Taro小程序自定义顶部导航栏功能的实现

import Taro from '@tarojs/taro';
import React, { Component } from 'react'
import { View } from '@tarojs/components';
import { isFunction } from '../../utils/index' //判断是否为函数，可以用loadsh的_isFunction,也可以自己封装。
import './NavBar.less';


function getSystemInfo () {
 if (Taro.globalSystemInfo && !Taro.globalSystemInfo.ios) {
  return Taro.globalSystemInfo;
 } else {
  // h5环境下忽略navbar
  if (!isFunction(Taro.getSystemInfoSync)) {
   return null;
  }
  let systemInfo = Taro.getSystemInfoSync() || {
   model: '',
   system: ''
  };
  let ios = !!(systemInfo.system.toLowerCase().search('ios') + 1);
  let rect;
  try {
   rect = Taro.getMenuButtonBoundingClientRect ? Taro.getMenuButtonBoundingClientRect() : null;
   if (rect === null) {
    throw 'getMenuButtonBoundingClientRect error';
   }
   //取值为0的情况 有可能width不为0 top为0的情况
   if (!rect.width || !rect.top || !rect.left || !rect.height) {
    throw 'getMenuButtonBoundingClientRect error';
   }
  } catch (error) {
   let gap; //胶囊按钮上下间距 使导航内容居中
   let width = 96; //胶囊的宽度
   if (systemInfo.platform === 'android') {
    gap = 8;
    width = 96;
   } else if (systemInfo.platform === 'devtools') {
    if (ios) {
     gap = 5.5; //开发工具中ios手机
    } else {
     gap = 7.5; //开发工具中android和其他手机
    }
   } else {
    gap = 4;
    width = 88;
   }
   if (!systemInfo.statusBarHeight) {
    //开启wifi的情况下修复statusBarHeight值获取不到
    systemInfo.statusBarHeight = systemInfo.screenHeight - systemInfo.windowHeight - 20;
   }
   rect = {
    //获取不到胶囊信息就自定义重置一个
    bottom: systemInfo.statusBarHeight + gap + 32,
    height: 32,
    left: systemInfo.windowWidth - width - 10,
    right: systemInfo.windowWidth - 10,
    top: systemInfo.statusBarHeight + gap,
    width: width
   };
   console.log('error', error);
   console.log('rect', rect);
  }

  let navBarHeight = '';
  if (!systemInfo.statusBarHeight) {
   //开启wifi和打电话下
   systemInfo.statusBarHeight = systemInfo.screenHeight - systemInfo.windowHeight - 20;
   navBarHeight = (function () {
    let gap = rect.top - systemInfo.statusBarHeight;
    return 2 * gap + rect.height;
   })();

   systemInfo.statusBarHeight = 0;
   systemInfo.navBarExtendHeight = 0; //下方扩展4像素高度 防止下方边距太小
  } else {
   navBarHeight = (function () {
    let gap = rect.top - systemInfo.statusBarHeight;
    return systemInfo.statusBarHeight + 2 * gap + rect.height;
   })();
   if (ios) {
    systemInfo.navBarExtendHeight = 4; //下方扩展4像素高度 防止下方边距太小
   } else {
    systemInfo.navBarExtendHeight = 0;
   }
  }

  systemInfo.navBarHeight = navBarHeight; //导航栏高度不包括statusBarHeight
  systemInfo.capsulePosition = rect; //右上角胶囊按钮信息bottom: 58 height: 32 left: 317 right: 404 top: 26 width: 87 目前发现在大多机型都是固定值 为防止不一样所以会使用动态值来计算nav元素大小
  systemInfo.ios = ios; //是否ios
  Taro.globalSystemInfo = systemInfo; //将信息保存到全局变量中,后边再用就不用重新异步获取了
  //console.log('systemInfo', systemInfo);
  return systemInfo;
 }
}
let globalSystemInfo = getSystemInfo();
class NavBar extends Component {
 constructor(props) {
  super(props);
  this.state = {
   configStyle: this.setStyle(globalSystemInfo)
  };
 }
 static options = {
  multipleSlots: true,
  addGlobalClass: true
 };

 UNSAFE_componentWillMount () {
  //获取高度
  // let query = Taro.createSelectorQuery().in(this.$scope)
  // query.select('.lxy-nav-bar').boundingClientRect(rect=>{
  //  const navHeight = rect.height
  //  this.props.personalHomeMod.changeState('navHeight',navHeight)
  // 	// console.log('navHeight',toJS(this.props.personalHomeMod.state))
  // }).exec()
 }
 componentDidShow () {
  if (globalSystemInfo.ios) {
   globalSystemInfo = getSystemInfo();
   this.setState({
    configStyle: this.setStyle(globalSystemInfo)
   });
  }
 }
 handleBackClick () {
  if (isFunction(this.props.onBack)) {
   this.props.onBack();
  } else {
   const pages = Taro.getCurrentPages();
   if (pages.length >= 2) {
    Taro.navigateBack({
     delta: this.props.delta
    });
   }
  }
 }
 handleGoHomeClick () {
  if (isFunction(this.props.onHome)) {
   this.props.onHome();
  }
 }
 handleSearchClick () {
  if (isFunction(this.props.onSearch)) {
   this.props.onSearch();
  }
 }
 static defaultProps = {
  extClass: '',
  background: 'rgba(255,255,255,1)', //导航栏背景
  color: '#000000',
  title: '',
  searchText: '点我搜索',
  searchBar: false,
  back: false,
  home: false,
  iconTheme: 'black',
  delta: 1
 };

 setStyle (systemInfo) {
  const { statusBarHeight, navBarHeight, capsulePosition, navBarExtendHeight, ios, windowWidth } = systemInfo;
  const { back, home, title, color } = this.props;
  let rightDistance = windowWidth - capsulePosition.right; //胶囊按钮右侧到屏幕右侧的边距
  let leftWidth = windowWidth - capsulePosition.left; //胶囊按钮左侧到屏幕右侧的边距

  let navigationbarinnerStyle = [
   `color:${color}`,
   //`background:${background}`,
   `height:${navBarHeight + navBarExtendHeight}px`,
   `padding-top:${statusBarHeight}px`,
   `padding-right:${leftWidth}px`,
   `padding-bottom:${navBarExtendHeight}px`
  ].join(';');
  let navBarLeft;
  if ((back && !home) || (!back && home)) {
   navBarLeft = [
    `width:${capsulePosition.width}px`,
    `height:${capsulePosition.height}px`,
    `margin-left:0px`,
    `margin-right:${rightDistance}px`
   ].join(';');
  } else if ((back && home) || title) {
   navBarLeft = [
    `width:${capsulePosition.width}px`,
    `height:${capsulePosition.height}px`,
    `margin-left:${rightDistance}px`
   ].join(';');
  } else {
   navBarLeft = [`width:auto`, `margin-left:0px`].join(';');
  }
  return {
   navigationbarinnerStyle,
   navBarLeft,
   navBarHeight,
   capsulePosition,
   navBarExtendHeight,
   ios,
   rightDistance
  };
 }

 render () {
  const {
   navigationbarinnerStyle,
   navBarLeft,
   navBarHeight,
   capsulePosition,
   navBarExtendHeight,
   ios,
   rightDistance
  } = this.state.configStyle;
  const {
   title,
   background,
   backgroundColorTop,
   back,
   home,
   searchBar,
   searchText,
   iconTheme,
   extClass
  } = this.props;
  let nav_bar__center;
  if (title) {
   nav_bar__center = <text>{title}</text>;
  } else if (searchBar) {
   nav_bar__center = (
    <View
     className='lxy-nav-bar-search'
     style={`height:${capsulePosition.height}px;`}
     onClick={this.handleSearchClick.bind(this)}
    >
     <View className='lxy-nav-bar-search__icon' />
     <View className='lxy-nav-bar-search__input'>{searchText}</View>
    </View>
   );
  } else {
   /* eslint-disable */
   nav_bar__center = this.props.renderCenter;
   /* eslint-enable */
  }
  return (
   <View
    className={`lxy-nav-bar ${ios ? 'ios' : 'android'} ${extClass}`}
    style={`background: ${backgroundColorTop ? backgroundColorTop : background};height:${navBarHeight +
     navBarExtendHeight}px;`}
   >
    <View
     className={`lxy-nav-bar__placeholder ${ios ? 'ios' : 'android'}`}
     style={`padding-top: ${navBarHeight + navBarExtendHeight}px;`}
    />
    <View
     className={`lxy-nav-bar__inner ${ios ? 'ios' : 'android'}`}
     style={`background:${background};${navigationbarinnerStyle};`}
    >
     <View className='lxy-nav-bar__left' style={navBarLeft}>
      {back && !home && (
       <View
        onClick={this.handleBackClick.bind(this)}
        className={`lxy-nav-bar__button lxy-nav-bar__btn_goback ${iconTheme}`}
       />
      )}
      {!back && home && (
       <View
        onClick={this.handleGoHomeClick.bind(this)}
        className={`lxy-nav-bar__button lxy-nav-bar__btn_gohome ${iconTheme}`}
       />
      )}
      {back && home && (
       <View className={`lxy-nav-bar__buttons ${ios ? 'ios' : 'android'}`}>
        <View
         onClick={this.handleBackClick.bind(this)}
         className={`lxy-nav-bar__button lxy-nav-bar__btn_goback ${iconTheme}`}
        />
        <View
         onClick={this.handleGoHomeClick.bind(this)}
         className={`lxy-nav-bar__button lxy-nav-bar__btn_gohome ${iconTheme}}`}
        />
       </View>
      )}
      {!back && !home && this.props.renderLeft}
     </View>
     <View className='lxy-nav-bar__center' style={`padding-left: ${rightDistance}px`}>
      {nav_bar__center}
     </View>
     <View className='lxy-nav-bar__right' style={`margin-right: ${rightDistance}px`}>
      {this.props.renderRight}
     </View>
    </View>
   </View>
  );
 }
}

export default NavBar;

view,
text,
scroll-view,
input,
button,
image,
cover-view {
 box-sizing: border-box;
}
page {
 /* prettier-ignore */
 --height: 44PX; /* 4*2+32 */
 /* prettier-ignore */
 --right: 97PX; /* 10+87 */
 /* prettier-ignore */
 --navBarExtendHeight: 4PX;
 /* prettier-ignore */
 --navBarHeight: 68PX;
 box-sizing: border-box;
}
.lxy-nav-bar .ios {
 /* prettier-ignore */
 --height: 44PX; /* 4*2+32 */
 /* prettier-ignore */
 --right: 97PX; /* 10+87 */
 /* prettier-ignore */
 --navBarExtendHeight: 4PX;
 box-sizing: border-box;
}
.lxy-nav-bar .android {
 /* prettier-ignore */
 --height: 48PX; /* 8*2+32 */
 /* prettier-ignore */
 --right: 96PX; /* 10+87 */
 /* prettier-ignore */
 --navBarExtendHeight: 4PX;
 box-sizing: border-box;
}
.lxy-nav-bar .devtools {
 /* prettier-ignore */
 --height: 42PX; /* 5*2+32 */
 /* prettier-ignore */
 --right: 88PX; /* 10+87 */
 /* prettier-ignore */
 --navBarExtendHeight: 4PX;
 box-sizing: border-box;
}
.lxy-nav-bar__inner {
 position: fixed;
 top: 0;
 left: 0;
 z-index: 5001;
 /* prettier-ignore */
 height: var(--navBarHeight);
 display: flex;
 align-items: center;
 padding-right: var(--right);
 width: 100%;
 /* prettier-ignore */
 padding-top: 20PX;
 /* prettier-ignore */
 padding-bottom:4PX;
 .placeholder {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
 }
}
.lxy-nav-bar__inner .lxy-nav-bar__left {
 position: relative;
 width: var(--right);
 /* prettier-ignore */
 height: 32PX;
 /* padding-left: 10PX; */
 /* prettier-ignore */
 margin-left:10PX;
 display: flex;
 align-items: center;
}
.lxy-nav-bar__buttons {
 height: 100%;
 width: 100%;
 display: flex;
 align-items: center;
 /* prettier-ignore */
 border-radius: 16PX;
 border: 1px solid rgba(204, 204, 204, 0.6);
 position: relative;
}
.lxy-nav-bar__buttons.android {
 border: 1px solid rgba(234, 234, 234, 0.6);
}
.lxy-nav-bar__buttons::after {
 position: absolute;
 content: '';
 width: 1px;
 /* prettier-ignore */
 height: 18.4PX;
 background: rgba(204, 204, 204, 0.6);
 left: 50%;
 top: 50%;
 transform: translate(-50%, -50%);
}
.lxy-nav-bar__buttons.android::after {
 background: rgba(234, 234, 234, 0.6);
}
.lxy-nav-bar__button {
 width: 50%;
 height: 100%;
 display: flex;
 /* prettier-ignore */
 font-size: 12PX;
 background-repeat: no-repeat;
 background-position: center center;
 background-size: 1em 2em;
}

.lxy-nav-bar__inner .lxy-nav-bar__left .lxy-nav-bar__btn_goback:active,
.lxy-nav-bar__inner .lxy-nav-bar__left .lxy-nav-bar__btn_gohome:active {
 opacity: 0.5;
}
.lxy-nav-bar__inner .lxy-nav-bar__center {
 /* prettier-ignore */
 font-size: 17PX;
 /* prettier-ignore */
 line-height: 17PX;
 text-align: center;
 position: relative;
 flex: 1;
 display: -webkit-box;
 display: -webkit-flex;
 display: flex;
 align-items: center;
 justify-content: center;
 /* prettier-ignore */
 padding-left: 10PX;
 text {
  margin-top: -2px;
  font-size:34px;
  font-weight:550;
  line-height:44px;
 }
}
.lxy-nav-bar__inner .lxy-nav-bar__loading {
 font-size: 0;
}
.lxy-nav-bar__inner .lxy-nav-bar__loading .lxy-loading {
 margin-left: 0;
}
.lxy-nav-bar__inner .lxy-nav-bar__right {
 /* prettier-ignore */
 margin-right: 10PX;
}
.lxy-nav-bar__placeholder {
 height: var(--navBarHeight);
 background: #f8f8f8;
 position: relative;
 z-index: 50;
 visibility: hidden;
}

.lxy-nav-bar-search {
 width: 100%;
 height: 100%;
 display: flex;
 justify-content: center;
 align-items: center;
 width: 100%;
 /* prettier-ignore */
 height: 32PX;
 /* prettier-ignore */
 border-radius: 16PX;
 position: relative;
 background: #f6f6f6;
}

.lxy-nav-bar-search__input {
 height: 100%;
 display: flex;
 align-items: center;
 color: #999;
 /* prettier-ignore */
 font-size: 15PX;
 /* prettier-ignore */
 line-height: 15PX;
}
.lxy-nav-bar__inner .lxy-nav-bar__left .lxy-nav-bar__btn_goback {
 background-image: url("data:image/svg+xml;charset=utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='24' viewBox='0 0 12 24'%3E %3Cpath fill-opacity='.9' fill-rule='evenodd' d='M10 19.438L8.955 20.5l-7.666-7.79a1.02 1.02 0 0 1 0-1.42L8.955 3.5 10 4.563 2.682 12 10 19.438z'/%3E%3C/svg%3E");
}
.lxy-nav-bar__inner .lxy-nav-bar__left .lxy-nav-bar__btn_goback.white {
 background-image: url("data:image/svg+xml;charset=utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='24' viewBox='0 0 12 24'%3E %3Cpath fill-opacity='.9' fill-rule='evenodd' d='M10 19.438L8.955 20.5l-7.666-7.79a1.02 1.02 0 0 1 0-1.42L8.955 3.5 10 4.563 2.682 12 10 19.438z' fill='%23ffffff'/%3E%3C/svg%3E");
}
.lxy-nav-bar__inner .lxy-nav-bar__left .lxy-nav-bar__btn_gohome {
 background-image: url("data:image/svg+xml,%3Csvg t='1565752242401' class='icon' viewBox='0 0 1024 1024' version='1.1' xmlns='http://www.w3.org/2000/svg' p-id='4326' width='48' height='48'%3E%3Cpath d='M537.13744054-106.18008097999996c-12.56871953-12.56871953-31.42179957-12.56871953-50.27488108 0L28.10427953 195.46919964000006c-12.56871953 12.56871953-18.85308003 25.13744054-18.85308003 37.70616005l0 609.58292171c0 25.13744054 18.85308003 43.99052059 43.9905191 43.9905191l301.6492806 0c18.85308004 0 31.42179957-12.56871953 31.42180105-31.42179957l0-314.21800013c0-18.85308004 12.56871953-31.42179957 31.42179956-31.42180105l188.53080038 0c18.85308004 0 31.42179957 12.56871953 31.42179956 31.42180105l0 314.21800013c0 18.85308004 12.56871953 31.42179957 31.42180105 31.42179957L970.7582814 886.7488005c25.13744054 0 43.99052059-18.85308003 43.9905191-43.9905191L1014.7488005 233.17535969000005c0-12.56871953-6.2843605-25.13744054-18.85308003-37.70616005l-458.75827993-301.64928062z' fill='%23000000' p-id='4327'%3E%3C/path%3E%3C/svg%3E");
 /* prettier-ignore */
 background-size: 17PX 34PX;
 margin-top: 10px;
}
.lxy-nav-bar__inner .lxy-nav-bar__left .lxy-nav-bar__btn_gohome.white {
 background-image: url("data:image/svg+xml,%3Csvg t='1565752242401' class='icon' viewBox='0 0 1024 1024' version='1.1' xmlns='http://www.w3.org/2000/svg' p-id='4326' width='48' height='48'%3E%3Cpath d='M537.13744054-106.18008097999996c-12.56871953-12.56871953-31.42179957-12.56871953-50.27488108 0L28.10427953 195.46919964000006c-12.56871953 12.56871953-18.85308003 25.13744054-18.85308003 37.70616005l0 609.58292171c0 25.13744054 18.85308003 43.99052059 43.9905191 43.9905191l301.6492806 0c18.85308004 0 31.42179957-12.56871953 31.42180105-31.42179957l0-314.21800013c0-18.85308004 12.56871953-31.42179957 31.42179956-31.42180105l188.53080038 0c18.85308004 0 31.42179957 12.56871953 31.42179956 31.42180105l0 314.21800013c0 18.85308004 12.56871953 31.42179957 31.42180105 31.42179957L970.7582814 886.7488005c25.13744054 0 43.99052059-18.85308003 43.9905191-43.9905191L1014.7488005 233.17535969000005c0-12.56871953-6.2843605-25.13744054-18.85308003-37.70616005l-458.75827993-301.64928062z' fill='%23ffffff' p-id='4327'%3E%3C/path%3E%3C/svg%3E");
 /* prettier-ignore */
 background-size: 17PX 34PX;
 margin-top: 10px;
}
.lxy-nav-bar-search__icon {
 /* prettier-ignore */
 width: 22PX;
 /* prettier-ignore */
 height: 22PX;
 display: flex;
 align-items: center;
 justify-content: center;
 background-image: url("data:image/svg+xml,%3Csvg t='1565691512239' class='icon' viewBox='0 0 1024 1024' version='1.1' xmlns='http://www.w3.org/2000/svg' p-id='1240' width='48' height='48'%3E%3Cpath d='M819.2 798.254545L674.909091 653.963636c46.545455-48.872727 74.472727-114.036364 74.472727-186.181818 0-151.272727-123.345455-274.618182-274.618182-274.618182-151.272727 0-274.618182 123.345455-274.618181 274.618182 0 151.272727 123.345455 274.618182 274.618181 274.618182 65.163636 0 128-23.272727 174.545455-62.836364l144.290909 144.290909c2.327273 2.327273 6.981818 4.654545 11.636364 4.654546s9.309091-2.327273 11.636363-4.654546c6.981818-6.981818 6.981818-18.618182 2.327273-25.6zM235.054545 467.781818c0-132.654545 107.054545-239.709091 239.709091-239.709091 132.654545 0 239.709091 107.054545 239.709091 239.709091 0 132.654545-107.054545 239.709091-239.709091 239.709091-132.654545 0-239.709091-107.054545-239.709091-239.709091z' fill='%23999999' p-id='1241'%3E%3C/path%3E%3C/svg%3E");
 background-repeat: no-repeat;
 background-size: cover;
}
input{
  padding:0 20px !important;
  text-align: start !important;
}