我目前正在创建一个自定义帖子类型，我想添加一些自定义元框。除了一个复选框字段，所有字段都按预期运行，它在回显隐藏字段后打印在html checked=\'checked\'上，我不知道为什么。我试着不回应这个值或引用，但还是发生了。这是我的代码：

  //Add Zoom Activity Status
     add_meta_box(
         \'zact_zoom_activity_state\',   
         \'Zoom Activity Comming Soon\',           
         \'zact_zoom_activity_status\',  
         \'zoom-activity\',                  
         \'advanced\',
         \'core\'
     );
 
     function zact_zoom_activity_status () 
     {
         global $post;
         // Get the location data if it\'s already been entered
         $zoom_activity_state = get_post_meta( $post->ID, \'zoom_activity_state\', true );
 
        // Nonce field to validate form request came from current site
        wp_nonce_field( plugin_basename(__FILE__),\'zoom_room_state\') ;
 
 
         // Output the field
         echo \'<lable for="zoom_activity_state"> <input type="checkbox" name="zoom_activity_state" value="\' . $zoom_activity_state . \'" class="widefat" \' . checked($zoom_activity_state)  . \'/> Is comming soon?</lable>\';
     }

这是我得到的不想要的结果：

这是保存代码：

// Verify this came from the our screen and with proper authorization,
// because save_post can be triggered at other times. The checked value is being retrived from the nonce name field.
if ( ! isset( $_POST[\'zoom_room_state\'] ) || ! wp_verify_nonce( $_POST[\'zoom_room_state\'], plugin_basename(__FILE__) ) ) 
{
    return $post_id;
}
// If the field is a checkbox we need to check if the value is not null and assing a boolean value to be compared when setting the status.
if( isset( $_POST[\'zoom_activity_state\'] )) 
{
    $zoom_activity_meta[\'zoom_activity_state\']              = true;
}
else 
{
    $zoom_activity_meta[\'zoom_activity_state\']              = false;

}//循环浏览zoom\\u activity\\u元数组。//注意，在本例中，我们只有一个项目，但如果您有多个项目，这将非常有用。foreach（$zoom\\u activity\\u meta as$键=>；$值）：

    // Don\'t store custom data twice
    if ( \'revision\' === $post->post_type ) {
        return;
    }

    if ( get_post_meta( $post_id, $key, true ) ) {
        // If the custom field already has a value, update it.
        update_post_meta( $post_id, $key, $value );
    } else {
        // If the custom field doesn\'t have a value, add it.
        add_post_meta( $post_id, $key, $value);
    }

    if ( ! $value ) {
        // Delete the meta key if there\'s no value
        delete_post_meta( $post_id, $key );
    }

endforeach;

我真不知道我做错了什么。我查阅了wordpress文档和互联网上的其他文章，但在这方面没有明确的内容。有什么线索吗？谢谢

echo \'<lable for="zoom_activity_state"> <input type="checkbox" name="zoom_activity_state" value="\' . $zoom_activity_state . \'" class="widefat" \' . checked($zoom_activity_state, true, false)  . \'/> Is comming soon?</lable>\';

echo \'<label for="zoom_activity_state"> <input type="checkbox" name="zoom_activity_state" value="\' . $zoom_activity_state . \'" class="widefat" \' . checked($zoom_activity_state, true, false)  . \'/> Is comming soon?</label>\';