PHP 递归实现层级树状展现数据

lilingjie2015

<?php
$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('&nbsp;&nbsp;&nbsp;&nbsp;', $level) . $leaf['id'] . ' ' . $leaf['name'] . '<br/>';
foreach($tree as $l) {
if($l['fid'] == $leaf['id']) {
data2arr($tree, $leaf['id'], $level + 1);
break;
}
}
}
}
}
data2arr($data);
echo '<br/>-----------------------------------------------------------------------<br/>';
// 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($tree);
echo '<br/>-----------------------------------------------------------------------<br/>';
// 将数据使用HTML再次展现 见图3
function tree2html($tree) {
echo '<ul>';
foreach($tree as $leaf) {
echo '<li>' .$leaf['name'];
if(! empty($leaf['children'])) tree2html($leaf['children']);
echo '</li>';
}
echo '</ul>';
}
tree2html($tree);

　　图 1：

　　图 2：
　　

  图 3：