本文实例为大家分享了PHP递归实现层级树状展开的主要代码，供大家参考，具体内容如下

效果图：

实现代码：

$db = mysql_connect('localhost', 'root', 'root') or die('Can\'t connect to database');

mysql_select_db('test') or die('Can\'t find database : test');

$result = mysql_query('select id, fid, name from tree');

while($arr = mysql_fetch_array($result)){

$data[] = array(

'id' => $arr['id'],

'fid' => $arr['fid'],

'name' => $arr['name'],

);

}

// 将数据按照缩进简单排列 见图1

function data2arr($tree, $rootId = 0, $level = 0) {

foreach($tree as $leaf) {

if($leaf['fid'] == $rootId) {

echo str_repeat(' ', $level) . $leaf['id'] . ' ' . $leaf['name'] . '
';

foreach($tree as $l) {

if($l['fid'] == $leaf['id']) {

data2arr($tree, $leaf['id'], $level + 1);

break;

}

}

}

}

}

data2arr($data);

echo '
-----------------------------------------------------------------------
';

// 将数据按照所属关系封装 见图2

function arr2tree($tree, $rootId = 0) {

$return = array();

foreach($tree as $leaf) {

if($leaf['fid'] == $rootId) {

foreach($tree as $subleaf) {

if($subleaf['fid'] == $leaf['id']) {

$leaf['children'] = arr2tree($tree, $leaf['id']);

break;

}

}

$return[] = $leaf;

}

}

return $return;

}

$tree = arr2tree($data);

print_r($tree);

echo '
-----------------------------------------------------------------------
';

// 将数据使用HTML再次展现 见图3

function tree2html($tree) {

echo '

';

foreach($tree as $leaf) {

echo '

• ' .$leaf['name'];

  if(! emptyempty($leaf['children'])) tree2html($leaf['children']);

  echo '

';

}

echo '

';

}

tree2html($tree);

以上就是本文的全部内容，希望对大家学习php程序设计有所帮助。