本文实例讲述了PHP树形结构tree类用法。分享给大家供大家参考，具体如下：
<?php
include 'tree.class.php';
//模拟数据库
$data=array(
array('id'=>1,'pid'=>0,'name'=>'一级栏目一'),
array('id'=>2,'pid'=>0,'name'=>'一级栏目二'),
array('id'=>3,'pid'=>1,'name'=>'二级栏目一'),
array('id'=>4,'pid'=>3,'name'=>'三级栏目一'),
array('id'=>5,'pid'=>4,'name'=>'四级栏目一'),
);
//转换数据
$tree_data=array();
foreach ($data as $key=>$value){
$tree_data[$value['id']]=array(
'id'=>$value['id'],
'parentid'=>$value['pid'],
'name'=>$value['name']
);
}
/**
* 输出树形结构
*/
$str="<tr>
<td><input type='checkbox' name='list[\$id]' value='\$id'></td>
<td>\$id</td>
<td>\$spacer\$name</td>
<td><a href='add.php?id=\$id'>添加</a></td>
<td><a href='del.php?id=\$id'>删除</a></td>
<td><a href='update.php?id='\$id'>修改</a></td>
</tr>";
$tree=new Tree();
$tree->init($tree_data);
echo "<table>";
echo $tree->get_tree(0, $str);
echo "</table>";
echo "<br/>";
echo "<br/>";
echo "<br/>";
echo "<br/>";
/**
* 输出下拉列表
*/
$str="<option value=\$id \$selected>\$spacer\$name</option>";
$tree=new Tree();
$tree->init($tree_data);
echo "<select>";
echo $tree->get_tree(0, $str,2);
echo "</select>";
运行结果：
tree.class.php：
<?php
/**
* 通用的树型类，可以生成任何树型结构
*/
class tree {
/**
* 生成树型结构所需要的2维数组
* @var array
*/
public $arr = array();
/**
* 生成树型结构所需修饰符号，可以换成图片
* @var array
*/
public $icon = array('│','├','└');
public $nbsp = " ";
/**
* @access private
*/
public $ret = '';
/**
* 构造函数，初始化类
* @param array 2维数组，例如：
* array(
* 1 => array('id'=>'1','parentid'=>0,'name'=>'一级栏目一'),
* 2 => array('id'=>'2','parentid'=>0,'name'=>'一级栏目二'),
* 3 => array('id'=>'3','parentid'=>1,'name'=>'二级栏目一'),
* 4 => array('id'=>'4','parentid'=>1,'name'=>'二级栏目二'),
* 5 => array('id'=>'5','parentid'=>2,'name'=>'二级栏目三'),
* 6 => array('id'=>'6','parentid'=>3,'name'=>'三级栏目一'),
* 7 => array('id'=>'7','parentid'=>3,'name'=>'三级栏目二')
* )
*/
public function init($arr=array()){
$this->arr = $arr;
$this->ret = '';
return is_array($arr);
}
/**
* 得到父级数组
* @param int
* @return array
*/
public function get_parent($myid){
$newarr = array();
if(!isset($this->arr[$myid])) return false;
$pid = $this->arr[$myid]['parentid'];
$pid = $this->arr[$pid]['parentid'];
if(is_array($this->arr)){
foreach($this->arr as $id => $a){
if($a['parentid'] == $pid) $newarr[$id] = $a;
}
}
return $newarr;
}
/**
* 得到子级数组
* @param int
* @return array
*/
public function get_child($myid){
$a = $newarr = array();
if(is_array($this->arr)){
foreach($this->arr as $id => $a){
if($a['parentid'] == $myid) $newarr[$id] = $a;
}
}
return $newarr ? $newarr : false;
}
/**
* 得到当前位置数组
* @param int
* @return array
*/
public function get_pos($myid,&$newarr){
$a = array();
if(!isset($this->arr[$myid])) return false;
$newarr[] = $this->arr[$myid];
$pid = $this->arr[$myid]['parentid'];
if(isset($this->arr[$pid])){
$this->get_pos($pid,$newarr);
}
if(is_array($newarr)){
krsort($newarr);
foreach($newarr as $v){
$a[$v['id']] = $v;
}
}
return $a;
}
/**
* 得到树型结构
* @param int ID，表示获得这个ID下的所有子级
* @param string 生成树型结构的基本代码，例如："<option value=\$id \$selected>\$spacer\$name</option>"
* @param int 被选中的ID，比如在做树型下拉框的时候需要用到
* @return string
*/
public function get_tree($myid, $str, $sid = 0, $adds = '', $str_group = ''){
$number=1;
$child = $this->get_child($myid);
if(is_array($child)){
$total = count($child);
foreach($child as $id=>$value){
$j=$k='';
if($number==$total){
$j .= $this->icon[2];
}else{
$j .= $this->icon[1];
$k = $adds ? $this->icon[0] : '';
}
$spacer = $adds ? $adds.$j : '';
$selected = $id==$sid ? 'selected' : '';
@extract($value);
$parentid == 0 && $str_group ? eval("\$nstr = \"$str_group\";") : eval("\$nstr = \"$str\";");
$this->ret .= $nstr;
$nbsp = $this->nbsp;
$this->get_tree($id, $str, $sid, $adds.$k.$nbsp,$str_group);
$number++;
}
}
return $this->ret;
}
/**
* 同上一方法类似,但允许多选
*/
public function get_tree_multi($myid, $str, $sid = 0, $adds = ''){
$number=1;
$child = $this->get_child($myid);
if(is_array($child)){
$total = count($child);
foreach($child as $id=>$a){
$j=$k='';
if($number==$total){
$j .= $this->icon[2];
}else{
$j .= $this->icon[1];
$k = $adds ? $this->icon[0] : '';
}
$spacer = $adds ? $adds.$j : '';
$selected = $this->have($sid,$id) ? 'selected' : '';
@extract($a);
eval("\$nstr = \"$str\";");
$this->ret .= $nstr;
$this->get_tree_multi($id, $str, $sid, $adds.$k.' ');
$number++;
}
}
return $this->ret;
}
/**
* @param integer $myid 要查询的ID
* @param string $str 第一种HTML代码方式
* @param string $str2 第二种HTML代码方式
* @param integer $sid 默认选中
* @param integer $adds 前缀
*/
public function get_tree_category($myid, $str, $str2, $sid = 0, $adds = ''){
$number=1;
$child = $this->get_child($myid);
if(is_array($child)){
$total = count($child);
foreach($child as $id=>$a){
$j=$k='';
if($number==$total){
$j .= $this->icon[2];
}else{
$j .= $this->icon[1];
$k = $adds ? $this->icon[0] : '';
}
$spacer = $adds ? $adds.$j : '';
$selected = $this->have($sid,$id) ? 'selected' : '';
@extract($a);
if (empty($html_disabled)) {
eval("\$nstr = \"$str\";");
} else {
eval("\$nstr = \"$str2\";");
}
$this->ret .= $nstr;
$this->get_tree_category($id, $str, $str2, $sid, $adds.$k.' ');
$number++;
}
}
return $this->ret;
}
/**
* 同上一类方法，jquery treeview 风格，可伸缩样式（需要treeview插件支持）
* @param $myid 表示获得这个ID下的所有子级
* @param $effected_id 需要生成treeview目录数的id
* @param $str 末级样式
* @param $str2 目录级别样式
* @param $showlevel 直接显示层级数，其余为异步显示，0为全部限制
* @param $style 目录样式 默认 filetree 可增加其他样式如'filetree treeview-famfamfam'
* @param $currentlevel 计算当前层级，递归使用 适用改函数时不需要用该参数
* @param $recursion 递归使用 外部调用时为FALSE
*/
function get_treeview($myid,$effected_id='example',$str="<span class='file'>\$name</span>", $str2="<span class='folder'>\$name</span>" ,$showlevel = 0 ,$style='filetree ' , $currentlevel = 1,$recursion=FALSE) {
$child = $this->get_child($myid);
if(!defined('EFFECTED_INIT')){
$effected = ' id="'.$effected_id.'"';
define('EFFECTED_INIT', 1);
} else {
$effected = '';
}
$placeholder = '<ul><li><span class="placeholder"></span></li></ul>';
if(!$recursion) $this->str .='<ul'.$effected.' class="'.$style.'">';
foreach($child as $id=>$a) {
@extract($a);
if($showlevel > 0 && $showlevel == $currentlevel && $this->get_child($id)) $folder = 'hasChildren'; //如设置显示层级模式@2011.07.01
$floder_status = isset($folder) ? ' class="'.$folder.'"' : '';
$this->str .= $recursion ? '<ul><li'.$floder_status.' id=\''.$id.'\'>' : '<li'.$floder_status.' id=\''.$id.'\'>';
$recursion = FALSE;
if($this->get_child($id)){
eval("\$nstr = \"$str2\";");
$this->str .= $nstr;
if($showlevel == 0 || ($showlevel > 0 && $showlevel > $currentlevel)) {
$this->get_treeview($id, $effected_id, $str, $str2, $showlevel, $style, $currentlevel+1, TRUE);
} elseif($showlevel > 0 && $showlevel == $currentlevel) {
$this->str .= $placeholder;
}
} else {
eval("\$nstr = \"$str\";");
$this->str .= $nstr;
}
$this->str .=$recursion ? '</li></ul>': '</li>';
}
if(!$recursion) $this->str .='</ul>';
return $this->str;
}
/**
* 获取子栏目json
* Enter description here ...
* @param unknown_type $myid
*/
public function creat_sub_json($myid, $str='') {
$sub_cats = $this->get_child($myid);
$n = 0;
if(is_array($sub_cats)) foreach($sub_cats as $c) {
$data[$n]['id'] = iconv(CHARSET,'utf-8',$c['catid']);
if($this->get_child($c['catid'])) {
$data[$n]['liclass'] = 'hasChildren';
$data[$n]['children'] = array(array('text'=>' ','classes'=>'placeholder'));
$data[$n]['classes'] = 'folder';
$data[$n]['text'] = iconv(CHARSET,'utf-8',$c['catname']);
} else {
if($str) {
@extract(array_iconv($c,CHARSET,'utf-8'));
eval("\$data[$n]['text'] = \"$str\";");
} else {
$data[$n]['text'] = iconv(CHARSET,'utf-8',$c['catname']);
}
}
$n++;
}
return json_encode($data);
}
private function have($list,$item){
return(strpos(',,'.$list.',',','.$item.','));
}
}
?>
希望本文所述对大家PHP程序设计有所帮助。