*{font-style: normal}

    .gw{margin: 8px;}

    .gw::after{display: block;clear: both;content: '';margin: 10px;}

    .gw_num{border: 1px solid #dbdbdb;width: 110px;line-height: 26px;overflow: hidden;float: left;}

    .gw_num em{display: block;height: 26px;width: 26px;float: left;color: #7A7979;border-right: 1px solid #dbdbdb;text-align: center;cursor: pointer;font-style: normal}

    .gw_num .num{display: block;float: left;text-align: center;width: 52px;font-style: normal;font-size: 14px;line-height: 24px;border: 0;}

    .gw_num em.add{float: right;border-right: 0;border-left: 1px solid #dbdbdb;}

    p{margin: 4px;padding: 0}

    .choose,.qx{float: left;width: 20px;height: 20px;border: 1px solid #ccc; border-radius: 100%;margin-right: 10px;}

    .choose-on, .qx-on{background: url(./on.png) no-repeat center center;background-size: 100%;}

    <div class="zong">

        <div class="gw">

            <div class="choose"></div>

            <div class="gw_num">

                <em class="jian">-</em>

                <input type="text" value="0" class="num"/>

                <em class="add">+</em>

            </div>

            <p>单价<i>20</i>元 总金额：￥<span>0</span></p>

            <div class="del">删除</div>

        </div>

        <div class="gw">

            <div class="choose"></div>

            <div class="gw_num">

                <em class="jian">-</em>

                <input type="text" value="0" class="num"/>

                <em class="add">+</em>

            </div>

            <p>单价<i>40</i>元 总金额：￥<span>0</span></p>

            <div class="del">删除</div>

        </div>

        <div class="gw">

            <div class="choose"></div>

            <div class="gw_num">

                <em class="jian">-</em>

                <input type="text" value="0" class="num"/>

                <em class="add">+</em>

            </div>

            <p>单价<i>40</i>元 总金额：￥<span>0</span></p>

            <div class="del">删除</div>

        </div>

        <div class="gw">

            <div class="choose"></div>

            <div class="gw_num">

                <em class="jian">-</em>

                <input type="text" value="0" class="num"/>

                <em class="add">+</em>

            </div>

            <p>单价<i>40</i>元 总金额：￥<span>0</span></p>

            <div class="del">删除</div>

        </div>

        <div>

            <div class="qx"></div>

            <span>全选</span><span class="gs"></span>

            <p class="a">金额总计：<span>0</span></p>

        </div>

    </div>

    $(function(){

            $('.add').click(function(){

                var n = $(this).prev().val()

                var num = parseInt(n) + 1;

                if(n ==  5){num = 5}  //设置最大数量 5

                $(this).prev().val(num);

                var money = $(this).parents('.gw').find('i').text()

                var sum = money * num

                var p = $(this).parents('.gw').find('span').text(sum)

                // console.log(p)

                // var Sum = $(this).parents('.zong').find('.a > span').text(sum)

                // console.log(Sum)

                jiesuan()

            })

            $('.jian').click(function(){

                var n = $(this).next().val();

                var num = parseInt(n) - 1;

                if(n ==  0){num = 0}  //设置最小数量 0

                console.log(num)

                $(this).next().val(num);

                var money = $(this).parents('.gw').find('i').text()

                var sum = money * num

                var p = $(this).parents('.gw').find('span').text(sum)

                jiesuan()

            })

            //选中

            $('.choose').click(function(){

                $(this).toggleClass('choose-on')

                // console.log('aa')

                jiesuan()

                xz()

                qx()

            })

            //全选

            $('.qx').click(function(){

                $(this).toggleClass('qx-on')

                if($(this).is('.qx-on')){

                    $('.choose').addClass('choose-on')

                }else{

                    $('.choose').removeClass('choose-on')

                }

                jiesuan()

                qx()

            })

            //删除

            $('.del').click(function(){

                if(confirm('确定删除商品')){

                    $(this).parents('.gw').remove()

                }

                jiesuan()

                qx()

                // console.log(a)

            })

        })

        function jiesuan(){

            var num = 0;

            // alert('aa')

            $('.gw').each(function(){

                if($(this).find('.choose').is('.choose-on')){

                    //获取物品单价

                    var dj = $(this).find('i').text()

                    //获取物品数量

                    var sl = $(this).find('.num').val()

                    //合计

                    var hj = dj * sl

                    num += hj;

                }

            })

            $('.a>span').text(num)

        }

        //单选--全选中

        function xz(){

            var choose = $('.choose')

            var choose_on = $('.choose-on')

            if(choose.length == choose_on.length){

                $('.qx').addClass('qx-on')

            }else{

                $('.qx').removeClass('qx-on')

            }

        }

        //全选

        function qx(){

            $('.gs').text(' ')

            var a = $('.choose-on').length;

            $('.gs').text(a)

            if(a > 0){

                $('.gs').prev().text('已选')

            }else{

                $('.gs').prev().text('全选')

            }

        }