localStorage设置过期时间
//设置localStorage
function setLocalStorage(key, value) {
var curtime = new Date().getTime(); // 获取当前时间 ，转换成JSON字符串序列
var valueDate = JSON.stringify({
val: value,
timer: curtime
});
try {
localStorage.setItem(key, valueDate);
} catch(e) {
// 兼容性写法
if(isQuotaExceeded(e)) {
console.log("Error: 本地存储超过限制");
localStorage.clear();
} else {
console.log("Error: 保存到本地存储失败");
}
}
}
function isQuotaExceeded(e) {
var quotaExceeded = false;
if(e) {
if(e.code) {
switch(e.code) {
case 22:
quotaExceeded = true;
break;
case 1014: // Firefox
if(e.name === 'NS_ERROR_DOM_QUOTA_REACHED') {
quotaExceeded = true;
}
break;
}
} else if(e.number === -2147024882) { // IE8
quotaExceeded = true;
}
}
return quotaExceeded;
}
//获取localStorage
function getLocalStorage(key, day=1) {
var exp = 60 * 60 * day; // 一天的秒数
exp = exp*1000;
if(localStorage.getItem(key)) {
var vals = localStorage.getItem(key); // 获取本地存储的值
var dataObj = JSON.parse(vals); // 将字符串转换成JSON对象
// 如果(当前时间 - 存储的元素在创建时候设置的时间) > 过期时间
var isTimed = (new Date().getTime() - dataObj.timer) > exp;
if(isTimed) {
console.log("存储已过期");
localStorage.removeItem(key);
return null;
} else {
var newValue = dataObj.val;
}
return newValue;
} else {
return null;
}
}