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超轻量级php框架startmvc

react实现移动端下拉菜单的示例代码

更新时间:2020-09-30 11:42:01 作者:startmvc
前言项目中要实现类似与vant的DropdownMenu:下拉菜单。看了vans的效果其实也没什么难度,于是

前言

项目中要实现类似与vant的DropdownMenu:下拉菜单。看了vans 的效果 其实也没什么难度,于是动手鲁了一个这样的组件。 项目的技术栈为react全家桶+material UI + ant Design mobile。

vans的效果

我自己实现的效果

思路

常规做法获取dom元素,动态修改选中dom的innerHtml。 当然这种方式不是react推荐的

我的做法既然react不推荐直接操作dom元素,那可以采用动态动态修改class的方式达到效果,例如:


let cls ="normal"
div未被选中时
<div className={cls}/> 
div被选中时
cls+=" current"
<div className ={cls}>

实现步骤

顶部tab采用三个div的方式布局,由于需要动态修改tab上的标题,所以定义一个数组,reducer中的tab数据结构如下


let tabs = {};
tabs[TABKAY.AREA] = {
key: TABKAY.AREA,
text: "全部区域",
obj: {}
};
tabs[TABKAY.SORT] = {
key: TABKAY.SORT,
text: "综合排序",
obj: {}
};
tabs[TABKAY.FILTER] = {
key: TABKAY.FILTER,
text: "筛选",
obj: SX
};
const initialState = {
areas: [{ id: "", name: "全部区域" }],
tabs: tabs,
actionKey: TABKAY.AREA,// 标识了当前选中tab
closePanel: true // 标识panel div 是否显示
};



tabUI组件的页面容器渲染方法


renderTabs() {
const { tabs, actionKey, closePanel } = this.props;
//---------
if (!closePanel) {
 fixedBody();
} else {
 looseBody();
}
//---------

let aray = [];
for (let key in tabs) {
 let item = tabs[key];
 let cls = item.key + " item";
 if (item.key === actionKey && !closePanel) {
 cls += " current";
 }

 aray.push(
 <div className={cls} key={item.key} onClick={() => this.onChangeTab(item.key)}>
 {item.text}
 </div>);
}

return aray;
}

样式:这里边有个技巧,就是利用了css元素选择器的伪类的方式巧妙实现了箭头以及箭头的旋转动画


.item {
flex: 1;
font-size: 15px;
border-right: 0.5px solid #eaeaea;
text-align: center;

&:last-child {
 border: none;
}

&.AREA:after, &.SORT:after, &.FILTER:after {
 content: "";
 display: inline-block;
 width: 5px;
 height: 5px;
 margin-bottom: 2px;
 margin-left: 6px;
 border: 2px solid #666;
 border-width: 0 2px 2px 0;
 transform: rotate(45deg);
 -webkit-transform: rotate(45deg);
 -webkit-transition: .3s;
 transition: .3s;
}

&.current {
 color: #0084ff;
}

&.current:after {
 border-color: #0084ff;
 transform: rotate(225deg);
 -webkit-transform: rotate(225deg);
}

chrome 查看元素

全部区域tab被选中:

综合tab被选中

每次点击不同的tab时 都会自动的渲染current这个css样式,这样就实现了下拉菜单的功能。

完整代码


/**
 * Class:
 * Author: miyaliunian
 * Date: 2019/5/26
 * Description: tabs 选择器
 * 医院列表
 */
import React, { Component } from "react";
import { ZHPX, TABKAY } from "@api/Constant";
//Util
import { fixedBody, looseBody } from "@utils/fixRollingPenetration";
//Redux
import { connect } from "react-redux";
import { bindActionCreators } from "redux";
import { actions as tabActions, getTabs, getAreasList, getActionKey, getClosePanel } from "@reduxs/modules/tabs";
import { actions as hospitalActions,} from "@reduxs/modules/hospital";

//样式
import "./tabs.less";

class Tabs extends Component {
 
 /**
 * 变化当前点击的item状态 同时filter 请求
 * @param filterItem 当前选中的元素
 * @param key 哪个tab是选中状态
 */
 changeDoFilter(filterItem, key, event) {
 const { tabActions: { changeFilter }, hospitalActions:{filterHosiContentList} } = this.props;
 event.stopPropagation();
 changeFilter(filterItem, key, (filter) => {
 filterHosiContentList(filter);
 });
 }

 /**
 * 筛选tab确定按钮
 * @param event
 */
 filterPanel(event) {
 const {tabActions:{closePanelAction}, tabs,hospitalActions:{filterHosiContentList}} = this.props;
 event.stopPropagation();
 closePanelAction(()=>{
 filterHosiContentList(tabs)
 })
 }

 /**
 * 点击切换Tab
 * @param key
 */
 onChangeTab(key) {
 const { actionKey,tabActions: { changeTab } } = this.props;
 let closePanel = false;
 //如果前后点击的是同一个tab 就关闭panel
 if (actionKey === key && !this.props.closePanel) {
 closePanel = true;
 }
 closePanel ? looseBody() : fixedBody();
 changeTab(key, closePanel);
 }

 /**
 * 渲染顶部tab
 */
 renderTabs() {
 const { tabs, actionKey, closePanel } = this.props;
 //---------
 if (!closePanel) {
 fixedBody();
 } else {
 looseBody();
 }
 //---------

 let aray = [];
 for (let key in tabs) {
 let item = tabs[key];
 let cls = item.key + " item";
 if (item.key === actionKey && !closePanel) {
 cls += " current";
 }

 aray.push(
 <div className={cls} key={item.key} onClick={() => this.onChangeTab(item.key)}>
 {item.text}
 </div>);
 }

 return aray;
 }

 /**
 * 全部区域
 * @returns {*}
 */
 renderAreaContent() {
 const { areasList } = this.props;
 return areasList.map((item, index) => {
 let cls = item.active + " area-item";
 return (
 <li key={index} className={"area-item"} onClick={(e) => this.changeDoFilter(item, TABKAY.AREA, e)}>
 {item.name}
 </li>
 );
 });
 }


 /**
 * 全部排序
 * @returns {any[]}
 */
 renderSORTContent() {
 let sortList = ZHPX;
 return sortList.map((item, index) => {
 let cls = item.action ? "type-item active" : "type-item";

 return (
 <li key={index} className={cls} onClick={(e) => this.changeDoFilter(item, TABKAY.SORT, e)}>
 {item.name}
 </li>
 );
 });
 }


 /**
 * 筛选
 * @returns {*}
 */

 renderFilterInnerContent(items/*filterList*/) {
 return items.map((item, index) => {
 let cls = "cate-box";
 if (item.active) {
 cls += " active";
 }

 return (
 <div key={index} className={cls} onClick={(e) => this.changeDoFilter(item, TABKAY.FILTER, e)}>
 {item.name}
 </div>
 );
 });

 }

 renderFILTERContent() {
 let filterList = [];
 const { tabs } = this.props;
 filterList = tabs[TABKAY.FILTER].obj;
 return filterList.map((item, index) => {
 return (
 <li key={index} className={"filter-item"}>
 <p className={"filter-title"}>{index == 0 ? `医院类型: ${item.groupTitle}` : `医院等级: ${item.groupTitle}`}</p>
 <div className={"item-content"}>
 {this.renderFilterInnerContent(item.items, filterList)}
 </div>
 </li>
 );
 });
 }

 /**
 * 渲染过滤面板
 */
 renderContent() {
 const { tabs, actionKey } = this.props;
 let array = [];
 for (let key in tabs) {
 let item = tabs[key];
 let cls = item.key + "-panel";
 if (item.key === actionKey) {
 cls += " current";
 }

 // 全部区域
 if (item.key === TABKAY.AREA) {
 array.push(
 <ul key={item.key} className={cls}>
 {this.renderAreaContent()}
 </ul>
 );
 } else if (item.key === TABKAY.SORT) {
 // 综合排序
 array.push(
 <ul key={item.key} className={cls}>
 {this.renderSORTContent()}
 </ul>
 );
 } else if (item.key === TABKAY.FILTER) {
 // 筛选
 array.push(
 <ul key={item.key} className={cls}>
 {this.renderFILTERContent()}
 <div className={"filterBtn"} onClick={(e) => this.filterPanel(e)}>
 确定
 </div>
 </ul>
 );
 }

 }
 return array;
 }


 render() {
 const { closePanel, tabActions: { closePanelAction } } = this.props;
 let cls = "panel";
 if (!closePanel) {
 cls += " show";
 } else {
 cls = "panel";
 }
 return (
 <div className={"tab-header"}>
 <div className={"tab-header-top border-bottom"}>
 {this.renderTabs()}
 </div>
 <div className={cls} onClick={() => closePanelAction(()=>{})}>
 <div className={"panel-inner"}>
 {this.renderContent()}
 </div>
 </div>
 </div>
 );
 }


 componentDidMount() {
 const { areasList, tabActions: { loadAreas } } = this.props;
 if (areasList && areasList.length !== 1) {
 return;
 }
 loadAreas();
 }
}

const mapStateToProps = state => {
 return {
 areasList: getAreasList(state),
 tabs: getTabs(state),
 actionKey: getActionKey(state),
 closePanel: getClosePanel(state)
 };
};

const mapDispatchToProps = dispatch => {
 return {
 tabActions: bindActionCreators(tabActions, dispatch),
 hospitalActions: bindActionCreators(hospitalActions, dispatch)
 };
};

export default connect(mapStateToProps, mapDispatchToProps)(Tabs);

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脚本之家。

react 移动端下拉菜单 react 下拉菜单