如何在我的 WordPress 插件中包含 CSS 和 jQuery

For styles wp_register_style( 'namespace', 'http://locationofcss.com/mycss.css' );

然后在希望加载CSS的任何位置使用:wp_enqueue_style('namespace');.

脚本与上面相同，但是加载jQuery的更快方法是只使用init中加载的enqueue来加载您想要加载的页面:wp_enqueue_script('jquery');

Unless of course you want to use the google repository for jquery.

You can also conditionally load the jquery library that your script is dependent on:

wp_enqueue_script('namespaceformyscript', 'http://locationofscript.com/myscript.js', array('jquery'));

Update Sept. 2017

I wrote this answer a while ago. I should clarify that the best place to enqueue your scripts and styles is within the wp_enqueue_scripts hook. So for example:

add_action('wp_enqueue_scripts', 'callback_for_setting_up_scripts');
function callback_for_setting_up_scripts() {
    wp_register_style( 'namespace', 'http://locationofcss.com/mycss.css' );
    wp_enqueue_style( 'namespace' );
    wp_enqueue_script( 'namespaceformyscript', 'http://locationofscript.com/myscript.js', array( 'jquery' ) );
}

The wp_enqueue_scripts action will set things up for the "frontend". You can use the admin_enqueue_scripts action for the backend (anywhere within wp-admin) and the login_enqueue_scripts action for the login page.