Question

我对生成的多级菜单有疑问。我希望每个菜单级别选择另一种颜色（li class = menucolor）。但是，我设法只做了第一级和第二级。我无法将第二级与第三级分开。请帮忙。

SQL：

CREATE TABLE IF NOT EXISTS `menu` (
`id` int(11) NOT NULL auto_increment,
`id_parent` int(11) NOT NULL default '0',
`link` varchar(255) NOT NULL,
`order` int(11) NOT NULL default '0',
`title` varchar(255) collate utf8_polish_ci NOT NULL default '',
PRIMARY KEY  (`id`)
);


INSERT INTO `menu` (`id`, `id_parent`, `link`, `order`, `title`) VALUES
(1, 0, index.php, 3, 'Index'),
(3, 1, link1.php, 1, 'Art1'),
(4, 1, link2.php, 2, 'Art2'),
(5, 4, link2.php, 6, 'Other art'),
(6, 4, link2.php, 1, 'Art AAA'),
(7, 4, link2.php, 1, 'Art BBB'),
(8, 4, link2.php, 1, 'Art CCC'),

AND CODE：

<ul id="menu_left">
<?php
$menuArray = array();
$query = mysql_query('  select id, id_parent, link, order, title
                        from menu
                        order by order asc
              ');

while($row = mysql_fetch_array($query))
{
  $menuArray[] = array( 'id'           => $row['id'],
                        'id_parent'    => $row['id_parent'], 
                        'link'         => $row['link'],
                        'order'        => $row['order'], 
                        'title'        => $row['title']
              );
}

function menu($id)
{
  global $menuArray;
  $hasChildren = false;
  $resultArray = array();

  if (empty($menuArray))
  {
    return;
  }

  foreach ($menuArray as $value)
  {
    if ($value['id_parent'] == $id)
    {
      $resultArray[] = $value;

    }
  }

  foreach ($resultArray as $value)
  {
    if ($hasChildren === false)
    {
      $hasChildren = true;
      if ($value['id_parent'] == 0)
      {
      $j++
        ?>
        <!-- ul first -->
        <?php
      }
      else
      {
        ?>
       <!-- <ul> -->
        <?php
      }
    }
    if($j=='1') {
    echo '<li class="menucolor0">';
    }
    elseif($j!='1') {
    echo '<li class="menucolor1">';
    }
    ?>
    <a href=<?php echo $value['link']; ?>"><?php echo $value['title']; ?></a> 
    <?php
    menu($value['id']);
    ?> 
    </li>
    <?php
  }
  if ($hasChildren === true)
  {
  <!-- </ul> -->
  }
}

menu(0); 
?>    
        </ul>

Answer 1

if($j=='1') {
echo '<li class="menucolor0">';
}
elseif($j!='1') {
echo '<li class="menucolor1">';
}

你只允许两种情况，要么等于1，要么不等。

switch ($j) {
case 1:
    echo  '<li class="menucolor0">';
    break;
case 2:
     echo '<li class="menucolor1">';
    break;
case 3:
     echo '<li class="menucolor2">';
     break;
default:
     echo '<li class="menucolor0">;
     break;

}

Answer 2

对此的任何直接解决方案都会非常缓慢，我建议您更新表格：

<?php

$db = new PDO('mysql:dbname=databasename', 'username', 'password',
    array(PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES utf8"));

$db->prepare('ALTER TABLE `menu` ADD COLUMN `level` TINYINT NOT NULL DEFAULT 0;')->execute();

$db->prepare('UPDATE `menu` SET `level` = 1 WHERE `id_parent` = 0;')->execute();

$select = $db->prepare('SELECT `id` FROM `menu` WHERE `level` = :level');
$update = $db->prepare('UPDATE `menu` SET `level` = :level WHERE `id_parent` = :parent');

for( $i = 1; $i < 100; $i++ ) {
    $select->execute(array('level' => $i));
    while( ($current = $select->fetch(PDO::FETCH_COLUMN)) !== false )
        $update->execute(array('level' => $i + 1, 'parent' => $current));
}

以下是按所需顺序显示菜单的方法：

<?php
// connect to database using PDO
$db = new PDO('mysql:dbname=databasename', 'username', 'password',
    array(PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES utf8"));


function createsubmenu( $item )
{
    global $db;
// prepare a query to get subitems of the current $item (those with parent = $item)
    $subsel = $db->prepare('SELECT id, link, title, level  FROM menu WHERE id_parent = :parent ORDER BY `order`');
// run the query
    $subsel->execute(array('parent' => $item));
    $text = '';
// fetch one row at a time, when no more rows are available $i
// will be false and while ends
    while( ($i = $subsel->fetch(PDO::FETCH_OBJ)) !== false ) {
// generate code for the current $item
// will recursively call createsubmenu to add possibly existing subitems
        $text .= '<li class="menucolor' . ($i->level - 1) . '">'
            .'<a href="' . htmlspecialchars($i->link) . '">' . htmlspecialchars($i->title) . '</a>'
            . createsubmenu($i->id) . '</li>';
    }
// there were no items for the current call
    if( $text == '' )
        return '';
// items were found, wrap them in an unordered list
    return '<ul>' . $text . '</ul>';
}

// call the function for toplevel items (the ones having parent 0)
echo createsubmenu(0);

不要忘记在两个脚本中替换databasename，username和password

生成多级菜单

2 个答案: