这是正常的，它不返回任何内容，因为您需要在 WP_Query 中传递此 $args代码>首先以这种方式循环调用产品模板:

This is normal that it doesn't return anything as you need to pass this $args in a WP_Query first and to call a the product template in a loop this way:

if( ! function_exists('product_test') ) {

    // Add Shortcode
    function product_test( $atts ) {
        global $woocommerce_loop;

        // Attributes 
        $atts = shortcode_atts(
            array(
                'columns'   => '4',
                'limit'     => '20',
                'start'     => current_time('Ymd'),
                'end'       => current_time('Ymd'),
            ),
            $atts, 'products_test'
        );


        $woocommerce_loop['columns'] = $atts['columns'];
        
        // The WP_Query
        $products = new WP_Query( array (
            'post_type'         => 'product',
            'post_status'       => 'publish',
            'posts_per_page'    => $atts['limit'],
            'meta_query'        => array(
                'relation'      => 'AND',
                'start_clause'  => array(
                    'key'       =>'flash_sale_start',
                    'value'     => $atts['today'],
                    'compare'   => '<=',
                    'type'      => 'DATE'
                ),
                'end_clause'    => array(
                    'key'       => 'flash_sale_end',
                    'value'     => $atts['today'],
                    'compare'   => '>=',
                    'type'      => 'DATE'
                ),
            )
        ));

        ob_start();

        if ( $products->have_posts() ) { ?>

            <?php woocommerce_product_loop_start(); ?>

                <?php while ( $products->have_posts() ) : $products->the_post(); ?>

                    <?php wc_get_template_part( 'content', 'product' ); ?>

                <?php endwhile; // end of the loop. ?>

            <?php woocommerce_product_loop_end(); ?>

            <?php
        } else {
            do_action( "woocommerce_shortcode_products_loop_no_results", $atts );
            echo "<p>There is no results.</p>";
        }

        woocommerce_reset_loop();
        wp_reset_postdata();

        return '<div class="woocommerce columns-' . $atts['columns'] . '">' . ob_get_clean() . '</div>';
    }

    add_shortcode( 'products_test', 'product_test' );
}

代码位于活动子主题(或活动主题)的 function.php 文件中.

用法:

您可以将 4 个可用的可选参数添加到此短代码中:

There is 4 available optional arguments that you can add to this shortcode:

• columns(列数)- 默认为 4
• limit (产品数量| -1 将显示所有) - 默认为 20
• start(开始日期 | 格式为 'YMD' )- 默认为今天
• end(结束日期 | 格式为 'YMD' )- 默认为今天

• columns (The number of columns) - Default is 4
• limit (the number of products | -1 will display all ) - Default is 20
• start (Start date | format is 'YMD' ) - Default is today
• end (End date | format is 'YMD' ) - Default is today

您可以在函数中设置更多……您也可以更改默认值.

You can set any more in the function… You can change default values too.

示例 1(简单的默认值):

Example 1 (simple with default values):

[products_test]

示例 2(一些自定义值)

Example 2 (some custom values)

[products_test columns='3' limit='15']

经过测试并有效