/**

*设置带有过期时间的localStorage

*@key，localStorage的关键字

*@v,localStorage的key的值

*@exp,localStorage过期时间，单位毫秒

*/

function set(key, v, exp){

var curTime = new Date().getTime();

try{

localStorage.setItem( key, JSON.stringify({data:v, curtime:curTime, exp:exp}) );

}

catch(e){

console.log("set localStorage failed:"+e);

}

}

/**

*获取带有过期时间的localStorage的值

*@key，localStorage的关键字

*/

function get(key){

try{

var data = localStorage.getItem(key);

}

catch(e){

console.log("get localStorage failed:"+e);

}

var dataObj = JSON.parse(data);

if(new Date().getTime() - dataObj.curtime > dataObj.exp){

console.log("expires:timeout");

}

else{

console.log("data="+dataObj.data);

}

}

set('good', 'luck', 5000);

get('good');

这是我的，不过将js重新放在了别的目录下，所以你要用的话，改下目录

/**

*将图片以canvas的形式保存在localstorage中

*@key 图片名称

*@src 图片相对地址

*/

function setImg(key, src){

var img = document.createElement('img');

//图片加载完成时触发回调函数

img.addEventListener('load', function(){

var imgCanvas = document.createElement('canvas'),

imgContext = imgCanvas.getContext('2d');

imgCanvas.width = this.width;

imgCanvas.height = this.height;

//渲染图片到canvas中

imgContext.drawImage(this, 0, 0, this.width, this.height);

//用data url的形式取出

var imgAsDataURL = imgCanvas.toDataURL('image/png');

//保存到本地存储中

try{

localStorage.setItem(key, imgAsDataURL);

}

catch(e){

console.log("storage failed:" + e);

}

}, false);

}

/**

*从本地取得图片

*/

function getImg(key){

var srcStr = localStorage.getItem(key);

var imgObj = document.createElement('img');

imgObj.src = srcStr;

document.body.appendChild(imgObj);

}

setImg('img1', 'src/img/doll.jpg');

getImg('img1');