gpt4 book ai didi

javascript - 在本地存储中保存动态创建的列表框

转载 作者:行者123 更新时间:2023-11-28 00:00:54 25 4
gpt4 key购买 nike

我制作了一张谷歌地图,在“源”列表框中列出了可能的映射位置。您可以选择任意多个,然后按一个按钮,它们就会转到下一个列表框。一旦你按下“ map 位置”按钮,它们都会被映射。我已经尝试并失败了,以获取动态列出的所需位置以使用本地存储进行保存和调用,因此当用户返回页面时,他们最后的位置仍然存在。这对于使用 ipad 和其他平板电脑的用户来说很重要。有人可以帮助将动态创建的选项保存在列表框中吗?我已经阅读了很多关于本地存储的文章,但这似乎是一个独特的情况。

<!DOCTYPE html>
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<script type='text/javascript' src='http://code.jquery.com/jquery-1.9.1.js'></script>
<script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false"></script>

<style type='text/css'>
#map-canvas { width:940px; height:625px; }
.layer-wizard-search-label { font-family: sans-serif };

</style>
<script type='text/javascript'>//<![CDATA[
var map;
var layer_0;
var destSelect;
var filter;

function initialize() {
map = new google.maps.Map(document.getElementById('map-canvas'), {
center: new google.maps.LatLng(47.724544549099676, -100.43701171875),
scaleControl: true,
zoom: 7, //zoom
zoomControl: true,
zoomControlOptions: {
style: google.maps.ZoomControlStyle.LARGE,
position: google.maps.ControlPosition.TOP_LEFT},
mapTypeId: google.maps.MapTypeId.ROADMAP //the map style
});

layer_0 = new google.maps.FusionTablesLayer({
map: map
});
///Storage
filter = document.getElementById("filter");
destSelect = document.getElementById("destSelect");

if (localStorage.locations)
destSelect.value = localStorage.locations;

}

function saveChoice() {
localStorage.locations=destSelect.value;
console.log + localStorage.locations;
}
///
function changeMap_0() {
var query={
select: "'geometry'",
from: "1xDlCWWj4WMCadzaua5bBss3UNLprGCnsS3H4vt0"
},
values=[],
options=document.getElementById('destSelect').options;

if(!options.length){
//no options added, remove the layer
//and leave the function
layer_0.setMap(null);
return;
}

//collect the values
for(var i =0;i<options.length;++i){
values.push(options[i].value.replace(/'/g, "\\'"));
}
//create where-clause
query.where="'Well Name' IN('"+values.join("','")+"')";

//set the options
layer_0.setOptions({query:query,map:map});
}
function listboxMoveacross(sourceID, destID) {
var src = document.getElementById(sourceID);
var dest = document.getElementById(destID);

for(var count=0; count < src.options.length; count++) {

if(src.options[count].selected == true) {
var option = src.options[count];
var newOption = document.createElement("option");
newOption.value = option.value;
newOption.text = option.text;
newOption.selected = true;
try {
dest.add(newOption, null); //Standard
src.remove(count, null);
}catch(error) {
dest.add(newOption); // IE only
src.remove(count);
}
count--;
}
}
}
google.maps.event.addDomListener(window, 'load', initialize)
</script>


</head>
<body>
<div id="map-canvas"></div>
<table>
<tbody>
<tr>
<td>
<select id="filter" multiple="1">
<option value="101 FEDERAL 21X-24">101 FEDERAL 21X-24</option>
<option value="13 MILE SWD 1">13 MILE SWD 1</option>
<option value="2-BRENDEN 9-33 1-M">2-BRENDEN 9-33 1-M</option>
<option value="20002 JV-P AGATE 1">20002 JV-P AGATE 1</option>
<option value="20002 JV-P AGATE 2">20002 JV-P AGATE 2</option>
</select>

</td>
<td>
<button onclick="listboxMoveacross('filter', 'destSelect');">&gt;&gt;</button> <br>
<button onclick="listboxMoveacross('destSelect', 'filter');">&lt;&lt;</button>
</td>
<td>
<select id="destSelect" size="10" multiple="" onchange="saveChoice()">
</select>
</td>
</tr>

</tbody>
</table>
<button id="mapbutton" onClick="changeMap_0(map);">Map Locations</button>
</body>
</html>

最佳答案

您有两个 listboxMoveacross() 实例 - 为什么?正如@Anto Jurković 评论的那样,onchange 不会发生任何事情。相反

  1. 每次修改时保存destSelect中的所有项目
  2. initialize() 上加载列表,将它们添加到 destSelect 并将它们从 filter 中删除。

保存到存储,在你的 listboxMoveacross() 中调用它:

function saveToStorage() {
var destSelect=document.getElementById("destSelect");
for (var i=0;i<destSelect.length;i++) {
localStorage.setItem('option_'+i, destSelect.options[i].text);
}
}

initalize() 中检索存储的选项并从 filter 中删除存储的选项:

function loadFromStorage() {
var destSelect=document.getElementById("destSelect");
var filter = document.getElementById("filter");
var filterOut = [];
for (var i=0;i<filter.length;i++) {
var storedOption=localStorage.getItem('option_'+i);
if (storedOption != 'null' && storedOption != null) {
var option = document.createElement('option');
option.value = storedOption;
option.innerHTML = storedOption;
destSelect.appendChild(option);
filterOut.push(option);
}
}
//remove stored options from filter
for (var i=filter.length;i>=0;i--) {
for (var t=0;t<filterOut.length;t++) {
if (filter.options[i]!=undefined) {
if (filter.options[i].text.localeCompare(filterOut[t].text)==0) {
filter.removeChild(filter[i]);
}
}
}
}
}

请参阅上面的代码和我的添加 -> http://jsfiddle.net/3AHwz/ destSelect 添加一些值,然后重新加载。

关于javascript - 在本地存储中保存动态创建的列表框,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/21440605/

25 4 0
Copyright 2021 - 2024 cfsdn All Rights Reserved 蜀ICP备2022000587号
广告合作:1813099741@qq.com 6ren.com