我想在我的所有网页上添加下一个prev函数。
现在：Prev工作正常，接下来就是这样0 =＆gt; 1 =＆gt; 2 =＆gt; 3 =＆gt; 4 =＆gt; 5 =＆gt; 6 =＆gt; 0 =＆gt; 1 ...
PS：我不想显示第0页。我想从第1页开始。
$productArr = ["ac" => ["001" => ["dimension"=>"H: 85 W: 67 D: 72", "price"=>850.00 , "images"=>7],
"002" => ["dimension"=>"H: -- W: -- D: --", "price"=>860.00 , "images"=>7],
"003" => ["dimension"=>"H: 95 W: 71 D: 90", "price"=>890.00 , "images"=>7],
"004" => ["dimension"=>"H: 78 W: 68 D: 78", "price"=>740.00 , "images"=>4],
"005" => ["dimension"=>"H: 102 W: 69 D: 90", "price"=>890.00 , "images"=>7],
"006" => ["dimension"=>"H: 89 W: 80 D: 86", "price"=>1280.00, "images"=>7],
"007" => ["dimension"=>"H: 78 W: 66 D: 66", "price"=>680.00 , "images"=>7],
"008" => ["dimension"=>"H: 80 W: 78 D: 74", "price"=>800.00 , "images"=>7],
"009" => ["dimension"=>"H: 94 W: 64 D: 88", "price"=>790.00 , "images"=>5],
"010" => ["dimension"=>"H: 83 W: 68 D: 72", "price"=>850.00 , "images"=>7],
"011" => ["dimension"=>"H: 70 W: 66 D: 77", "price"=>860.00 , "images"=>7],
"012" => ["dimension"=>"H: 88 W: 84 D: 88", "price"=>1280.00, "images"=>7],
"013" => ["dimension"=>"H: 80 W: 70 D: 84", "price"=>860.00 , "images"=>7],
"014" => ["dimension"=>"H: 82 W: 68 D: 80", "price"=>780.00 , "images"=>7],
"015" => ["dimension"=>"H: 82 W: 72 D: 78", "price"=>890.00 , "images"=>7],
"016" => ["dimension"=>"H: 75 W: 59 D: 47", "price"=>780.00 , "images"=>7],
"017" => ["dimension"=>"H: 90 W: 77 D: 83", "price"=>1280.00, "images"=>7],
"018" => ["dimension"=>"H: -- W: -- D: --", "price"=>680.00 , "images"=>5],
"020" => ["dimension"=>"H: 74 W: 63 D: 89", "price"=>860.00 , "images"=>4]]];
$catCode = isset($_GET["cat"]) ? $_GET["cat"] : "ac";
$page = isset($_GET["page"]) ? $_GET["page"] : 1;
foreach ($productArr[$catCode] as $imgNumber => $productDetail) {
array_push($arr, $imgNumber);
$imgNumber = $arr;
// index[18] change to 20
}
$total = count($arr);
// limit the number of images shown
$limit = 3;
//calculate the total number of pages
$totalPages = ceil($total / $limit);
$nextPage = ($page + 1) % $totalPages ;
$prevPage = ($page == 1) ? $totalPages : $page - 1;
echo"<a href='http://localhost/collectionPage.php?cat=$catCode&page={$prevPage}' ><img class='img-responsive pull-left' src='images/arrow_left.jpg'> </a>";
echo"<a href='http://localhost/collectionPage.php?cat=$catCode&page={$nextPage}' ><img class='img-responsive pull-right' src='images/arrow_right.jpg'> </a>";
答案 0 :(得分：2)
这是因为这一行
$nextPage = ($page + 1) % 8;
将totalpage + 1;
答案 1 :(得分：1)
你可以这样做（更具可读性）：
$prevPage = ($page == 1) ? $totalPages : $page - 1;
$nextPage = ($page == $totalPages) ? 1 : $page + 1;
或者这样：
$prevPage = ($page + $totalPages - 2) % $totalPages + 1;
$nextPage = $page % $totalPages + 1;
上一页更棘手，因为余数开始计算负值（-2，-1,0,1,2 ......）的另一种方式 - 因此+ $totalPages
我还建议添加一个检查当前页面是否在限制范围内的条件 - 用户可以发送任何内容。
$page = isset($_GET["page"]) ? intval($_GET["page"]) : 1;
if ($page > $totalPages || $page < 1) { $page = 1; }
答案 2 :(得分：0)
查看下面的脚本。这为您提供了完整的解决方案。
// find out how many rows are in the table
$sql = "SELECT COUNT(*) FROM numbers";
$result = mysql_query($sql, $conn) or trigger_error("SQL", E_USER_ERROR);
$r = mysql_fetch_row($result);
$numrows = $r[0];
// number of rows to show per page
$rowsperpage = 10;
// find out total pages
$totalpages = ceil($numrows / $rowsperpage);
// get the current page or set a default
if (isset($_GET['currentpage']) && is_numeric($_GET['currentpage'])) {
// cast var as int
$currentpage = (int) $_GET['currentpage'];
} else {
// default page num
$currentpage = 1;
} // end if
// if current page is greater than total pages...
if ($currentpage > $totalpages) {
// set current page to last page
$currentpage = $totalpages;
} // end if
// if current page is less than first page...
if ($currentpage < 1) {
// set current page to first page
$currentpage = 1;
} // end if
// the offset of the list, based on current page
$offset = ($currentpage - 1) * $rowsperpage;
// get the info from the db
$sql = "SELECT id, number FROM numbers LIMIT $offset, $rowsperpage";
$result = mysql_query($sql, $conn) or trigger_error("SQL", E_USER_ERROR);
// while there are rows to be fetched...
while ($list = mysql_fetch_assoc($result)) {
// echo data
echo $list['id'] . " : " . $list['number'] . "<br />";
} // end while
/****** build the pagination links ******/
// range of num links to show
$range = 3;
// if not on page 1, don't show back links
if ($currentpage > 1) {
// show << link to go back to page 1
echo " <a href='{$_SERVER['PHP_SELF']}?currentpage=1'><<</a> ";
// get previous page num
$prevpage = $currentpage - 1;
// show < link to go back to 1 page
echo " <a href='{$_SERVER['PHP_SELF']}?currentpage=$prevpage'><</a> ";
} // end if
// loop to show links to range of pages around current page
for ($x = ($currentpage - $range); $x < (($currentpage + $range) + 1); $x++) {
// if it's a valid page number...
if (($x > 0) && ($x <= $totalpages)) {
// if we're on current page...
if ($x == $currentpage) {
// 'highlight' it but don't make a link
echo " [<b>$x</b>] ";
// if not current page...
} else {
// make it a link
echo " <a href='{$_SERVER['PHP_SELF']}?currentpage=$x'>$x</a> ";
} // end else
} // end if
} // end for
// if not on last page, show forward and last page links
if ($currentpage != $totalpages) {
// get next page
$nextpage = $currentpage + 1;
// echo forward link for next page
echo " <a href='{$_SERVER['PHP_SELF']}?currentpage=$nextpage'>></a> ";
// echo forward link for lastpage
echo " <a href='{$_SERVER['PHP_SELF']}?currentpage=$totalpages'>>></a> ";
} // end if
/****** end build pagination links ******/
?>