yii有两种Breadcrumbs写法，
one:

echo Breadcrumbs::widget([    ‘itemTemplate‘ => "<li><i>{link}</i></li>\n", // template for all links    ‘links‘ => [        [            ‘label‘ => ‘Post Category‘,            ‘url‘ => [‘post-category/view‘, ‘id‘ => 10],            ‘template‘ => "<li><b>{link}</b></li>\n", // template for this link only        ],        [‘label‘ => ‘Sample Post‘, ‘url‘ => [‘post/edit‘, ‘id‘ => 1]],        ‘Edit‘,    ],]);

two:

echo Breadcrumbs::widget([    ‘links‘ => isset($this->params[‘breadcrumbs‘]) ? $this->params[‘breadcrumbs‘] : [],]);

第二种在yii的main.php中用实例，就是最简单home->edit;

今天将要说的第一种，

echo Breadcrumbs::widget([	‘itemTemplate‘ => "<li><i>{link}</i></li>\n", // template for all links	‘links‘ => $link,]);

由于此处需要使用breadcrumbs展现相应的tree结构，经过对link中的数据进行重组可以将程序写成上面的样子，

if (!empty($title)) {    $title = $title;    $title_arr = explode(‘/‘, $title);    foreach ($title_arr as $k => $item) {        if (!empty($item)) {            $link[] = [‘label‘ => $item, ‘url‘ => [‘/tree/edit/‘, ‘id‘ => $item, ‘type‘ => 1,]];        }    }    $title_s = ‘‘;    foreach ($link as $k => $item) {        if ($k !== 0) {            if ($k === 1) {                $title_s = $link[$k - 1][‘label‘];            } else {                $title_s = $title_s . ‘/‘ . $link[$k - 1][‘label‘];            }            $link[$k] = [‘label‘ => $item[‘label‘], ‘url‘ => [‘/tree/edit/‘, ‘id‘ => $item[‘label‘], ‘type‘ => 1, ‘title‘ => $title_s]];        } else {            $title_s = $item[‘label‘];        }    }    $title = $title . ‘/‘ . $node_id[‘nodeId‘];} else {    $title = $node_id[‘nodeId‘];}$link[] = $node_id[‘nodeId‘];

这样就展示了一个tree的结构

Yii2 使用小部件 Breadcrumbs