站長(zhǎng)資訊網(wǎng)web存儲(chǔ)，一個(gè)比cookie更好的本地存儲(chǔ)方式
localStorage和sessionStorage
localStorage-沒有時(shí)間限制的數(shù)據(jù)存儲(chǔ)
sessionStorage-針對(duì)一個(gè)session的數(shù)據(jù)存儲(chǔ)
//是否支持if(typeof(Storage)!=="undefined") {// 是的! 支持 localStorage sessionStorage 對(duì)象!// 一些代碼.....} else {// 抱歉! 不支持 web 存儲(chǔ)。}
localStorage對(duì)象
localStorage對(duì)象存儲(chǔ)的數(shù)據(jù)沒有時(shí)間限制
localStorage.sitename="小南瓜"; document.getElementById("result").innerHTML="網(wǎng)站名：" + localStorage.sitename;
不管是 localStorage，還是 sessionStorage，可使用的API都相同，常用的有如下幾個(gè)（以localStorage為例）：
保存數(shù)據(jù)：localStorage.setItem(key,value); 讀取數(shù)據(jù)：localStorage.getItem(key); 刪除單個(gè)數(shù)據(jù)：localStorage.removeItem(key); 刪除所有數(shù)據(jù)：localStorage.clear(); 得到某個(gè)索引的key：localStorage.key(index);
提示：鍵/值對(duì)通常以字符串存儲(chǔ)，你可以按自己的需要轉(zhuǎn)換該格式。
if(typeof(Storage)!=="undefined") { if (localStorage.clickcount) { localStorage.clickcount=Number(localStorage.clickcount)+1; } else { localStorage.clickcount=1; } document.getElementById("result").innerHTML=" 你已經(jīng)點(diǎn)擊了按鈕 " + localStorage.clickcount + " 次 "; } else { document.getElementById("result").innerHTML="對(duì)不起，您的瀏覽器不支持 web 存儲(chǔ)。"; }
sessionStorage對(duì)象
sessionStorage針對(duì)一個(gè)session進(jìn)行數(shù)據(jù)存儲(chǔ)。當(dāng)用戶關(guān)閉瀏覽器窗口后，數(shù)據(jù)會(huì)被刪除
if(typeof(Storage)!=="undefined") { if (sessionStorage.clickcount) { sessionStorage.clickcount=Number(sessionStorage.clickcount)+1; } else { sessionStorage.clickcount=1; } document.getElementById("result").innerHTML="在這個(gè)會(huì)話中你已經(jīng)點(diǎn)擊了該按鈕 " + sessionStorage.clickcount + " 次 "; } else { document.getElementById("result").innerHTML="抱歉，您的瀏覽器不支持 web 存儲(chǔ)"; }
簡(jiǎn)單的網(wǎng)站列表程序
<div style="border: 2px dashed #ccc;width:320px;text-align:center;"> <label for="sitename">網(wǎng)站名(key)：</label> <input type="text" id="sitename" name="sitename" class="text"/> <br/> <label for="siteurl">網(wǎng) 址(value)：</label> <input type="text" id="siteurl" name="siteurl"/> <br/> <input type="button" onclick="save()" value="新增記錄"/> <hr/> <label for="search_phone">輸入網(wǎng)站名：</label> <input type="text" id="search_site" name="search_site"/> <input type="button" onclick="find()" value="查找網(wǎng)站"/> <p id="find_result"><br/></p> </div> <br/> <div id="list"> </div> <script>// 載入所有存儲(chǔ)在localStorage的數(shù)據(jù) loadAll(); //保存數(shù)據(jù) function save(){ var siteurl = document.getElementById("siteurl").value; var sitename = document.getElementById("sitename").value; localStorage.setItem(sitename, siteurl); alert("添加成功"); }//查找數(shù)據(jù) function find(){ var search_site = document.getElementById("search_site").value; var sitename = localStorage.getItem(search_site); var find_result = document.getElementById("find_result"); find_result.innerHTML = search_site + "的網(wǎng)址是：" + sitename; }//將所有存儲(chǔ)在localStorage中的對(duì)象提取出來，并展現(xiàn)到界面上function loadAll(){ var list = document.getElementById("list"); if(localStorage.length>0){ var result = "<table border='1'>"; result += "<tr><td>網(wǎng)站名</td><td>網(wǎng)址</td></tr>"; for(var i=0;i<localStorage.length;i++){ var sitename = localStorage.key(i); var siteurl = localStorage.getItem(sitename); result += "<tr><td>"+sitename+"</td><td>"+siteurl+"</td></tr>"; } result += "</table>"; list.innerHTML = result; }else{ list.innerHTML = "數(shù)據(jù)為空……"; } } </script>
運(yùn)行結(jié)果：
JSON.stringify
存儲(chǔ)對(duì)象數(shù)據(jù)，將對(duì)象轉(zhuǎn)換為字符串
var site = new Object; ...var str = JSON.stringify(site); // 將對(duì)象轉(zhuǎn)換為字符串
JSON.parse
將字符串轉(zhuǎn)換為JSON對(duì)象
<div style="border: 2px dashed #ccc;width:320px;text-align:center;"><label for="keyname">別名(key):</label> <input type="text" id="keyname" name="keyname" class="text"/> <br/> <label for="sitename">網(wǎng)站名：</label> <input type="text" id="sitename" name="sitename" class="text"/> <br/> <label for="siteurl">網(wǎng) 址：</label> <input type="text" id="siteurl" name="siteurl"/> <br/> <input type="button" onclick="save()" value="新增記錄"/> <hr/> <label for="search_phone">輸入別名(key)：</label> <input type="text" id="search_site" name="search_site"/> <input type="button" onclick="find()" value="查找網(wǎng)站"/> <p id="find_result"><br/></p> </div> <br/> <div id="list"> </div> <script>//保存數(shù)據(jù) function save(){ var site = new Object; site.keyname = document.getElementById("keyname").value; site.sitename = document.getElementById("sitename").value; site.siteurl = document.getElementById("siteurl").value;var str = JSON.stringify(site); // 將對(duì)象轉(zhuǎn)換為字符串 localStorage.setItem(site.keyname,str); alert("保存成功"); } //查找數(shù)據(jù) function find(){ var search_site = document.getElementById("search_site").value; var str = localStorage.getItem(search_site); var find_result = document.getElementById("find_result");var site = JSON.parse(str); find_result.innerHTML = search_site + "的網(wǎng)站名是：" + site.sitename + "，網(wǎng)址是：" + site.siteurl; } //將所有存儲(chǔ)在localStorage中的對(duì)象提取出來，并展現(xiàn)到界面上// 確保存儲(chǔ)的 keyname 對(duì)應(yīng)的值為轉(zhuǎn)換對(duì)象，否則JSON.parse會(huì)報(bào)錯(cuò)function loadAll(){ var list = document.getElementById("list"); if(localStorage.length>0){ var result = "<table border='1'>"; result += "<tr><td>別名</td><td>網(wǎng)站名</td><td>網(wǎng)址</td></tr>"; for(var i=0;i<localStorage.length;i++){ var keyname = localStorage.key(i); var str = localStorage.getItem(keyname); var site = JSON.parse(str); result += "<tr><td>"+site.keyname+"</td><td>"+site.sitename+"</td><td>"+site.siteurl+"</td></tr>"; } result += "</table>"; list.innerHTML = result; }else{ list.innerHTML = "數(shù)據(jù)為空..."; } } </script>
上面是JSON.stringify轉(zhuǎn)換的結(jié)果
下面是JSON.parse轉(zhuǎn)換結(jié)果
