我正在使用来自 w3.js( https://www.w3schools.com/howto/howto_js_sort_table.asp ) 的表格排序器。
此外，我使用 setTimeout 来每分钟刷新页面以更新数据。
我想保留刷新页面后的排序结果。
我知道有一种方法是使用sessionStorage，但是不知道怎么用。
谁能给我一些提示？
最佳答案
下面是 SortTable 中示例的更新片段.我们使用浏览器cookies来恢复上一次的排序信息，主要是排序的列和方向。 W3school 中还有另一个示例，我从中获得了 cookie 处理 ( Cookies )。由于跨源政策，下面的代码片段在网站上不起作用。当然，它还需要一些重构，但这是一个开始。
<!DOCTYPE html>
<html>
<head>
<title>Sort a HTML Table Alphabetically</title>
<style>
table {
border-spacing: 0;
width: 100%;
border: 1px solid #ddd;
}
th {
cursor: pointer;
}
th, td {
text-align: left;
padding: 16px;
}
tr:nth-child(even) {
background-color: #f2f2f2
}
</style>
</head>
<body onload="checkCookie();">
<p><strong>Click the headers to sort the table.</strong></p>
<p>The first time you click, the sorting direction is ascending (A to Z).</p>
<p>Click again, and the sorting direction will be descending (Z to A):</p>
<table id="myTable">
<tr>
<!--When a header is clicked, run the sortTable function, with a parameter, 0 for sorting by names, 1 for sorting by country:-->
<th onclick="sortTable(0)">Name</th>
<th onclick="sortTable(1)">Country</th>
</tr>
<tr>
<td>Berglunds snabbkop</td>
<td>Sweden</td>
</tr>
<tr>
<td>North/South</td>
<td>UK</td>
</tr>
<tr>
<td>Alfreds Futterkiste</td>
<td>Germany</td>
</tr>
<tr>
<td>Koniglich Essen</td>
<td>Germany</td>
</tr>
<tr>
<td>Magazzini Alimentari Riuniti</td>
<td>Italy</td>
</tr>
<tr>
<td>Paris specialites</td>
<td>France</td>
</tr>
<tr>
<td>Island Trading</td>
<td>UK</td>
</tr>
<tr>
<td>Laughing Bacchus Winecellars</td>
<td>Canada</td>
</tr>
</table>
<script>
function sortTable(n, dir) {
var table, rows, switching, i, x, y, shouldSwitch, dir, switchcount = 0;
table = document.getElementById("myTable");
switching = true;
//Set the sorting direction to ascending:
!dir && (dir = "asc");
/*Make a loop that will continue until
no switching has been done:*/
while (switching) {
//start by saying: no switching is done:
switching = false;
rows = table.getElementsByTagName("TR");
/*Loop through all table rows (except the
first, which contains table headers):*/
for (i = 1; i < (rows.length - 1); i++) {
//start by saying there should be no switching:
shouldSwitch = false;
/*Get the two elements you want to compare,
one from current row and one from the next:*/
x = rows[i].getElementsByTagName("TD")[n];
y = rows[i + 1].getElementsByTagName("TD")[n];
/*check if the two rows should switch place,
based on the direction, asc or desc:*/
if (dir == "asc") {
if (x.innerHTML.toLowerCase() > y.innerHTML.toLowerCase()) {
//if so, mark as a switch and break the loop:
shouldSwitch= true;
break;
}
} else if (dir == "desc") {
if (x.innerHTML.toLowerCase() < y.innerHTML.toLowerCase()) {
//if so, mark as a switch and break the loop:
shouldSwitch= true;
break;
}
}
}
if (shouldSwitch) {
/*If a switch has been marked, make the switch
and mark that a switch has been done:*/
rows[i].parentNode.insertBefore(rows[i + 1], rows[i]);
switching = true;
//Each time a switch is done, increase this count by 1:
switchcount ++;
} else {
/*If no switching has been done AND the direction is "asc",
set the direction to "desc" and run the while loop again.*/
if (switchcount == 0 && dir == "asc") {
dir = "desc";
switching = true;
}
}
}
setCookie("sortBy", n, 30);
setCookie("sortByDir", dir);
}
function setCookie(cname,cvalue,exdays) {
var d = new Date();
d.setTime(d.getTime() + (exdays*24*60*60*1000));
var expires = "expires=" + d.toGMTString();
document.cookie = cname + "=" + cvalue + ";" + expires + ";path=/";
}
function getCookie(cname) {
var name = cname + "=";
var decodedCookie = decodeURIComponent(document.cookie);
var ca = decodedCookie.split(';');
for(var i = 0; i < ca.length; i++) {
var c = ca[i];
while (c.charAt(0) == ' ') {
c = c.substring(1);
}
if (c.indexOf(name) == 0) {
return c.substring(name.length, c.length);
}
}
return "";
}
function checkCookie() {
var sortBy=getCookie("sortBy");
if (sortBy != "") {
sortTable(parseInt(sortBy), getCookie("sortByDir"));
}
}
</script>
</body>
</html>编辑: 另一个使用 sessionStorage 的片段
<!DOCTYPE html>
<html>
<head>
<title>Sort a HTML Table Alphabetically</title>
<style>
table {
border-spacing: 0;
width: 100%;
border: 1px solid #ddd;
}
th {
cursor: pointer;
}
th, td {
text-align: left;
padding: 16px;
}
tr:nth-child(even) {
background-color: #f2f2f2
}
</style>
</head>
<body onload="checkStrorage();">
<p><strong>Click the headers to sort the table.</strong></p>
<p>The first time you click, the sorting direction is ascending (A to Z).</p>
<p>Click again, and the sorting direction will be descending (Z to A):</p>
<table id="myTable">
<tr>
<!--When a header is clicked, run the sortTable function, with a parameter, 0 for sorting by names, 1 for sorting by country:-->
<th onclick="sortTable(0)">Name</th>
<th onclick="sortTable(1)">Country</th>
</tr>
<tr>
<td>Berglunds snabbkop</td>
<td>Sweden</td>
</tr>
<tr>
<td>North/South</td>
<td>UK</td>
</tr>
<tr>
<td>Alfreds Futterkiste</td>
<td>Germany</td>
</tr>
<tr>
<td>Koniglich Essen</td>
<td>Germany</td>
</tr>
<tr>
<td>Magazzini Alimentari Riuniti</td>
<td>Italy</td>
</tr>
<tr>
<td>Paris specialites</td>
<td>France</td>
</tr>
<tr>
<td>Island Trading</td>
<td>UK</td>
</tr>
<tr>
<td>Laughing Bacchus Winecellars</td>
<td>Canada</td>
</tr>
</table>
<script>
function sortTable(n, dir) {
var table, rows, switching, i, x, y, shouldSwitch, dir, switchcount = 0;
table = document.getElementById("myTable");
switching = true;
//Set the sorting direction to ascending:
!dir && (dir = "asc");
/*Make a loop that will continue until
no switching has been done:*/
while (switching) {
//start by saying: no switching is done:
switching = false;
rows = table.getElementsByTagName("TR");
/*Loop through all table rows (except the
first, which contains table headers):*/
for (i = 1; i < (rows.length - 1); i++) {
//start by saying there should be no switching:
shouldSwitch = false;
/*Get the two elements you want to compare,
one from current row and one from the next:*/
x = rows[i].getElementsByTagName("TD")[n];
y = rows[i + 1].getElementsByTagName("TD")[n];
/*check if the two rows should switch place,
based on the direction, asc or desc:*/
if (dir == "asc") {
if (x.innerHTML.toLowerCase() > y.innerHTML.toLowerCase()) {
//if so, mark as a switch and break the loop:
shouldSwitch= true;
break;
}
} else if (dir == "desc") {
if (x.innerHTML.toLowerCase() < y.innerHTML.toLowerCase()) {
//if so, mark as a switch and break the loop:
shouldSwitch= true;
break;
}
}
}
if (shouldSwitch) {
/*If a switch has been marked, make the switch
and mark that a switch has been done:*/
rows[i].parentNode.insertBefore(rows[i + 1], rows[i]);
switching = true;
//Each time a switch is done, increase this count by 1:
switchcount ++;
} else {
/*If no switching has been done AND the direction is "asc",
set the direction to "desc" and run the while loop again.*/
if (switchcount == 0 && dir == "asc") {
dir = "desc";
switching = true;
}
}
}
sessionStorage.setItem('sortBy', n);
sessionStorage.setItem('sortByDir', dir);
}
function checkStrorage() {
var sortBy= sessionStorage.getItem('sortBy');
if (sortBy !== null) {
sortTable(parseInt(sortBy), sessionStorage.getItem('sortByDir'));
}
}
</script>
</body>
</html>关于javascript - 页面刷新后保留表格排序结果？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/47973310/