废话不多说先来看看效果:
1.前言
最近公司有一个新需求。有子项的能展开与收缩,没有子项的之前显示主项。显示主项FlatList这个总所周知。但是在这里面展开与收缩,代码不难写,但是性能方面呢,要不就是卡顿要么就是隐隐约约的延迟效果。有好多人也尝试用SectionList,本人也尝试过,但是还是出现卡顿与延迟。在github,以及开源中国上,google上查了一遍,跑了很多人写的demo,都存在这个问题。废话不多说开始看代码
2.解决问题的关键
关键在于展开与收缩的实现,平常的写代码,或者加动画,也不能完全掩盖性能的问题。通过在github上查阅react-native-ui的开源库,找到了native-base这个库,地址:https://github.com/GeekyAnts/NativeBase。通过查阅组建库,发现了一个叫Accordion这个控件,发现展开与收缩,效果极佳,性能优越。
紧接着,通过FlatList中的renderRow方法让每一项都是Accordion,是不是效果就能实现。
通过尝试,目前已经得以解决,至于这个Accordion的header与content,则可以通过Accordion的renderHeader和renderContent进行自定义。
3.需求解决
需求一:列表分组展开收缩卡顿问题解决
需求二:有子item的展示,没有的显示header,代码逻辑自己书写,这个不难实现吧。
4.完整代码
/**
* Sample React Native App
* https://github.com/facebook/react-native
* @flow
*/
import React, {Component}from 'react';
import {Image, TouchableOpacity}from 'react-native'
import {Container, Header, Content, Accordion, View, Text, Icon, List, ListItem}from 'native-base'
const dataArray = [
{"title":"测试-1", children: []},
{
"title":"测试-2", children: [
{"title":"一层"},
{"title":"二层"},
]
},
{
"title":"测试-3", children: [
{"title":"一层"},
{"title":"二层"},
]
},
{
"title":"测试-4", children: [
{"title":"一层"},
{"title":"二层"},
]
},
{
"title":"测试-5", children: [
{"title":"一层"},
{"title":"二层"},
]
},
{
"title":"测试-6", children: [
{"title":"一层"},
{"title":"二层"},
]
},
{
"title":"测试-7", children: [
{"title":"一层"},
{"title":"二层"},
]
},
{
"title":"测试-8", children: [
{"title":"一层"},
{"title":"二层"},
]
},
{
"title":"测试-8", children: [
{"title":"一层"},
{"title":"二层"},
]
},
{"title":"测试-1", children: []},
{
"title":"测试-2", children: [
{"title":"一层"},
{"title":"二层"},
]
},
{
"title":"测试-3", children: [
{"title":"一层"},
{"title":"二层"},
]
},
{
"title":"测试-4", children: [
{"title":"一层"},
{"title":"二层"},
]
},
{
"title":"测试-5", children: [
{"title":"一层"},
{"title":"二层"},
]
},
{
"title":"测试-6", children: [
{"title":"一层"},
{"title":"二层"},
]
},
{
"title":"测试-7", children: [
{"title":"一层"},
{"title":"二层"},
]
},
{
"title":"测试-8", children: [
{"title":"一层"},
{"title":"二层"},
]
},
{
"title":"测试-8", children: [
{"title":"一层"},
{"title":"二层"},
]
}
]
export default class Appextends Component<{}> {
_renderHeader(item, expanded) {
if (item.children.length ==0) {
return (
height:40, flexDirection:'row', alignItems:'center', borderBottomWidth:1, borderBottomColor:'#D7D7D7', paddingLeft:0 }}> style={{width:32, height:32}}/> style={{width:20, height:20, position:'absolute', right:6}}/> ) }else { return ( height:40, flexDirection:'row', alignItems:'center', borderBottomWidth:1, borderBottomColor:'#D7D7D7', paddingLeft:6 }}> style={{width:20, height:20}}/> ) } } _renderContent(rowItem) { return ( height:40, flexDirection:'row', alignItems:'center', borderBottomWidth:1, borderBottomColor:'#D7D7D7', paddingLeft:20 }}> style={{width:32, height:32}}/> style={{width:20, height:20, position:'absolute', right:6}}/> }/> ) } render() { return ( }/> ); } } 5.总结 这是目前个人觉得完美的实现,采纳的攻城狮门,麻烦点赞。谢谢