如下图：
1 <?php 2 3 /** 4 * 栏目记录树 5 * Author 撑一支船蒿 hly 6 * 364077286@qq.com 7 */ 8 class tree 9 { 10 /** 11 * Notes: 递归拿到每个一级栏目的 的子数组 12 * User: hly 13 * Date: 2020/1/7 15:27 14 * @param $category_arr 15 * @param int $pid 16 * @param int $level 17 * @return array 18 */ 19 public function generateTree($category_arr, $pid = 0, $level = 1, $field = array()) 20 { 21 //总记录列表 22 $arr = array(); 23 foreach ($category_arr as & $v) { 24 if ($v[$field['parentid']] == $pid) { 25 //追加字段 记录每个栏目的层级数 26 $v['level'] = $level; 27 //获取此次循环的下一级记录 28 $tem = $this->generateTree($category_arr, $v[$field['categoryid']], $v['level'] + 1, $field); 29 $arr[] = $v; 30 //按顺序追加到总记录中 31 $arr = array_merge($arr, $tem); 32 } 33 } 34 return $arr; 35 } 36 37 /** 38 * Notes: 拼接栏目前隔符 39 * User: hly 40 * Date: 2020/1/7 15:27 41 * @param $level 栏目层级数 42 * @param $is_has_children ：是否有子栏目 43 * @param $is_last 当前栏目是否是同级栏目中的最后一个 44 * @return string 45 */ 46 public function generateStr($level, $is_has_children, $is_last) 47 { 48 $str = ''; 49 for ($i = 1; $i < $level; $i++) { 50 if (!$is_has_children) { 51 if ($is_last) { 52 if ($i == ($level - 1)) { 53 $str .= ' └─'; 54 } else { 55 $str .= ' │'; 56 } 57 //处理一下轮 58 continue; 59 } 60 } 61 62 //不满足上面条件的 拼接这个 63 if ($i == ($level - 1)) { 64 $str .= ' ├─'; 65 } else { 66 $str .= ' │'; 67 } 68 } 69 return $str; 70 } 71 72 /** 73 * Notes: 处理 输出格式数据 74 * User: hly 75 * Date: 2020/1/7 15:27 76 * @param $category_arr 77 * @param $field 定义栏目记录的字段信息 78 * @return array 79 */ 80 public function formatTree($category_arr, $field) 81 { 82 //获取层级数据 83 $tree_data = $this->generateTree($category_arr, 0, 1, $field); 84 //显示顺序结构 85 //var_dump($tree_data); 86 //exit(); 87 88 //收集所有的栏目的 pid 89 $pids = array(); 90 //收集每个同级栏目的 最后一个栏目的 cid 91 $last_cids = array(); 92 foreach ($tree_data as $v) { 93 $pids[] = $v[$field['parentid']]; 94 $last_cids[$v[$field['parentid']]] = $v[$field['categoryid']]; 95 } 96 97 //打印格式 98 foreach ($tree_data as $k => $v) { 99 $is_has_children = in_array($v[$field['categoryid']], $pids) == true ? 1 : 0; 100 $is_last = $last_cids[$v[$field['parentid']]] == $v[$field['categoryid']] ? 1 : 0; 101 //对非第一级栏目 拼接前隔符 $has_children：是否有子栏目 $is_last：当前栏目是否是同级栏目中的最后一个 102 $str = $v['level'] != 1 ? $this->generateStr($v['level'], $is_has_children, $is_last) : ''; 103 $str .= $v[$field['name']]; 104 $tree_data[$k][$field['name']] = $str; 105 } 106 return $tree_data; 107 } 108 } 109 110 $tree = new tree(); 111 112 //测试数据 113 $category_arr = [ 114 //cid => category_id pid => parentid 115 ['cid' => 2, 'name' => '一级栏目1', 'pid' => 0], 116 ['cid' => 4, 'name' => '一级栏目2', 'pid' => 0], 117 ['cid' => 5, 'name' => '一级栏目3', 'pid' => 0], 118 ['cid' => 7, 'name' => '二级栏目1', 'pid' => 2], 119 ['cid' => 8, 'name' => '二级栏目2', 'pid' => 2], 120 ['cid' => 9, 'name' => '三级栏目1', 'pid' => 7], 121 ['cid' => 10, 'name' => '二级栏目4', 'pid' => 5], 122 ['cid' => 11, 'name' => '四级栏目1', 'pid' => 9], 123 ['cid' => 12, 'name' => '五级栏目1', 'pid' => 11], 124 ['cid' => 13, 'name' => '六级栏目1', 'pid' => 12], 125 ['cid' => 14, 'name' => '七级栏目1', 'pid' => 13], 126 ['cid' => 15, 'name' => '五级栏目2', 'pid' => 11], 127 ['cid' => 16, 'name' => '二级栏目5', 'pid' => 2], 128 ['cid' => 17, 'name' => '五级栏目3', 'pid' => 11], 129 ['cid' => 18, 'name' => '三级栏目2', 'pid' => 7], 130 ['cid' => 19, 'name' => '四级栏目2', 'pid' => 9], 131 ['cid' => 20, 'name' => '六级栏目2', 'pid' => 12], 132 ['cid' => 21, 'name' => '四级栏目3', 'pid' => 9], 133 ['cid' => 22, 'name' => '四级栏目4', 'pid' => 9] 134 ]; 135 $field = ['parentid' => 'pid', 'categoryid' => 'cid', 'name' => 'name']; 136 $data = $tree->formatTree($category_arr, $field); 137 138 //打印格式 139 echo '<ul>'; 140 foreach ($data as $k => $v) { 141 echo '<li>' . $v['name'] . '</li>'; 142 } 143 echo '</ul>';
注意：开发环境还需根据您的场景优化下
赞赏码^_^
