react-native-scrolltotop

a RN component make list come back to top.

IOS && ANDROID

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Installation

npm install --save react-native-scrolltotop

Usage example

see the example/example.js for a more detailed example.

import ScrollTopView from 'react-native-scrolltotop';

  //first set default state in your constructor
  constructor(props) {
    //...
    this.state = {
      isShowToTop: false,
    };
  }
  
  //then bind a method to detect the scroll distance of your listView
  //set ref with 'listview'
  <ListView
        ref="listview"
        onScroll={(e)=>this._onScroll(e)} 
        style={styles.listView} 
        renderScrollComponent={(props)=>{
            return <ScrollView style={styles.ViewPort} {...props}/>
        }}/>
  
  //here is the _onScrol method
  _onScroll(e) {
    var offsetY = e.nativeEvent.contentOffset.y;

    if(offsetY > 100) {
        this.setState({
            isShowToTop: true
        })
    } else {
        this.setState({
            isShowToTop: false
        })
    }
  }

//use it with your listView together
  <View style={{flex:1}}>
    <View style={styles.header}>
      <Text style={styles.headerText}>消息列表</Text>
    </View>
    {listView}
    {this.state.isShowToTop?<ScrollTopView root={this} ></ScrollTopView>:null}
  </View>

Props

Prop	Type	Optional	Default	Description
root		require		current component
width	number	Yes	60	use in both the button and the image if you have
height	number	Yes	60	use in both the button and the image if you have
bgColor	string	Yes	'#099fde'	backgroundColor of button，
isRadius	bool	Yes	true	whether need a borderRadius of your button
bdRadius	number	Yes	30	borderRadius of your button
left	number	Yes	Dimensions.get('window').width - 80	distance from the left
top	number	Yes	Dimensions.get('window'.height - 160	distance from the top

use Text

Prop	Type	Optional	Default	Description
color	string	Yes	'#ffffff'	color of your text
fontSize	number	Yes	12	fontSize of your text

use Image

Prop	Type	Optional	Default	Description
width	number	Yes	60	same with button
height	number	Yes	60	same with button
imageUri	string	Yes	a base64 img	uri of your Image

if it is useful to you, let me know 😄.