城市选择器应该是比较常用的一个组件，用户可以去选择自己的城市，选择城市后返回，又根据自己选择的城市搜索小区。
功能展示
这是选择结果
这是选择城市
这是搜索小区
这是搜索小区接口，key为城市名字，id是城市的id
假如切换城市
搜索接口也会相应变化，id=0997 就是指定的搜索城市id
技术栈
vue2.0+vue-router+webpack+vuex+less+better-scroll+axios
webpack
resolve: {extensions: ['.js', '.vue', '.json'],alias: {'vue$': 'vue/dist/vue.esm.js','src': resolve('src'),'common' : resolve('src/common'),'components': resolve('src/components'),'base': resolve('src/base'),"api":resolve('src/api')}},
用less需要引入less和less-loader，但是不需要在webpack操作，webpack已经操作好了
技术栈介绍
所有城市是本地维护的，在city.js中
1、axios封装
import {ajaxUrl} from "./config"import axios from 'axios'export function getSearchData(key,id){var obj = {op:"search",key,id}return axios.get(ajaxUrl.searcUrl,{params: obj}).then((res)=>{return Promise.resolve(res.data);}).catch((err)=>{return Promise.resolve(err);})}
2、axios调用，因为目前没有接口，所以只是模拟演示接口，但不影响逻辑
import {getSearchData} from "api/search"_getDiscList(key,id){this.searchList=["八方城","西溪北苑北区","西溪北苑西区","西溪北苑东区","万科城","恒大城","西溪科技园","未来科技城","智慧城","春天家园","茶张新苑","双水磨小区","小区1","小区2","小区3","小区4","小区5","小区6","小区7"];getSearchData(key,id).then((res)=>{},(err)=>{})},
3、vuex状态管理，vuex我就不介绍了，具体可以去看官网
4、主要介绍一下state中变量的含义
import {initial} from "common/js/config"const state = {selectCity:initial.city,selectCommunity:munity,hasSelCityID:-1}export default state
5、config.js
export const initial = {city:"杭州",community:"八方城"}
selectCity是选择的城市
selectCommunity是选择的小区
hasSelCityID是选择城市的id，根据此id选择对应小区
6、better-scroll
better-scroll 是之前封装好的一个页面滚动组件
7、vue-router
8、页面滑动对应title也变化原理
首先需要记住变量scrollY，这是记录页面滚动到哪个title
data(){return{city:[],scrollY: -1,currentIndex:0,diff:-1,}},
初始化的时候初始化这三个变量，probetype=3是better-scroll可支持touchmove事件的参数
created(){this.touch = {};this.listenScroll = true;this.listenHeight = [];this.probetype = 3;},
时刻计算高度，并检测页面滚动到哪个位置
watch:{city(){setTimeout(()=>{this._calculateHeight()},20)},scrollY(newY){// 滚动到中间部分const listenHeight = this.listenHeight;// 滚动到头部以上if (newY>=-25) {this.currentIndex = 0;return;}for(let i=0;i<listenHeight.length-1;i++){let height1 = listenHeight[i];let height2 = listenHeight[i+1];// 如果没在下限，且在height1和height2之间if (-newY>=height1 && -newY<=height2) {this.currentIndex = i;this.diff = height2 + newY;return;}}},diff(newVal){let fixedTop = (newVal>0 && newVal<TITLE_HEIGHT)?newVal-TITLE_HEIGHT:0;if (this.fixedTop === fixedTop) {return}this.fixedTop = fixedTop;this.$refs.fixed.style.transform = `translate3d(0,${fixedTop}px,0)`}}
_calculateHeight(){this.listenHeight = [];const list = this.$refs.listGroup;let height = 0;this.listenHeight.push(height);for(let i =0;i<list.length;i++){let item = list[i];height +=item.clientHeight;this.listenHeight.push(height);}},
滚动指定位置
_scrollTo(index){if (!index && index!=0) {return}// 点击右边字母跳到指定位置并高亮this.scrollY = -this.listenHeight[index]-1;this.$refs.cityList.scrollToElement(this.$refs.listGroup[index],0);},
改变标题
fixedTitle(){if (this.scrollY>0) {return ""}return this.city[this.currentIndex]?this.city[this.currentIndex].initial:""}
点击字右边索引跳转指定位置
onShortcutTouchStart(e){let anchorIndex = getData(e.target,'index');console.log(anchorIndex);let firstTouch = e.touches[0];this.touch.y1 = firstTouch.pageY;this.touch.anchorIndex = anchorIndex;// this.$refs.singerlist.scrollToElement(this.$refs.listGroup[anchorIndex],0);this._scrollTo(anchorIndex)},
9、搜索组件
搜索输入框是一个组件，组件负责监听input的model变化，只要变化就派发事件，引用该组件的组件，只需要监听派发的事件即可
created(){this.$watch('query',(newQuery)=>{this.$emit('query',newQuery)})}
11、城市搜索，支持首字母（不区分大小写）搜索
首先给城市加首字母
_addFirstLetter(citylist){for(var i=0;i<citylist.length;i++){for(var j=0;j<citylist[i].list.length;j++){citylist[i].list[j]['firstLetter'] = citylist[i].initial;}}this._formatCityList(citylist);},
序列化数组
// 序列化数组 _formatCityList(arr){var letterArr = {};for (var i = 0; i < arr.length; i++) {if (!(arr[i]['initial'] in letterArr)) {letterArr[arr[i]['initial']] = [];for(var j=0;j<arr[i].list.length;j++){letterArr[arr[i]['initial']].push(arr[i].list[j]);}}else{for(var j=0;j<arr[i].list.length;j++){letterArr[arr[i]['initial']].push(arr[i].list[j]);}}}this.letterList = letterArr;},
搜索
正则var reg = new RegExp(newVal == '' ? 'xxyy' :newVal, 'ig'); ig是不区分大小写
// 搜索 _search(newVal){var reg = new RegExp(newVal == '' ? 'xxyy' :newVal, 'ig');var _arr = [];for(var i in this.letterList){for(var j = 0; j < this.letterList[i].length; j++){if(reg.test(this.letterList[i][j]['name']) ||reg.test(this.letterList[i][j]['firstLetter'])){_arr.push(this.letterList[i][j]);}}}this.searchList = _arr;},
因为引入的搜索框组件，所以只需要监听input内容改变后派发的事件即可
this._search(newVal);this.queryCity = newVal;
data 搜索结果会放在searchList里面，只需要v-for即可，但是需要边缘处理，没有搜索结果，有一个UI上的一个展示
data(){return{city:[],letterList:[],searchList: [], //搜索结果queryCity:"",placeholder:"输入城市名称"}},
10、每次点击搜索城市后触发mutation，修改state
selectItem(item){this.afterSelect(item)},selectSearchItem(item){this.afterSelect(item)},// 选择之后的操作 afterSelect(item){this.$router.back();this.setCity(item.name);this.setCityId(item.zip);},...mapMutations({setCity:"SET_CITY",setCityId:"SET_CITYID"})
推荐使用vuex钩子，具体如何使用可去看官网
import {mapMutations} from "vuex"import {mapGetters} from "vuex"
业务功能模板
1、select.vue
<template lang="html"><!-- <transition name="slide"> --><div><div @click="city" class="city clearfix"><i>所在城市</i><em></em><span>{{selCity}}</span></div><div @click="community" class="community clearfix"><i>小区名称</i><em></em><span>{{selCommunity}}</span></div></div><!-- </transition> --></template>
2、city.vue
<transition name="slide"><div class="xin-widget-citys animated"><SearchBox class="search" @query="query" :placeholder="placeholder"></SearchBox><div class="currentCity" v-if="queryCity===''"><ul><h2>当前定位城市</h2><li>杭州</li></ul></div><Scroll :data="searchList" class="searchlist" v-if="queryCity !== ''" :class="{'bg':searchList.length === 0}"><div><ul v-if="searchList.length!==0"><li class="bdb" v-for="item in searchList" @click="selectSearchItem(item)">{{item.name}}</li></ul><img v-else src="../../common/img/404.png" class="nomatch"/></div></Scroll><CityList class="city" v-if="queryCity===''" @selectItem="selectItem"></CityList></div></transition>
3、search.vue
<transition name="slide"><div class="xin-widget-citys animated"><SearchBox class="search" @query="query" :placeholder="placeholder"></SearchBox><Scroll :data="searchList" class="searchlist" v-if="queryCity !== ''" :class="{'bg':searchList.length === 0}"><div><ul v-if="searchList.length!==0"><li v-for="item in searchList" @click="selectSearchItem(item)">{{item}}</li></ul><img v-else src="../../common/img/404.png" class="nomatch"/></div></Scroll></div></transition>
基础组件模板
1、city-list.vue
<Scroll class="citylist" :data="city" ref="cityList" :listenScroll="listenScroll" @scroll="scroll" :probetype="probetype"><div><div v-for="(item,index) in city" class="allCity" ref="listGroup"><h2>{{item.initial}}</h2><ul><li v-for="city in item.list" @click="selectItem(city)">{{city.name}}</li></ul></div></div><div class="list-shortcut" @touchstart="onShortcutTouchStart"><ul><li class="starCity"></li><li v-for="(item,index) in city" class="item" :data-index="index">{{item.initial}}</li></ul></div><div class="list-fixed" v-show="fixedTitle" ref="fixed"><h1 class="fixed-title">{{fixedTitle}}</h1></div></Scroll>
2、search-box.vue
<template><div class="search-box"><i class="icon-search"></i><input ref="query" class="box" :placeholder="placeholder" v-model="query"/></div></template>
总结
以上就是城市选择器的大概介绍，源码我已经放在了我的github上了，有需要可去下载，如果有帮助，麻烦给个star，鼓励我继续努力，谢谢！
代码地址：/dirkhe1051931999/writeBlog
