小程序开发 - 购买数量之加减限制

需求：

• 至少选择一件
• 最多选择3件

这个比较简单，就不多说了，直接上代码

wxml

<!-- 商品数量 -->
<view class=‘shop-number‘>
    <view class=‘shop-number-left‘>
        <view class=‘shop-number-left-name‘>购买数量</view>
        <view class=‘shop-number-left-desc‘>每人限购3件</view>
    </view>
    <view class=‘shop-number-right‘>
        <view class="shop-number-right-reduce {{payPopUp.minusBtn?‘disable-btn‘:‘‘}}" bindtap=‘minusCount‘>-</view>
        <view class=‘shop-number-right-input‘>{{payPopUp.submited.pay_number}}</view>
        <view class="shop-number-right-plus {{payPopUp.addBtn?‘disable-btn‘:‘‘}}" bindtap=‘addCount‘>+</view>
    </view>
</view>

js

data: {
    payPopUp: {
        submited: {
            pay_number: 1,
        },
        addBtn: false,
        minusBtn : true,
    }
},
// 增加
addCount: function() {
    let pay_number = this.data.payPopUp.submited.pay_number;
    if (pay_number != 3) {
        this.setData({
            [‘payPopUp.submited.pay_number‘]: ++pay_number,
            [‘payPopUp.minusBtn‘]: false
        })
        if (pay_number == 3) {
            this.setData({
                [‘payPopUp.addBtn‘]: true
            })
        }
    }
},

// 减少
minusCount: function() {
    let pay_number = this.data.payPopUp.submited.pay_number;
    if (pay_number != 1) {
        this.setData({
            [‘payPopUp.submited.pay_number‘]: --pay_number,
            [‘payPopUp.addBtn‘]: false
        })
        if (pay_number == 1) {
            this.setData({
                [‘payPopUp.minusBtn‘]: true
            })
        }
    }
}

wxss

/* 购买数量 */
.shop-number {
    width: 670rpx;
    height: 120rpx;
    padding: 20rpx 0;
    box-sizing: border-box;
    display: flex;
    justify-content: space-between;
    border-bottom: 1rpx solid #f2f2f2;

}
.shop-number-left {
    width: 220rpx;
    height: 80rpx;
}
.shop-number-left-name {
    line-height: 40rpx;
    font-size: 34rpx;

}
.shop-number-left-desc {
    line-height: 40rpx;
    font-size: 22rpx;
    color: rgb(250, 99, 39);

}
.shop-number-right {
    width: 300rpx;
    display: flex;
    height: 80rpx;
    padding: 5rpx 0;
    box-sizing: border-box;
}
.shop-number-right view{
    line-height: 70rpx;
    height: 70rpx;
    width: 100rpx;
    text-align: center;
    box-sizing: border-box;
    border: 1rpx solid #f2f2f2;
}
.shop-number-right-reduce {
    /* background: yellow; */
    border-radius: 10rpx 0 0 10rpx;
    border-right: 0;
}
.shop-number-right-input {
    /* background: red; */
    border-left: 0;
    border-right: 0;
}
.shop-number-right-plus {
    /* background: goldenrod; */
    border-radius: 0 10rpx 10rpx 0;
    border-left: 0;
}
.shop-number-right-reduce,.shop-number-right-plus{
    line-height: 60rpx !important;
}
.disable-btn {
    background: #f1f1f1;
}

原文地址：https://www.cnblogs.com/cap-rq/p/10087048.html