<ul class="shopcar_ul"><li class="shopcar_li"><p><label class=""><input type="checkbox" οnclick="onCheck(this)" name="check" sellprice="999.00" qty="1"></label></p></li><li class="shopcar_li"><p><label class=""><input type="checkbox" οnclick="onCheck(this)" name="check" sellprice="999.00" qty="1"></label></p></li><li class="shopcar_li"><p><label class=""><input type="checkbox" οnclick="onCheck(this)" name="check" sellprice="222.00" qty="1"></label></p></li>
</ul>
<div class="pay">
<label><input type="checkbox"><span>全选</span></label>
<div class="pay_right">
<p>
<span>合计：<b class="shop_zjg"></b></span>
</p>
</div>
</div>

//单选var sell;var qty; // 商品数量var jiage; //商品价格var zongjia = 0; //选中商品的总价var check = document.getElementsByName("check");function onCheck(target) {$(this).parent().toggleClass("on");if (target.checked) {$(".car_pay span").addClass("on");sell = target.attributes["sellprice"].nodeValue;qty = target.attributes["qty"].nodeValue;jiage = sell * qty; //当前选中商品的价格zongjia += jiage;//所有选中商品的价格document.getElementsByClassName('shop_zjg')[0].innerHTML = zongjia;} else {sell = target.attributes["sellprice"].nodeValue;qty = target.attributes["qty"].nodeValue;jiage = sell * qty;zongjia -= jiage;if (zongjia < 0) {//如果全选了在取消选中当前商品，这时候总价为0，所以我重新计算一下所有商品的总价var qj = 0;for (var i = 0; i < check.length; i++) {var jg = 0;sell = check[i].attributes["sellprice"].nodeValue;qty = check[i].attributes["qty"].nodeValue;jg = sell * qty;qj += jg;}zongjia = qj - jiage;}document.getElementsByClassName('shop_zjg')[0].innerHTML = zongjia;}for (var i = 0; i < check.length; i++) {//这个是判断是否全选的，用循环判断所有checked是否选中，有一个没被选中就不是全选。if (check[i].checked==true) {$(".pay label span").addClass("on");} else {$(".pay label span").removeClass("on");return;}}}

//全选$(".pay label span").click(function () {var quanjia = 0;if ($(this).hasClass("on")) {$(this).removeClass("on");$("label input").prop("checked", false);$("label").removeClass("on");document.getElementsByClassName('shop_zjg')[0].innerHTML = 0;} else {$(this).addClass("on");$("label input").prop("checked", true);$("label").addClass("on");for (var i = 0; i < check.length; i++) {sell = check[i].attributes["sellprice"].nodeValue;qty = check[i].attributes["qty"].nodeValue;jiage = sell * qty;quanjia += jiage;}document.getElementsByClassName('shop_zjg')[0].innerHTML = quanjia;zongjia = 0;}});