为什么WordPress附件LINK TO设置不起作用？

Question

使用下面的代码，我为内容的所有图像添加了一些悬停共享图标。但是，现在这些图像没有得到作者的任何“链接到”设置。我不知道是什么问题。有谁可以请看下面的代码并指导我？

public function 
    Add_Pin_Button($content){
            global $post;

        // Get the post urls
        $posturl = urlencode(get_permalink());

        // Define a pattern to find all images inside the content
        $pattern = '/<img(.*?)src="(.*?).(bmp|gif|jpeg|jpg|png)" (.*?) width="(.*?)" height="(.*?)" \/>/i';

        // Replace the images with the following div and pin button
        $button_div = '<div class="democlass">
        <div class="secondclass">
            <div class="thirdclass">
                <a href="http://www.facebook.com/share.php?u=' . get_permalink().'&title='.get_the_title().'">
                    <img src="http://www.example.com/wp-content/facebook.png" width="45px" />
                </a>
            </div>

        </div>

            <div class="disdemo"><img$1src="$2.$3" $4 width="$5" height="$6" /></div> </div>
            ';

        // Replace the images with a containing div with a pin button on the image
        $content = preg_replace( $pattern, $button_div, $content );

        return $content;
    }

如何为内容的所有图片添加附件链接？