如何在课堂组件中使用react导航道具?

时间:2018-10-18 16:37:05

标签: javascript reactjs react-native

我创建了一个共享图标,该图标会在社交帐户(如facebook,whatsapp,gmail等)上点击共享的pdf或图像文件时显示。我想在类组件内部传递可共享文件的URL链接,但出现错误。如果我对URL进行硬编码,则可以正常工作,但是如何传递从React导航中收到的URL?

工作代码:

    import React, { Component } from 'react';
    import { Share, View, TouchableOpacity } from 'react-native';
import Icon from 'react-native-vector-icons/Ionicons';

    const shareOptions = {
        title: 'Download Brochure',
        url: 'https://cpbook.propstory.com/upload/project/brochure/5bc58ae6ca1cc858191327.pdf'
    }

    export default class Screen extends Component {

    onSharePress = () => Share.share(shareOptions);

    render() {
     return (
    <View> 
    <Text style={styles.infoTitle}>Share: </Text>
                            <TouchableOpacity onPress={this.onSharePress}>
                                <Icon style={{paddingLeft: 10, paddingTop: 10}}name="md-share" size={30} color="black"/>
                            </TouchableOpacity>
    </View>
    }

    }

上面的代码可以正常工作,但是下面的代码给出错误,提示未定义shareOptions。我该如何克服这个问题?我想在shareOptions内传递文件URL。我正在从反应导航道具(即brochure)中获取文件网址。

代码:

import React, { Component } from 'react';
import { Share, View, TouchableOpacity } from 'react-native';
import Icon from 'react-native-vector-icons/Ionicons';

export default class Screen extends Component {

onSharePress = () => Share.share(shareOptions);  <---Getting error here shareOptions undefined

render() {

const project = this.props.navigation.getParam('project', null);

let { brochure } = project;

const shareOptions = {
  title: 'Download Brochure',
  url: brochure
}

return (
<View> 
<Text style={styles.infoTitle}>Share: </Text>
                        <TouchableOpacity onPress={this.onSharePress}>
                            <Icon style={{paddingLeft: 10, paddingTop: 10}}name="md-share" size={30} color="black"/>
                        </TouchableOpacity>
</View>
)

}

如何克服上述问题以及如何传递道具,即在上述情况下,文件URL属于brochure道具中。

2 个答案:

答案 0 :(得分:1)

您没有将shareOptions传递给您的share方法,因此它是未定义的。

您可以通过多种方式重构代码,下面可以看到一种更可行的方法。

由于您的渲染函数未使用return语句上方的任何逻辑,因此我只是将所有这些迁移到了onSharePress函数中,自然如果它们不同,那么您将希望通过参数将其传递。

export default class Screen extends Component {

    onSharePress = () => {

        const project = this.props.navigation.getParam('project', null);

        let { brochure } = project;

        const shareOptions = {
            title: 'Download Brochure',
            url: brochure
        }

        Share.share(shareOptions);
    } 

    render() {

        return (
            <View> 
                <Text style={styles.infoTitle}>Share: </Text>
                <TouchableOpacity onPress={this.onSharePress>
                    <Icon style={{paddingLeft: 10, paddingTop: 10}}name="md-share" size={30} color="black"/>
                </TouchableOpacity>
            </View>
        )

    }
}

答案 1 :(得分:1)

只需将shareOptions对象作为参数传递给onSharePress函数,并在onSharePress事件处理程序函数中获取shareOptions

import React, { Component } from 'react';
import { Share, View, TouchableOpacity } from 'react-native';
import Icon from 'react-native-vector-icons/Ionicons';

export default class Screen extends Component {

   onSharePress = (shareOptions) => {
      Share.share(shareOptions);  
   }

   render() {
      const { navigation } = this.props;
      const project = navigation.getParam('project', null);
      const { brochure } = project;
      const shareOptions = {
         title: 'Download Brochure',
         url: brochure
      }

   return (
     <View> 
       <Text style={styles.infoTitle}>Share: </Text>
         <TouchableOpacity onPress={() => this.onSharePress(shareOptions)}>
            <Icon style={{paddingLeft: 10, paddingTop: 10}}name="md-share" size={30} color="black"/>
         </TouchableOpacity>
     </View>
   )
  }
}