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React Native实现进度条弹框的示例代码

2019-11-19 16:03:57
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本文介绍了React Native实现进度条弹框,分享给大家

我们在上传或者下载文件时候,希望有一个进度条弹框去提醒用户取当前正在上传或者下载,也允许用去取点击取消上传或者下载。

首先实现进度条。

import React, {  PureComponent} from 'react';import {  StyleSheet,  View,  Animated,  Easing,} from 'react-native';class Bar extends PureComponent {  constructor(props) {    super(props);    this.progress = new Animated.Value(this.props.initialProgress || 0);  }  static defaultProps = {    style: styles,    easing: Easing.inOut(Easing.ease)  }  componentWillReceiveProps(nextProps) {    if (this.props.progress >= 0 && this.props.progress !== nextProps.progress) {      this.update(nextProps.progress);    }  }  shouldComponentUpdate() {    return false;  }  update(progress) {    Animated.spring(this.progress, {      toValue: progress    }).start();  }  render() {    return (      <View style={[styles.background, this.props.backgroundStyle, this.props.style]}>        <Animated.View style={[styles.fill, this.props.fillStyle, { width: this.progress.interpolate({          inputRange: [0, 100],          outputRange: [0 * this.props.style.width, 1 * this.props.style.width],          })} ]}        />      </View>    );  }}var styles = StyleSheet.create({  background: {    backgroundColor: '#bbbbbb',    height: 5,    overflow: 'hidden'  },  fill: {    backgroundColor: 'rgba(0, 122, 255, 1)',    height: 5  }});export default Bar;

进度条的值我们用动画实现,避免使用state不断去重新render渲染界面,同时设置shouldComponentUpdate返回值为false,避免重新render。

实现进度条弹框。

import React, {  PropTypes,  PureComponent} from 'react';import {  View,  StyleSheet,  Modal,  Text,  Dimensions,  TouchableOpacity} from 'react-native';import Bar from './Bar';const {  width} = Dimensions.get('window');class ProgressBarDialog extends PureComponent {  constructor(props) {    super(props);  }  static propTypes = {    ...Modal.propTypes,    title: PropTypes.string,    canclePress: PropTypes.func,    cancleText: PropTypes.string,    needCancle: PropTypes.bool  };  static defaultProps = {    animationType: 'none',    transparent: true,    progressModalVisible: false,    onShow: () => {},    onRequestClose: () => {},    onOutSidePress: () => {},    title: '上传文件',    cancleText: '取消是',    canclePress: () => {},    needCancle: true  }  render() {    const {      animationType,      transparent,      onRequestClose,      progress,      title,      canclePress,      cancleText,      needCancle,      progressModalVisible    } = this.props;    return (      <Modal        animationType={animationType}        transparent={transparent}        visible={progressModalVisible}        onRequestClose={onRequestClose}>        <View style={styles.progressBarView}>          <View style={styles.subView}>            <Text style={styles.title}>              {title}            </Text>            <Bar              ref={this.refBar}              style={{marginLeft: 10,marginRight: 10,width:width - 80}}              progress={progress}              backgroundStyle={styles.barBackgroundStyle}            />            <View style={styles.progressContainer}>              <Text style={styles.progressLeftText}>                {`${progress}`}%              </Text>              <Text style={styles.progressRightText}>                {`${progress}`}/100              </Text>            </View>            {needCancle &&              <View style={styles.cancleContainer}>                <TouchableOpacity style={styles.cancleButton} onPress={canclePress}>                  <Text style={styles.cancleText}>                    {cancleText}                  </Text>                </TouchableOpacity>              </View>            }          </View>        </View>      </Modal>    );  }}const styles = StyleSheet.create({  progressBarView: {    flex:1,    justifyContent: 'center',    alignItems: 'center',    backgroundColor: 'rgba(0,0,0,0.2)'  },  barStyle: {    marginLeft: 10,    marginRight: 10,    width:width - 80  },  progressLeftText: {    fontSize: 14  },  cancleContainer: {    justifyContent: 'center',    alignItems: 'flex-end'  },  progressRightText: {    fontSize: 14,    color: '#666666'  },  barBackgroundStyle: {    backgroundColor: '#cccccc'  },  progressContainer: {    flexDirection: 'row',    padding: 10,    justifyContent: 'space-between'  },  subView: {    marginLeft: 30,    marginRight: 30,    backgroundColor: '#fff',    alignSelf: 'stretch',    justifyContent: 'center'  },  progressView: {    flexDirection: 'row',    padding: 10,    paddingBottom: 5,    justifyContent: 'space-between'  },  title: {    textAlign: 'left',    padding:10,    fontSize: 16  },  cancleButton: {    padding:10  },  cancleText: {    textAlign: 'right',    paddingTop: 0,    fontSize: 16,    color: 'rgba(0, 122, 255, 1)'  }});export default ProgressBarDialog;

props

  1. modal的props - 这些都是modal的属性
    1. animationType - 动画类型
    2. transparent - 是否透明
    3. progressModalVisible - 是否可见
    4. onShow - 弹框出现
    5. onRequestClose - 弹框请求消失(比如安卓按返回键会触发这个方法)
  2. onOutSidePress - 点击弹框外部动作
  3. title - 弹框的标题
  4. cancleText - 取消的文字
  5. canclePress - 取消动作
  6. needCancle - 是否需要取消按钮

使用代码

import React , {  PureComponent} from 'react';import {  View} from 'react-native';import ProgressBarDialog from './ProgressBarDialog';class Upload extends PureComponent {  constructor(props) {    this.state = {      progress: 0,      progressModalVisible: false    };  }  refProgressBar = (view) => {    this.progressBar = view;  }  showProgressBar = () => {    this.setState({      progressModalVisible: true    });  }  dismissProgressBar = () => {    this.setState({      progress: 0,      progressModalVisible: false    });  }  setProgressValue = (progress) => {    this.setState({      progress    });  }  onProgressRequestClose = () => {    this.dismissProgressBar();  }  canclePress = () => {    this.dismissProgressBar();  }  render() {    return (      <View>        <ProgressBarDialog          ref={this.refProgressBar}          progress={this.state.progress}          progressModalVisible={this.state.progressModalVisible}          onRequestClose={this.onProgressRequestClose}          canclePress={this.canclePress}          needCancle={true}        />      </View>    )  }}export default Upload;

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武林网。

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