这不是一个选项卡，但您可以通过一个上载按钮开始。退房pre-upload-ui 以及接下来的一些行动。即pre-plupload-upload-ui 和post-upload-ui.

这将在\'Upload Files\' 制表符和收件人\'Media > Add New\'.

一零

add_action( \'pre-plupload-upload-ui\', \'wpse_20160202_pre_plupload_upload_ui\' );
add_action( \'post-upload-ui\', \'wpse_20160202_post_upload_ui\' );

function wpse_20160202_pre_plupload_upload_ui()
{
    # see https://core.trac.wordpress.org/browser/tags/4.4.1/src/wp-admin/includes/media.php#L1902

    print \'<button onclick="javascript:alert(\\\'Upload From Dropbox\\\');" id="db-upload-btn" class="button media-button button-primary button-large" style="margin-bottom:10px;">Upload From Dropbox</button>\';
}


function wpse_20160202_post_upload_ui()
{
    # see wp-includes/media-template.php

    print \'<button onclick="javascript:alert(\\\'Another Upload From Dropbox\\\');" id="db-upload-btn" class="button media-button button-primary button-large" style="margin-bottom:10px;">Another Upload From Dropbox</button>\';
}
TABS
将此添加到此处只是为了显示备用项。media_upload_tabs 将帮助您控制侧边和media_upload_{tab} 要呈现内容，请使用wp_iframe().
add_filter( \'media_upload_tabs\', \'media_upload_tabs__tab_slug\' );

function media_upload_tabs__tab_slug( $tabs ) {
    $newtab = array ( \'tab_slug\' => \'Your Tab Name\' );
    return array_merge( $tabs, $newtab );
}

add_action( \'media_upload_tab_slug\', \'media_upload_tab_slug__content\' );

function media_upload_tab_slug__content() {
    wp_iframe( \'media_upload_tab_slug_content__iframe\' );
}

function media_upload_tab_slug_content__iframe() {
    ?>
    <div>tab_slug: Add your content here.</div><?php
}