对自定义帖子类型类别和分类法感到困惑

Question

I created three Custom Post Types, one of them is called "TV". I also created a category in the WP dashboard that appears in all those three Custom Post Types as well the "Posts" too. I assigned several posts from those Custom Post Types and Posts to the category. However, when I tried to display the category both in "the_query" loop and the Category Posts Widget plugin, the category did not display the posts from the Custom Post Types. It only display posts that was from the "Posts".

I looked online and the Wordpress Codex in https://codex.wordpress.org/Function_Reference/register_post_type said that "When registering a post type, always register your taxonomies using the taxonomies argument".

I don't really get it. I thought that Taxonomy is same as Category, right? And that it's already called in register_post_type() when I added taxonomies' => array( 'category', 'post_tag' ) in this code below:

// Register Custom Post Type
function tvs_post_type() {

    $labels = array(
        'name'                  => _x( 'TV', 'Post Type General Name', 'text_domain' ),
        'singular_name'         => _x( 'TV', 'Post Type Singular Name', 'text_domain' ),
        'menu_name'             => __( 'TV', 'text_domain' ),
        'name_admin_bar'        => __( 'Post Type', 'text_domain' ),
        'archives'              => __( 'Item Archives', 'text_domain' ),
        'parent_item_colon'     => __( 'Parent TV:', 'text_domain' ),
        'all_items'             => __( 'All TVs', 'text_domain' ),
        'add_new_item'          => __( 'Add New Post', 'text_domain' ),
        'add_new'               => __( 'Add New Post', 'text_domain' ),
        'new_item'              => __( 'New Item', 'text_domain' ),
        'edit_item'             => __( 'Edit Post', 'text_domain' ),
        'update_item'           => __( 'Update Post', 'text_domain' ),
        'view_item'             => __( 'View Post', 'text_domain' ),
        'search_items'          => __( 'Search Posts', 'text_domain' ),
        'not_found'             => __( 'No posts found', 'text_domain' ),
        'not_found_in_trash'    => __( 'Not posts found in Trash', 'text_domain' ),
        'featured_image'        => __( 'Featured Image', 'text_domain' ),
        'set_featured_image'    => __( 'Set featured image', 'text_domain' ),
        'remove_featured_image' => __( 'Remove featured image', 'text_domain' ),
        'use_featured_image'    => __( 'Use as featured image', 'text_domain' ),
        'insert_into_item'      => __( 'Insert into item', 'text_domain' ),
        'uploaded_to_this_item' => __( 'Uploaded to this item', 'text_domain' ),
        'items_list'            => __( 'Items list', 'text_domain' ),
        'items_list_navigation' => __( 'Items list navigation', 'text_domain' ),
        'filter_items_list'     => __( 'Filter items list', 'text_domain' ),
    );
    $args = array(
        'label'                 => __( 'TV', 'text_domain' ),
        'description'           => __( 'tv information pages', 'text_domain' ),
        'labels'                => $labels,
        'supports'              => array( 'title', 'editor', 'excerpt', 'author', 'thumbnail', 'comments', 'custom-fields', ),
        'taxonomies'            => array( 'category', 'post_tag' ),
        'hierarchical'          => false,
        'public'                => true,
        'show_ui'               => true,
        'show_in_menu'          => true,
        'menu_position'         => 5,
        'show_in_admin_bar'     => true,
        'show_in_nav_menus'     => true,
        'can_export'            => true,
        'has_archive'           => true,        
        'exclude_from_search'   => false,
        'publicly_queryable'    => true,
        'capability_type'       => 'page',
    );
    register_post_type( 'tv', $args );

}
add_action( 'init', 'tvs_post_type', 0 );

Help? So confused....

Answer 1

Never mind. I figured most of it out. What is need to call the category for the Custom Post Types is to add post_type to the query as in

<?php 
    $args = array (
        'cat'              => 3,
        'post_type'        => array( 'post', 'tv', 'print', 'radio' ), //defined the post type. The default is post.
        'posts_per_page'   => 3
    );

     $the_query = new WP_Query( $args ); ?>
            <?php if ( $the_query->have_posts() ) : ?>

        <?php while ( $the_query->have_posts() ) : $the_query->the_post(); ?> 
           <?php the_title(); ?>
        <?php endwhile;  ?>

    <?php endif;
     wp_reset_postdata();
    ?>

As for the Category Posts Widget plugin, it looks like it only display the posts with the post_type => post in the query, I think? So I went with Ultimate Posts Widget plugin and it works.