php 无限级分类，超级简单的无限级分类，支持输出树状图

无平台限制
只需要告知id,parentid,name 即可
<?phperror_reporting（E_ALL ^ E_NOTICE）;class Tree{ /** +------------------------------------------------ * 生成树型结构所需要的2维数组 +------------------------------------------------ * @author abc +------------------------------------------------ * @var Array */var $arr = array（）; /** +------------------------------------------------ * 生成树型结构所需修饰符号，可以换成图片 +------------------------------------------------ * @author abc +------------------------------------------------ * @var Array */var $icon = array（" │"," ├"," └"）; /*** @access private*/var $ret = ""; /*** 构造函数，初始化类* @param array 2维数组，例如：* array（* 1 => array（"id"=>"1","parentid"=>0,"name"=>"一级栏目一"）,* 2 => array（"id"=>"2","parentid"=>0,"name"=>"一级栏目二"）,* 3 => array（"id"=>"3","parentid"=>1,"name"=>"二级栏目一"）,* 4 => array（"id"=>"4","parentid"=>1,"name"=>"二级栏目二"）,* 5 => array（"id"=>"5","parentid"=>2,"name"=>"二级栏目三"）,* 6 => array（"id"=>"6","parentid"=>3,"name"=>"三级栏目一"）,* 7 => array（"id"=>"7","parentid"=>3,"name"=>"三级栏目二"）* ）*/function tree（$arr=array（））{$this->arr = $arr;$this->ret = "";return is_array（$arr）;} /*** 得到父级数组* @param int* @return array*/function get_parent（$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 $newarr;} /*** 得到子级数组* @param int* @return array*/function get_child（$myid）{$a = $newarr = array（）;if（is_array（$this->arr））{foreach（$this->arr as $id => $a）{if（$a["parentid"] == $myid） $newarr[$id] = $a;}}return $newarr ? $newarr : false;} /*** 得到当前位置数组* @param int* @return array*/function get_pos（$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 * ------------------------------------- * @author abc * @param $myid 表示获得这个ID下的所有子级 * @param $str 生成树形结构基本代码, 例如: "<option value=$id $select>$spacer$name</option>" * @param $sid 被选中的ID, 比如在做树形下拉框的时候需要用到 * @param $adds * @param $str_group */function get_tree（$myid, $str, $sid = 0, $adds = "", $str_group = ""）{$number=1;$child = $this->get_child（$myid）;if（is_array（$child）） {$total = count（$child）;foreach（$child as $id=>$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 = $id==$sid ? "selected" : "";@extract（$a）;$parentid == 0 && $str_group ? eval（"$nstr = "$str_group";"） : eval（"$nstr = "$str";"）;$this->ret .= $nstr;$this->get_tree（$id, $str, $sid, $adds.$k." ",$str_group）;$number++;}}return $this->ret;} /*** 同上一方法类似,但允许多选*/function get_tree_multi（$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 $this->ret;} function have（$list,$item）{return（strpos（",,".$list.",",",".$item.","））;} /** +------------------------------------------------ * 格式化数组 +------------------------------------------------ * @author abc +------------------------------------------------ */function getArray（$myid=0, $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 : "";@extract（$a）;$a["name"] = $spacer." ".$a["name"];$this->ret[$a["id"]] = $a;$fd = $adds.$k." ";$this->getArray（$id, $sid, $fd）;$number++;}} return $this->ret;}}$data=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"=>""）,8 => array（"id"=>"8","parentid"=>3,"name"=>"三级栏目三"）, 9 => array（"id"=>"9","parentid"=>7,"name"=>"四级分类三"）, ）; $tree = new Tree;$tree->tree（$data）; // 如果使用数组, 请使用 getArray方法 //$tree->getArray（）; // 下拉菜单选项使用 get_tree方法 $html="<select name="tree">"; $str = "<option value=$id $select>$spacer$name</option>"; $html .= $tree->get_tree（0,$str,-1）."</select>"; echo $html; ?>