如果图像存在，我该如何才显示图像？

Question

我对php很新，并且在弄清楚我做错了什么时遇到了一些麻烦。出于某种原因，kd_mfi_the_featured_image( 'featured-image-3', 'post' );不存在（即使它上传并且在单词按管理面板中看起来很好），因此它不是= true并且不会显示。

目标是仅在 feature-image-3存在时才显示所有子页面的精选图像3（我使用此plugin来显示多个精选图像）。我的方法如下

1. 获取当前页面ID
2. 使用当前页面ID查询子页面
3. 如果有子页面设置每个子页面的发布数据
4. 检查子页面是否有feature-image-3
5. 如果子页面有feature_image-3 显示：如果不是查询下一篇文章

customPage.php中的代码

<?php if ( have_posts() ) {  /* Query and display the parent. */
while ( have_posts() ) {
the_post();
the_content();
$thispage=$post->ID;
}

}？＆gt;

<?php $childpages = query_posts('post_type=page&post_parent='.$thispage);
if($childpages) /* display the children content  */
        foreach ($childpages as $post) :
        setup_postdata($post); 
            if (kd_mfi_the_featured_image( 'featured-image-3', 'post' )) {

                    kd_mfi_the_featured_image( 'featured-image-3', 'post' );
                    the_post_thumbnail();

            } 
            else {
                $wp_query->next_post();
            } 


        endforeach; ?>

Functions.php中的代码

if( class_exists( 'kdMultipleFeaturedImages' ) ) {

    $args2 = array(
            'id' => 'featured-image-2',
            'post_type' => 'page',      // Set this to post or page
            'labels' => array(
                'name'      => 'Home Page Carousel',
                'set'       => 'Set Home Page Carousel',
                'remove'    => 'Remove Home Page Carousel',
                'use'       => 'Use as Home Page Carousel',
            )
    );

    $args3 = array(
            'id' => 'featured-image-3',
            'post_type' => 'page',      // Set this to post or page
            'labels' => array(
                'name'      => 'Product Category Hero',
                'set'       => 'Set Product Category Hero',
                'remove'    => 'Remove Product Category Hero',
                'use'       => 'Use as Product Category Hero',
            )
    );

    $args4 = array(
            'id' => 'featured-image-4',
            'post_type' => 'page',      // Set this to post or page
            'labels' => array(
                'name'      => 'Product Category Featured',
                'set'       => 'Set Product Category Featured',
                'remove'    => 'Remove Product Category Featured',
                'use'       => 'Use as Product Category Featured',
            )
    );

    new kdMultipleFeaturedImages( $args2);
    new kdMultipleFeaturedImages( $args3 );
    new kdMultipleFeaturedImages( $args4 );

}