反应原生模式始终可见

Question

我试图在 React Native 中单击按钮时显示模态。最初模式状态是隐藏的，点击按钮模式应该显示。

但现在每次都是可见的。

//Login.tsx

import React, { Component } from 'react';
import { StyleSheet, Text, View, Image, TextInput, Button, TouchableOpacity, ScrollView } from 'react-native';
import axios from 'axios';
import InvalidUserModal from '../Modal/InvalidUser';

export default class LoginFirst extends Component {
constructor(props) {
    super(props);

    this.state = {
        modalVisible: false
    };
}

triggerModal() {
    this.setState(prevState => {
      return {
        modalVisible: true
      }
    });
 }

render() {
    return (
        <View style={styles.container}>
            <Button 
                onPress = {() => this.triggerModal()}
                title = "Open Modal"
                color = "orange">
            </Button>
            <InvalidUserModal 
                image = '../../../../assets/user.png'
                data = 'Krunal'
                display = { this.state.modalVisible }
            />
         </View>
      );
    }
}

const styles = StyleSheet.create({
container: {
    flex: 1,
    backgroundColor: '#0d2c4f',
    justifyContent: 'center'
}
});

模态内容

import React, { Component } from 'react';
import { Modal, View, Image, Text, StyleSheet } from 'react-native';

const InvalidUser = (props) => (
<View>
    <Modal
        visible={props.display}
        animationType={'slide'}
        onRequestClose={() => console.log('closed')}
    >
        <View>
            <Image
                source={props.image} 
                style={styles.image}
            />
            <Text style={ styles.text}>
                {props.data}
            </Text>
        </View>
    </Modal>
</View>
);

const styles = StyleSheet.create({
image: {
    marginTop: 20,
    marginLeft: 90,
    height: 200,
    width: 200
},
text: {
    fontSize: 20,
    marginLeft: 150
}
});

export default InvalidUser;

上面的代码工作正常。唯一的问题是模态总是显示。从不隐藏。请看下面的屏幕。

代码中还有什么要做的吗。真的卡在这里了。

Answer 1

我不确定这是否有效，但这里有一些你应该尝试的事情。

从View​Modal

const InvalidUser = (props) => (
{// <View> removed }
    <Modal
        visible={props.display}
        animationType="slide" {// you don't need {} if it's a string}
        onRequestClose={() => console.log('closed')}
    >
        <View>
            <Image
                source={props.image} 
                style={styles.image}
            />
            <Text style={ styles.text}>
                {props.data}
            </Text>
        </View>
    </Modal>
{// </View> removed }
);

setState以更好的方式

如果您只想将状态设置为true，则不需要知道prevState。

// inside triggerModal 
this.setState({modalVisible: true});

对类属性使用箭头函数并避免多次渲染箭头函数。

// arrow function
triggerModal = () => {
    this.setState({modalVisible: true});
}

render() {
    return (
        <View style={styles.container}>
            <Button 
                {// avoid creating a new function on every render }
                onPress = {this.triggerModal}
                title = "Open Modal"
                color = "orange">
            </Button>
            <InvalidUserModal 
                image = '../../../../assets/user.png'
                data = 'Krunal'
                display = { this.state.modalVisible }
            />
         </View>
      );
    }
}