified file. after modification, restart apache... iis.
Check whether the extended dll file exists.
------ Solution --------------------
Expansion does not play a role
------ Solution --------------------
Add the corresponding modules,
------ Solution --------------------
View phpinfo directly and check whether the extension configuration is successful.