react native 之ScrollView下拉刷新

 1 import React,{Component} from ‘react‘;
 2 import {
 3     View,
 4     Text,
 5     StyleSheet,
 6     ScrollView,
 7     RefreshControl,
 8     Dimensions
 9 } from ‘react-native‘;
10 
11 const screenW=Dimensions.get(‘window‘).width;
12 
13 export default class CKRefresh extends Component{
14     constructor(){
15         super();
16         this.state={
17             rowDataArr:Array.from(new Array(30)).map((value,index)=>({
18                 title:‘初始化数据‘+index
19             })),
20             //是否显示loading
21             isRefreshing:false,
22             loaded:0
23         }
24     }
25 
26     render(){
27         const rowsArr=this.state.rowDataArr.map((row,index)=>(<Row data={row} key={index}/>))
28         return(
29             <ScrollView
30                 refreshControl={
31                     <RefreshControl
32                         refreshing={this.state.isRefreshing}
33                         onRefresh={()=>this._onRefresh()}
34                         colors={[‘red‘,‘green‘,‘blue‘]}
35                         title="正在加载中..."
36                     />
37                 }
38             >
39                 {rowsArr}
40             </ScrollView>
41         )
42     }
43 
44     _onRefresh(){
45         //1.显示指示器
46         this.setState({
47             isRefreshing:true
48         });
49         //2.模拟加载数据
50         setTimeout(()=>{
51             let newDataArr=Array.from(new Array(5)).map((value,index)=>({
52                 title:‘我是拉下来的数据‘+(this.state.loaded+index)
53             })).concat(this.state.rowDataArr);
54             //更新状态机
55             this.setState({
56                 rowDataArr:newDataArr,
57                 isRefreshing:false,
58                 loaded:this.state.loaded+5
59             });
60         },2000);
61     }
62 }
63 
64 class Row extends Component{
65     static defaultProps={
66         data:{}
67     };
68     render(){
69         return(
70             <View style={{
71                 width:screenW,
72                 height:40,
73                 borderBottomWidth:1,
74                 borderBottomColor:‘red‘,
75                 justifyContent:‘center‘
76             }}>
77                 <Text>{this.props.data.title}</Text>
78             </View>
79         )
80     }
81 }
82 
83 const styles=StyleSheet.create({
84 
85 })

 1 /**
 2  * Sample React Native App
 3  * https://github.com/facebook/react-native
 4  *
 5  * @format
 6  * @flow strict-local
 7  */
 8 
 9 import React from ‘react‘;
10 import {
11   SafeAreaView,
12   StyleSheet,
13   ScrollView,
14   View,
15   Text,
16   StatusBar,
17 } from ‘react-native‘;
18 
19 import {
20   Header,
21   LearnMoreLinks,
22   Colors,
23   DebugInstructions,
24   ReloadInstructions,
25 } from ‘react-native/Libraries/NewAppScreen‘;
26 
27 import CKRefresh from ‘./components/CKRefresh‘;
28 const App: () => React$Node = () => {
29 
30   return (
31     <>
32       <StatusBar barStyle="dark-content" />
33       <SafeAreaView style={styles.mainViewStyle}>
34       <CKRefresh/>
35       </SafeAreaView>
36     </>
37   );
38 };
39 
40 
41 const styles=StyleSheet.create({
42   mainViewStyle:{
43       flex:1,
44       backgroundColor:‘#fff‘,
45   }
46 });
47 
48 
49 
50 export default App;