在开发 App 的时候，经常会使用到对话框（又叫消息框、提示框、告警框）。 在web开发中经常会用得到。今天就来介绍了一下react-native 封装弹出框

之前看到react-native-image-picker中自带了一个选择器，可以选择拍照还是图库，但我们的项目中有多处用到这个选择弹出框，所以就自己写了一下，最最重要的是ios和Android通用。先上动态效果图~

一、封装要点

1.使用动画实现弹框布局及显示隐藏效果

2.通过一个boolean值控制组件的显示隐藏

3.弹框选项数组通过调用的js传到弹框组件

4.组件选项的字体颜色通过调用js传到组件，实现可拓展；

5.选择选项回调方法

二、代码实现

新建alertSelected.js

/** * Created by sybil052 on 2017/6/19. */import React, {Component} from 'react';import { StyleSheet, View, Image, Text, TouchableHighlight, Animated, Easing, Dimensions, Platform, TouchableOpacity} from 'react-native';const {width, height} = Dimensions.get('window');const [aWidth] = [width-20];const [left, top] = [0, 0];const [middleLeft] = [(width - aWidth) / 2];export default class AlertSelected extends Component { constructor(props) { super(props); this.state = { offset: new Animated.Value(0), opacity: new Animated.Value(0), title: "", choose0: "", choose1: "", hide: true, tipTextColor: '#333333', aHeight: 236, }; this.entityList = [];//数据源 this.callback = function () { };//回调方法 } render() { if (this.state.hide) { return (<View />) } else { return ( <View style={styles.container}> <Animated.View style={styles.mask}> </Animated.View> <Animated.View style={[{ width: aWidth, height: this.state.aHeight, left: middleLeft, ...Platform.select({ ios:{ bottom: - 20, }, }), alignItems: "center", justifyContent: "space-between", }, { transform: [{ translateY: this.state.offset.interpolate({ inputRange: [0, 1], outputRange: [height, (height - this.state.aHeight - 34)] }), }] }]}> <View style={styles.content}> <View style={styles.tipTitleView}> <Text style={styles.tipTitleText}>{this.state.title}</Text> </View> { this.entityList.map((item, i) => this.renderItem(item, i)) } </View> <TouchableHighlight style={styles.button} underlayColor={'#f0f0f0'} onPress={this.cancel.bind(this)} > <Text style={styles.buttonText}>取消</Text> </TouchableHighlight> </Animated.View> </View> ); } } renderItem(item, i) { return ( <View style={styles.tipContentView}> <View style={{height: 0.5, backgroundColor: '#a9a9a9', width: aWidth}}/> <TouchableOpacity key={i} onPress={this.choose.bind(this, i)} > <View style={styles.item}> <Text style={{ color: this.state.tipTextColor, fontSize: 17, textAlign: "center", }}>{item}</Text> </View> </TouchableOpacity> </View> ); } componentDidMount() { } componentWillUnmount() { // 如果存在this.timer，则使用clearTimeout清空。 // 如果你使用多个timer，那么用多个变量，或者用个数组来保存引用，然后逐个clear this.timer && clearTimeout(this.timer); this.chooseTimer && clearTimeout(this.chooseTimer); } //显示动画 in() { Animated.parallel([ Animated.timing( this.state.opacity, { easing: Easing.linear,//一个用于定义曲线的渐变函数 duration: 200,//动画持续的时间（单位是毫秒），默认为200。 toValue: 0.8,//动画的最终值 } ), Animated.timing( this.state.offset, { easing: Easing.linear, duration: 200, toValue: 1, } ) ]).start(); } //隐藏动画 out() { Animated.parallel([ Animated.timing( this.state.opacity, { easing: Easing.linear, duration: 200, toValue: 0, } ), Animated.timing( this.state.offset, { easing: Easing.linear, duration: 200, toValue: 0, } ) ]).start((finished) => this.setState({hide: true})); } //取消 cancel(event) { if (!this.state.hide) { this.out(); } } //选择 choose(i) { if (!this.state.hide) { this.out(); this.chooseTimer = setTimeout(()=>{ this.callback(i); }, 200); } } /** * 弹出控件，最多支持3个选项(包括取消) * titile: 标题 * entityList：选择项数据 数组 * tipTextColor: 字体颜色 * callback：回调方法 */ show(title: string, entityList: Array, tipTextColor: string, callback: Object) { this.entityList = entityList; this.callback = callback; if (this.state.hide) { if (entityList && entityList.length > 0) { let len = entityList.length; if (len === 1) { this.setState({title: title, choose0: entityList[0], hide: false, tipTextColor: tipTextColor, aHeight: 180}, this.in); } else if (len === 2) { this.setState({title: title, choose0: entityList[0], choose1: entityList[1], hide: false, tipTextColor: tipTextColor, aHeight: 236}, this.in); } } } }}const styles = StyleSheet.create({ container: { position: "absolute", width: width, height: height, left: left, top: top, }, mask: { justifyContent: "center", backgroundColor: "#000000", opacity: 0.3, position: "absolute", width: width, height: height, left: left, top: top, }, // 提示标题 tipTitleView: { height: 56, flexDirection: 'row', alignItems: 'center', justifyContent: 'center', backgroundColor: '#fff', marginLeft: 10, marginRight: 10 }, // 提示文字 tipTitleText: { color: "#999999", fontSize: 14, }, // 分割线 tipContentView: { width: aWidth, height: 56, backgroundColor:'#fff', borderBottomLeftRadius: 5, borderBottomRightRadius: 5, }, item:{ width: aWidth, height: 56, backgroundColor:'#fff', justifyContent: 'center', borderRadius: 5, }, button: { height: 57, backgroundColor: '#fff', alignSelf: 'stretch', justifyContent: 'center', borderRadius: 5, }, // 取消按钮 buttonText: { fontSize: 17, color: "#0084ff", textAlign: "center", }, content: { backgroundColor: '#fff', borderRadius: 5, }});

三、使用方法

新建demo.js

const selectedArr = ["拍照", "图库"];class Demo extends Component { constructor(props) { super(props); this.showAlertSelected = this.showAlertSelected.bind(this); this.callbackSelected = this.callbackSelected.bind(this); } showAlertSelected(){ this.dialog.show("请选择照片", selectedArr, '#333333', this.callbackSelected); } // 回调 callbackSelected(i){ switch (i){ case 0: // 拍照 this.takePhoto(); break; case 1: // 图库 this.pickMultiple(); break; } } render() { return ( <View style={stylesCommon.container}> <TouchableOpacity onPress={() => {this.showAlertSelected();}}> <View style={styles.imageBorder}> <Text style={styles.photoText}></Text> </View> </TouchableOpacity> <DialogSelected ref={(dialog)=>{ this.dialog = dialog; }} /> </View> ); } }

再来一张其他界面调用该组件的效果图~

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。