续上一篇的文章：微信小程序之购物数量加减 —— 微信小程序实战商城系列（3）
所提及的购物数量的加减，现在说说商品属性值联动选择。

为了让同学们有个直观的了解，到电商网截了一个图片，就是红圈所示的部分

现在就为大家介绍这个小组件，在小程序中，该如何去写
下图为本项目的图：

wxml：

<view class="title">商品属性值联动选择</view> <!--options--> <view class="commodity_attr_list"> <!--每组属性--> <view class="attr_box" wx:for="{{attrValueList}}" wx:for-item="attrValueObj" wx:for-index="attrIndex"> <!--属性名--> <view class="attr_name">{{attrValueObj.attrKey}}</view> <!--属性值--> <view class="attr_value_box"> <!--每个属性值--> <view class="attr_value {{attrIndex==firstIndex || attrValueObj.attrValueStatus[valueIndex]?(value==attrValueObj.selectedValue?'attr_value_active':''):'attr_value_disabled'}}" bindtap="selectAttrValue" data-status="{{attrValueObj.attrValueStatus[valueIndex]}}" data-value="{{value}}" data-key="{{attrValueObj.attrKey}}" data-index="{{attrIndex}}" data-selectedvalue="{{attrValueObj.selectedValue}}" wx:for="{{attrValueObj.attrValues}}" wx:for-item="value" wx:for-index="valueIndex">{{value}}</view> </view> </view> </view> <!--button--> <view class="weui-btn-area"> <button class="weui-btn" type="primary" bindtap="submit">确定</button> </view>

wxss：

.title { padding: 10rpx 20rpx; margin: 10rpx 0; border-left: 4rpx solid #ccc; } .commodity_attr_list { background: #fff; padding: 0 20rpx; font-size: 26rpx; overflow: hidden; width: 100%; } .attr_box { width: 100%; overflow: hidden; border-bottom: 1rpx solid #ececec; } .attr_name { width: 20%; float: left; padding: 15rpx 0; } .attr_value_box { width: 80%; float: left; padding: 15rpx 0; overflow: hidden; } .attr_value { float: left; padding: 0 10rpx; margin: 0 10rpx; border: 1rpx solid #ececec; } .attr_value_active { background: #FFCC00; border-radius: 10rpx; color: #fff; padding: 0 10rpx; } .attr_value_disabled { color: #ccc; } .btn-area { margin: 1.17647059em 15px 0.3em; } .btn { margin-top: 15px; background-color:#FFCC00; color: #fff; } .btn:first-child { margin-top: 0; }

js：

数据部分，一般情况都是访问接口获取数据的，这里并没有使用网络访问，为了简化demo，直接把一组数据放在data对象中。

Page({ data: { firstIndex: -1, //准备数据 //数据结构：以一组一组来进行设定 commodityAttr: [ { priceId: 1, price: 35.0, "stock": 8, "attrValueList": [ { "attrKey": "型号", "attrValue": "2" }, { "attrKey": "颜色", "attrValue": "白色" }, { "attrKey": "大小", "attrValue": "小" }, { "attrKey": "尺寸", "attrValue": "S" } ] }, { priceId: 2, price: 35.1, "stock": 9, "attrValueList": [ { "attrKey": "型号", "attrValue": "1" }, { "attrKey": "颜色", "attrValue": "黑色" }, { "attrKey": "大小", "attrValue": "小" }, { "attrKey": "尺寸", "attrValue": "M" } ] }, { priceId: 3, price: 35.2, "stock": 10, "attrValueList": [ { "attrKey": "型号", "attrValue": "1" }, { "attrKey": "颜色", "attrValue": "绿色" }, { "attrKey": "大小", "attrValue": "大" }, { "attrKey": "尺寸", "attrValue": "L" } ] }, { priceId: 4, price: 35.2, "stock": 10, "attrValueList": [ { "attrKey": "型号", "attrValue": "1" }, { "attrKey": "颜色", "attrValue": "绿色" }, { "attrKey": "大小", "attrValue": "大" }, { "attrKey": "尺寸", "attrValue": "L" } ] } ], attrValueList: [] }, onShow: function () { this.setData({ includeGroup: this.data.commodityAttr }); this.distachAttrValue(this.data.commodityAttr); // 只有一个属性组合的时候默认选中 // console.log(this.data.attrValueList); if (this.data.commodityAttr.length == 1) { for (var i = 0; i < this.data.commodityAttr[0].attrValueList.length; i++) { this.data.attrValueList[i].selectedValue = this.data.commodityAttr[0].attrValueList[i].attrValue; } this.setData({ attrValueList: this.data.attrValueList }); } }, distachAttrValue: function (commodityAttr) { /** 将后台返回的数据组合成类似 { attrKey:'型号', attrValueList:['1','2','3'] } */ // 把数据对象的数据（视图使用），写到局部内 var attrValueList = this.data.attrValueList; // 遍历获取的数据 for (var i = 0; i < commodityAttr.length; i++) { for (var j = 0; j < commodityAttr[i].attrValueList.length; j++) { var attrIndex = this.getAttrIndex(commodityAttr[i].attrValueList[j].attrKey, attrValueList); // console.log('属性索引', attrIndex); // 如果还没有属性索引为-1，此时新增属性并设置属性值数组的第一个值；索引大于等于0，表示已存在的属性名的位置 if (attrIndex >= 0) { // 如果属性值数组中没有该值，push新值；否则不处理 if (!this.isValueExist(commodityAttr[i].attrValueList[j].attrValue, attrValueList[attrIndex].attrValues)) { attrValueList[attrIndex].attrValues.push(commodityAttr[i].attrValueList[j].attrValue); } } else { attrValueList.push({ attrKey: commodityAttr[i].attrValueList[j].attrKey, attrValues: [commodityAttr[i].attrValueList[j].attrValue] }); } } } // console.log('result', attrValueList) for (var i = 0; i < attrValueList.length; i++) { for (var j = 0; j < attrValueList[i].attrValues.length; j++) { if (attrValueList[i].attrValueStatus) { attrValueList[i].attrValueStatus[j] = true; } else { attrValueList[i].attrValueStatus = []; attrValueList[i].attrValueStatus[j] = true; } } } this.setData({ attrValueList: attrValueList }); }, getAttrIndex: function (attrName, attrValueList) { // 判断数组中的attrKey是否有该属性值 for (var i = 0; i < attrValueList.length; i++) { if (attrName == attrValueList[i].attrKey) { break; } } return i < attrValueList.length ? i : -1; }, isValueExist: function (value, valueArr) { // 判断是否已有属性值 for (var i = 0; i < valueArr.length; i++) { if (valueArr[i] == value) { break; } } return i < valueArr.length; }, selectAttrValue: function (e) { var attrValueList = this.data.attrValueList; var index = e.currentTarget.dataset.index;//属性索引 var key = e.currentTarget.dataset.key; var value = e.currentTarget.dataset.value; if (e.currentTarget.dataset.status || index == this.data.firstIndex) { if (e.currentTarget.dataset.selectedvalue == e.currentTarget.dataset.value) { // 取消选中 this.disSelectValue(attrValueList, index, key, value); } else { // 选中 this.selectValue(attrValueList, index, key, value); } } }, selectValue: function (attrValueList, index, key, value, unselectStatus) { // console.log('firstIndex', this.data.firstIndex); var includeGroup = []; if (index == this.data.firstIndex && !unselectStatus) { // 如果是第一个选中的属性值，则该属性所有值可选 var commodityAttr = this.data.commodityAttr; // 其他选中的属性值全都置空 // console.log('其他选中的属性值全都置空', index, this.data.firstIndex, !unselectStatus); for (var i = 0; i < attrValueList.length; i++) { for (var j = 0; j < attrValueList[i].attrValues.length; j++) { attrValueList[i].selectedValue = ''; } } } else { var commodityAttr = this.data.includeGroup; } // console.log('选中', commodityAttr, index, key, value); for (var i = 0; i < commodityAttr.length; i++) { for (var j = 0; j < commodityAttr[i].attrValueList.length; j++) { if (commodityAttr[i].attrValueList[j].attrKey == key && commodityAttr[i].attrValueList[j].attrValue == value) { includeGroup.push(commodityAttr[i]); } } } attrValueList[index].selectedValue = value; // 判断属性是否可选 for (var i = 0; i < attrValueList.length; i++) { for (var j = 0; j < attrValueList[i].attrValues.length; j++) { attrValueList[i].attrValueStatus[j] = false; } } for (var k = 0; k < attrValueList.length; k++) { for (var i = 0; i < includeGroup.length; i++) { for (var j = 0; j < includeGroup[i].attrValueList.length; j++) { if (attrValueList[k].attrKey == includeGroup[i].attrValueList[j].attrKey) { for (var m = 0; m < attrValueList[k].attrValues.length; m++) { if (attrValueList[k].attrValues[m] == includeGroup[i].attrValueList[j].attrValue) { attrValueList[k].attrValueStatus[m] = true; } } } } } } // console.log('结果', attrValueList); this.setData({ attrValueList: attrValueList, includeGroup: includeGroup }); var count = 0; for (var i = 0; i < attrValueList.length; i++) { for (var j = 0; j < attrValueList[i].attrValues.length; j++) { if (attrValueList[i].selectedValue) { count++; break; } } } if (count < 2) {// 第一次选中，同属性的值都可选 this.setData({ firstIndex: index }); } else { this.setData({ firstIndex: -1 }); } }, disSelectValue: function (attrValueList, index, key, value) { var commodityAttr = this.data.commodityAttr; attrValueList[index].selectedValue = ''; // 判断属性是否可选 for (var i = 0; i < attrValueList.length; i++) { for (var j = 0; j < attrValueList[i].attrValues.length; j++) { attrValueList[i].attrValueStatus[j] = true; } } this.setData({ includeGroup: commodityAttr, attrValueList: attrValueList }); for (var i = 0; i < attrValueList.length; i++) { if (attrValueList[i].selectedValue) { this.selectValue(attrValueList, i, attrValueList[i].attrKey, attrValueList[i].selectedValue, true); } } }, submit: function () { var value = []; for (var i = 0; i < this.data.attrValueList.length; i++) { if (!this.data.attrValueList[i].selectedValue) { break; } value.push(this.data.attrValueList[i].selectedValue); } if (i < this.data.attrValueList.length) { wx.showToast({ title: '请完善属性', icon: 'loading', duration: 1000 }) } else { wx.showToast({ title: '选择的属性：' + value.join('-'), icon: 'sucess', duration: 1000 }) } } })

运行效果：

demo地址：微信小程序商城项目之商品属性值联动选择

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。