当 View 安装时,我希望辅助 View 离开屏幕到主视图的右侧。
当用户平移向左时,辅助 View 应该跟随平移并最终覆盖主视图。 (比如 Instagram 相机)
我已经设置了一个基本结构,但我不确定如何最终确定 <Animated.View>
部分。例如,我是将平移处理程序放在主视图还是辅助 View 上?我不希望辅助 View 覆盖主视图上的任何交互。
import React from 'react';
import { PanResponder, Animated, Dimensions, StyleSheet, Text, View } from 'react-native';
const winWidth = Dimensions.get('window').width
const winHeight = Dimensions.get('window').height
class Main extends React.Component {
constructor(props){
super(props);
}
translateX = new Animated.Value(0);
panResponder = PanResponder.create({
onMoveShouldSetPanResponderCapture: (e, gs) => {
return gs.dx < 0 //allow left only
},
onPanResponderMove: (e, gs) => {
if(gs.dx < 0) {
Animated.event([null, {dx: this.translateX}])(e, gs)
}
},
onPanResponderRelease: (e, {vx, dx}) => {
//Secondary View should now cover the main View
},
onPanResponderTerminationRequest: (e, gs) => {
return false
},
onPanResponderTerminate: (e, {vx, dx} ) => {
},
})
render(){
return(
<View style={{styles.main}}>
<View style={{styles.secondary}}></View>
<View><Text>Other components will be displayed</Text></View>
</View>
)
}
}
const styles = StyleSheet.create({
main:{
flex:1,
flexDirection:'column',
backgroundColor: '#ffffff'
},
secondary:{
width: winWidth,
height: winHeight,
backgroundColor: 'red',
position: 'absolute',
top:0,
left:winWidth, //start off screen
},
})
最佳答案
我不确定这是否是您想要的,但我的做法是在覆盖整个屏幕的 Animated.View 组件中嵌套两个 View 。
<Animated.View style={[this.position.getLayout(), {display: 'flex', flex: 1, flexDirection: 'row'}]} {...this.panResponder.panHandlers}>
<View style={{width: '100%', height: '100%', backgroundColor: 'yellow'}}>
<Text>
This is the Main view
</Text>
</View>
<View style={{ height: '100%', width: '100%', backgroundColor: 'red'}}>
<Text>
This is the invisible View
</Text>
</View>
</Animated.View>
Views 中的样式是让每一个覆盖整个宽度
在 Animated.View 中,我使用数组符号来应用两种样式
this.position.getLayout() 是给出 Animated.View 组件所在位置的坐标/位置的方法
另一个样式对象是这样我们就可以使用 flexbox 特别设置来渲染彼此相邻的 subview
还将 panHandlers 附加到 Animated.View
constructor(props){ super(props) position = new Animated.ValueXY() const panResponder = PanResponder.create({ onStartShouldSetPanResponder: ()=> true, onPanResponderMove: (evt, gesture)=>{ //Need to set theshhold and state.isOpen to determine direction here position.setValue({x: gesture.dx, y: 0}) }, onPanResponderGrant: ()=>{ this.position.setOffset({x: this.position.x._value, y: 0}) this.position.setValue({x: 0, y: 0}) }, onPanResponderRelease: ()=>{ this.openOrClose() } }) this.state = {isOpen: false} this.panResponder = panResponder this.position = position }
我使用 state 来监控 View 应该移动到 this.state = {isOpen: false} 的位置,具体取决于哪个 View 可见。
移动的函数主要是position.setValue({x: gesture.dx, y: 0}),它在触摸/平移仍处于事件状态时跟踪移动并且this.openOrClose() 释放触摸/平移时调用。
openOrClose 函数决定了如何处理移动,主要逻辑应该在这里。我只是做了一个简单的案例,并没有在这个例子中包含任何threshHold。
要了解 panHandlers,我建议您阅读 this article因为它解释了 onPanResponderGrant 最好的原因。
下面是工作组件的代码
import React, {Component} from 'react'
import {View, Text, Animated, PanResponder, Dimensions} from 'react-native'
const ScreenWidth = Dimensions.get('window').width
//Logic to flattenOffset required
export class Swipable extends Component{
constructor(props){
super(props)
position = new Animated.ValueXY()
const panResponder = PanResponder.create({
onStartShouldSetPanResponder: ()=> true,
onPanResponderMove: (evt, gesture)=>{
//Need to set theshhold and state.isOpen to determine direction here
position.setValue({x: gesture.dx, y: 0})
},
onPanResponderGrant: ()=>{
this.position.setOffset({x: this.position.x._value, y: 0})
this.position.setValue({x: 0, y: 0})
},
onPanResponderRelease: ()=>{
this.openOrClose()
}
})
this.state = {isOpen: false}
this.panResponder = panResponder
this.position = position
}
openOrClose = ()=>{
this.position.flattenOffset()
//determine where to move depending onState
direction = this.state.isOpen ? 0 : -ScreenWidth
Animated.spring(this.position, {
toValue: {x: direction, y: 0}
}).start(()=>{
//Callback when animation is complete to show if open or closed
this.setState((prevState)=>{
return {isOpen: !prevState.isOpen}
})
})
}
render(){
return(
<Animated.View style={[this.position.getLayout(), {display: 'flex', flex: 1, flexDirection: 'row'}]} {...this.panResponder.panHandlers}>
<View style={{width: '100%', height: '100%', backgroundColor: 'yellow'}}>
<Text>
This is the Main view
</Text>
</View>
<View style={{ height: '100%', width: '100%', backgroundColor: 'red'}}>
<Text>
This is the invisible View
</Text>
</View>
</Animated.View>
)
}
}
我在 Android 模拟器上运行了上面的代码,我相信它可以在 ios 上运行。如果有任何我需要澄清或改进的地方,请告诉我
关于ios - 如何让辅助 <View> 使用 PanResponder 进入主视图?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/53253709/