首先参考：Composer三步曲：安装、使用、发布
在 php 路径下，应能打开命令行输入php -v能够看到php版本信息。
然后执行以下三条：
php -r "copy('https://install.phpcomposer.com/installer', 'composer-setup.php');"php composer-setup.phpphp -r "unlink('composer-setup.php');"
这时遇到报错：
Unable to find the wrapper "https" - did you forget to enable it when you configured PHP?
参考：https://www.cnblogs.com/ec04/p/12390050.html
1.windows下的PHP，只需要到php.ini中把extension=php_openssl.dll前面的;删掉，重启服务就可以了。
经查，我的 php 没有这一项，添加，然后 iisreset 。再次执行以上三条，通过，下载安装成功。
All settings correct for using Composer
Downloading...
Composer (version 2.7.7) successfully installed to: C:\php\composer.phar
Use it: php composer.phar
C:\php>php comoser.phar
Could not open input file: comoser.phar
C:\php>php composer.phar
______
/ ____/___ ____ ___ ____ ____ ________ _____
/ / / __ \/ __ `__ \/ __ \/ __ \/ ___/ _ \/ ___/
/ /___/ /_/ / / / / / / /_/ / /_/ (__ ) __/ /
\____/\____/_/ /_/ /_/ .___/\____/____/\___/_/
/_/
Composer version 2.7.7 2024-06-10 22:11:12
最后参考：php使用wkhtmltopdf html转为ptf或图片_php wkhtmlto-CSDN博客
执行：composer require mikehaertl/phpwkhtmltopdf
这时有问题，需要改为：php composer.phar require mikehaertl/phpwkhtmltopdf
执行通过：
./composer.json has been created
Running composer update mikehaertl/phpwkhtmltopdf
Loading composer repositories with package information
Updating dependencies
Lock file operations: 3 installs, 0 updates, 0 removals
- Locking mikehaertl/php-shellcommand (1.7.0)
- Locking mikehaertl/php-tmpfile (1.2.1)
- Locking mikehaertl/phpwkhtmltopdf (2.5.0)
Writing lock file
Installing dependencies from lock file (including require-dev)
Package operations: 3 installs, 0 updates, 0 removals
- Downloading mikehaertl/php-tmpfile (1.2.1)
- Downloading mikehaertl/php-shellcommand (1.7.0)
- Downloading mikehaertl/phpwkhtmltopdf (2.5.0)
0/3 [>---------------------------] 0%
2/3 [==================>---------] 66%
3/3 [============================] 100%
- Installing mikehaertl/php-tmpfile (1.2.1): Extracting archive
- Installing mikehaertl/php-shellcommand (1.7.0): Extracting archive
- Installing mikehaertl/phpwkhtmltopdf (2.5.0): Extracting archive
0/3 [>---------------------------] 0%
3/3 [============================] 100%
Generating autoload files
No security vulnerability advisories found.
Using version ^2.5 for mikehaertl/phpwkhtmltopdf
