localStorage存值取值以及存取JSON,以及基于html5 localStorage的购物车[转]

localStorage.setItem(“key”,”value”);//存储变量名为key,值为value的变量

localStorage.key = “value”//存储变量名为key,值为value的变量

localStorage.getItem(“key”);//获取存储的变量key的值www.it165.net

localStorage.key;//获取存储的变量key的值

localStorage.removeItem(“key”)//删除变量名为key的存储变量


//以上即为localStorage调用的方法。下面介绍存储JSON对象的方法。
var students =
{
liyang:{name:”liyang”,age:17},

lilei:{name:”lilei”,age:18}

}//要存储的JSON对象

students = JSON.stringify(students);//将JSON对象转化成字符串

localStorage.setItem(“students”,students);//用localStorage保存转化好的的字符串


//上面即可保存JSON对象,接下来我们在要使用的时候再将存储好的students变量取回

var students = localStorage.getItem(“students”);//取回students变量

students = JSON.parse(students);//把字符串转换成JSON对象

//以上即可得到存储的students的JSON对象了


utils = {
setParam : function (name,value){
localStorage.setItem(name,value)
},
getParam : function(name){
return localStorage.getItem(name)
}
}

product={
id:0,
name:””,
num:0,
price:0.00
};
orderdetail={
username:””,
phone:””,
address:””,
zipcode:””,
totalNumber:0,
totalAmount:0.00
}
cart = {
//向购物车中添加商品
addproduct: function (product) {
var ShoppingCart = utils.getParam(“ShoppingCart”);
if (ShoppingCart == null || ShoppingCart == “”) {
//第一次加入商品
var jsonstr = { “productlist”: [{ “id”: product.id, “name”: product.name, “num”: product.num, “price”: product.price}], “totalNumber”: product.num, “totalAmount”: (product.price * product.num) };
utils.setParam(“ShoppingCart”, “‘” + JSON.stringify(jsonstr));
} else {
var jsonstr = JSON.parse(ShoppingCart.substr(1, ShoppingCart.length));
var productlist = jsonstr.productlist;
var result = false;
//查找购物车中是否有该商品
for (var i in productlist) {
if (productlist[i].id == product.id) {
productlist[i].num = parseInt(productlist[i].num) + parseInt(product.num);
result = true;
}
}
if (!result) {
//没有该商品就直接加进去
productlist.push({ “id”: product.id, “name”: product.name, “num”: product.num, “price”: product.price });
}
//重新计算总价
jsonstr.totalNumber = parseInt(jsonstr.totalNumber) + parseInt(product.num);
jsonstr.totalAmount = parseFloat(jsonstr.totalAmount) + (parseInt(product.num) * parseFloat(product.price));
orderdetail.totalNumber = jsonstr.totalNumber;
orderdetail.totalAmount = jsonstr.totalAmount;
//保存购物车
utils.setParam(“ShoppingCart”, “‘” + JSON.stringify(jsonstr));
}
},
//修改给买商品数量
updateproductnum: function (id, num) {
var ShoppingCart = utils.getParam(“ShoppingCart”);
var jsonstr = JSON.parse(ShoppingCart.substr(1, ShoppingCart.length));
var productlist = jsonstr.productlist;

for (var i in productlist) {
if (productlist[i].id == id) {
jsonstr.totalNumber = parseInt(jsonstr.totalNumber) + (parseInt(num) – parseInt(productlist[i].num));
jsonstr.totalAmount = parseFloat(jsonstr.totalAmount) + ((parseInt(num) * parseFloat(productlist[i].price)) – parseInt(productlist[i].num) * parseFloat(productlist[i].price));
productlist[i].num = parseInt(num);
orderdetail.totalNumber = jsonstr.totalNumber;
orderdetail.totalAmount = jsonstr.totalAmount;
utils.setParam(“ShoppingCart”, “‘” + JSON.stringify(jsonstr));
return;
}
}
},
//获取购物车中的所有商品
getproductlist: function () {
var ShoppingCart = utils.getParam(“ShoppingCart”);
var jsonstr = JSON.parse(ShoppingCart.substr(1, ShoppingCart.length));
var productlist = jsonstr.productlist;
orderdetail.totalNumber = jsonstr.totalNumber;
orderdetail.totalAmount = jsonstr.totalAmount;
return productlist;
},
//判断购物车中是否存在商品
existproduct: function (id) {
var result = false;
var ShoppingCart = utils.getParam(“ShoppingCart”);
if (ShoppingCart != null) {
var jsonstr = JSON.parse(ShoppingCart.substr(1, ShoppingCart.length));
var productlist = jsonstr.productlist;
for (var i in productlist) {
if (productlist[i].id == id) {
result = true;
}
}
}
return result;
},
//删除购物车中商品
deleteproduct: function (id) {
var ShoppingCart = utils.getParam(“ShoppingCart”);
var jsonstr = JSON.parse(ShoppingCart.substr(1, ShoppingCart.length));
var productlist = jsonstr.productlist;
var list = [];
for (var i in productlist) {
if (productlist[i].id == id) {
jsonstr.totalNumber = parseInt(jsonstr.totalNumber) – parseInt(productlist[i].num);
jsonstr.totalAmount = parseFloat(jsonstr.totalAmount) – parseInt(productlist[i].num) * parseFloat(productlist[i].price);
} else {
list.push(productlist[i]);
}
}
jsonstr.productlist = list;
orderdetail.totalNumber = jsonstr.totalNumber;
orderdetail.totalAmount = jsonstr.totalAmount;
utils.setParam(“ShoppingCart”, “‘” + JSON.stringify(jsonstr));
}
};

———–
//上面的基于html5 localStorage的购物车JS脚本使用方法
var product =
{
‘id’: id, //属性名用引号括起来,属性间由逗号隔开
‘name’: ‘hhh’,
‘num’:jq(‘#text-4’).val(),
‘price’:199.9
};
//商品加入到购物车
cart.addproduct(product);
var productlist=cart.getproductlist();//取出购物车商品
alert(”, ‘商品:’+productlist[0].id+’ ‘+productlist[0].name+’ ‘+productlist[0].num+’ ‘+productlist[0].price, ‘确定’);