<!DOCTYPE html>
<html>
<head>
<title>购物车</title>
<meta charset="utf-8" />
<style type="text/css">
h1 {
text-align:center;
}
table {
margin:0 auto;
width:60%;
border:2px solid #aaa;
border-collapse:collapse;
}
table th, table td {
border:2px solid #aaa;
padding:5px;
}
th {
background-color:#eee;
}
</style>
<script type="text/javascript">
//加入购物车=================================================
//调用此函数时传入了this,声明参数来接收它,参数名不能叫this(关键字)
function add_shoppingcart(btn){
//获取按钮的爷爷
var tr = btn.parentNode.parentNode;
//获取tr的所有孩子(tds)
var tds = tr.getElementsByTagName("td");
//获取第1个td的内容(商品名)
var name = tds[0].innerHTML;
//获取第2个td的内容(单价)
var price = tds[1].innerHTML;
//创建一个新的tr,设置内容,追加到tbody下
var newtr = document.createElement("tr");
newtr.innerHTML = '<td>'+name+'</td>'+
'<td>'+price+'</td><td align="center">'+
'<input type="button" value="-" onclick="decrease(this);"/> '+
'<input type="text" size="3" readonly value="1"/> '+
'<input type="button" value="+" onclick="increase(this);"/>'+
'</td>'+
'<td>'+price+'</td>'+
'<td align="center"><input type="button" value="x" onclick="drop(this);"/></td>';//添加删除事件
var tbody = document.getElementById("goods");
tbody.appendChild(newtr);
sum();
}
//加法 数量不能大于库存========================================
function increase(btn){
//获取按钮的父亲
var td2 = btn.parentNode;
//获取td2内的文本框
var text = td2.getElementsByTagName("input")[1];
//获取文本框内值+1后写回文本框
var amount = text.value;
text.value = ++amount;
//获取td2的哥哥td1,从中取出单价
var td1 = td2.parentNode.getElementsByTagName("td")[1];
var price = td1.innerHTML;
//计算金额
var mny = price*amount;
//获取td2的弟弟td3,将金额写回td3
var td3 = td2.parentNode.getElementsByTagName("td")[3];
td3.innerHTML = mny;
sum();
}
//减法 数量不能小于1 =================================================
function decrease(btn){
//获取按钮的父亲td2
var td2 = btn.parentNode;
//获取td2的文本框
var text = td2.getElementsByTagName("input")[1];
//获取文本框的值-1写回文本框
var amount = text.value;
if(amount<1){
text.value = 0;
}
if(amount>0){
text.value = --amount;
}
//获取td2的哥哥td1,从中取回单价
var td1 = td2.parentNode.getElementsByTagName("td")[1];
var price = td1.innerHTML;
//计算金额
var mny = price*amount;
//获取td2的弟弟td3,将金额写入td3
var td3 = td2.parentNode.getElementsByTagName("td")[3];
td3.innerHTML = mny;
sum();
}
//删除tr行,而不是删除tr行中所有td====================
function drop(btn){
var tr = btn.parentNode.parentNode;
var tbody = document.getElementById("goods");
tbody.removeChild(tr);
sum();
}
//计算总金额
function sum() {
//获取购物车内所有的数据行
var tbody =
document.getElementById("goods");
var trs =
tbody.getElementsByTagName("tr");
//遍历这些行
var s = 0;
for(var i=0;i<trs.length;i++) {
//获取每一行下第4个td的内容(金额)
var mny =
trs[i].getElementsByTagName("td")[3].innerHTML;
//累加
s += parseFloat(mny);
}
//将合计值写入合计列(id="total")
var td =
document.getElementById("total");
td.innerHTML = s;
}
</script>
</head>
<body>
<h1>真划算</h1>
<table>
<tr>
<th>商品</th>
<th>单价(元)</th>
<th>颜色</th>
<th>库存</th>
<th>好评率</th>
<th>操作</th>
</tr>
<tr>
<td>罗技M185鼠标</td>
<td>80</td>
<td>黑色</td>
<td>893</td>
<td>98%</td>
<td align="center">
<input type="button" value="加入购物车" onclick="add_shoppingcart(this);"/>
</td>
</tr>
<tr>
<td>微软X470键盘</td>
<td>150</td>
<td>黑色</td>
<td>9028</td>
<td>96%</td>
<td align="center">
<input type="button" value="加入购物车" onclick="add_shoppingcart(this);"/>
</td>
</tr>
<tr>
<td>洛克iphone6手机壳</td>
<td>60</td>
<td>透明</td>
<td>672</td>
<td>99%</td>
<td align="center">
<input type="button" value="加入购物车" onclick="add_shoppingcart(this);"/>
</td>
</tr>
<tr>
<td>蓝牙耳机</td>
<td>100</td>
<td>蓝色</td>
<td>5</td>
<td>95%</td>
<td align="center">
<input type="button" value="加入购物车" onclick="add_shoppingcart(this);"/>
</td>
</tr>
<tr>
<td>金士顿U盘</td>
<td>70</td>
<td>红色</td>
<td>482</td>
<td>100%</td>
<td align="center">
<input type="button" value="加入购物车" onclick="add_shoppingcart(this);"/>
</td>
</tr>
</table>
<h1>购物车</h1>
<table>
<thead>
<tr>
<th>商品</th>
<th>单价(元)</th>
<th>数量</th>
<th>金额(元)</th>
<th>删除</th>
</tr>
</thead>
<tbody id="goods">
</tbody>
<tfoot>
<tr>
<td colspan="3" align="right">总计</td>
<td id="total"></td>
<td></td>
</tr>
</tfoot>
</table>
</body>
</html>
