javascript - 无法使用 onChangeText 更新反应原生组件中的状态
问题描述
我一直在尝试更新提交表单时的电子邮件和密码值,以便我可以在我的登录 API 参数中传递它们。但是我几乎已经尝试了所有方法,它的值this.state
不会只是更新。每次我尝试在控制台日志中打印值时,例如:cosole.log(this.state.email)
,它都会打印空字符串,即先前设置的默认值。下面是我的代码:
login.js
import React, { Component } from 'react';
import { ThemeProvider, Button } from 'react-native-elements';
import BliszFloatingLabel from './BliszFloatingLabel'
import {
StyleSheet,
Text,
View,
Image,
TextInput,
Animated,
ImageBackground,
Linking
} from 'react-native';
const domain = 'http://1xx.xxx.xx.xxx:8000';
class Login extends Component {
state = {
email: '',
password: '',
}
LoginAPI = (e,p) => {
console.log(e, "####")
}
handleEmail = (text) => {
this.setState({ email: text })
}
handlePassword = (text) => {
this.setState({ password: text })
}
goToSignUpScreen=() =>{
this.props.navigation.navigate('SignUpScreen');
};
goToForgotPasswordScreen=() =>{
this.props.navigation.navigate('ForgotPasswordScreen');
};
render() {
return (
<View style={styles.container} >
<ImageBackground source={require('../bgrndlogin.jpeg')} style={styles.image} >
<View style={styles.heading}>
<Image style={styles.logo} source={require('../loginlogo.png')} />
<Text style={styles.logoText}>Login</Text>
<Text style={styles.logodesc}>Please Login to continue --></Text>
</View>
<View style={styles.form_container}>
<BliszFloatingLabel
label="Email Id"
value={this.state.email}
onChangeText = {this.handleEmail}
onBlur={this.handleBluremail}
/>
<BliszFloatingLabel
label="Password"
value={this.state.password}
onChangeText = {this.handlePassword}
onBlur={this.handleBlurpwd}
secureTextEntry={true}
/>
<ThemeProvider theme={theme}>
<Button buttonStyle={{
opacity: 0.6,
backgroundColor: '#CC2C24',
borderColor: 'white',
borderWidth: 1,
width: 200,
height: 50,
marginTop: 30,
marginLeft: '20%',
alignItems: 'center',
justifyContent: "center"
}}
title="Login"
type="outline"
onPress = {
() => this.LoginAPI(this.state.email, this.state.password)
}
/>
</ThemeProvider>
<Text style={{
marginTop: 70,
color: '#CC2C24',
fontSize: 16,
fontWeight: "bold"
}}
onPress={
this.goToForgotPasswordScreen
}>
Forgot Password?
</Text>
<Text style={{
marginTop: 20,
color: '#CC2C24',
fontSize: 16,
fontWeight: "bold"
}}
onPress={
this.goToSignUpScreen
}>
Don't have an Account?
</Text>
</View>
</ImageBackground>
</View>
)
}
}
const styles = StyleSheet.create({
container: {
flex: 1,
},
logo: {
width: 115,
height: 50,
},
logoText: {
color: 'white',
fontSize: 36,
fontWeight: "bold"
},
logodesc: {
color: '#CC2C24',
fontSize: 18,
fontWeight: "bold"
},
heading: {
flex: 3,
marginLeft:20,
marginTop:30
},
form_container: {
flex: 7,
marginLeft:20,
marginTop:30,
marginRight: 20,
},
image: {
flex: 1,
resizeMode: "cover",
justifyContent: "center"
},
});
const theme = {
Button: {
titleStyle: {
color: 'white',
fontWeight: "bold",
fontSize: 18
},
},
};
export default Login;
我创建了一个通用表单,如下所示,我到处继承:BliszFloatingLabel.js
import React, { Component } from 'react';
import {
Text,
View,
TextInput,
Animated,
} from 'react-native';
class BliszFloatingLabel extends Component {
state = {
entry: '',
isFocused: false,
};
UNSAFE_componentWillMount() {
this._animatedIsFocused = new Animated.Value(0);
}
handleInputChange = (inputName, inputValue) => {
this.setState(state => ({
...state,
[inputName]: inputValue // <-- Put square brackets
}))
}
handleFocus = () => this.setState({ isFocused: true })
handleBlur = () => this.setState({ isFocused: true?this.state.entry!='' :true})
handleValueChange = (entry) => this.setState({ entry });
componentDidUpdate() {
Animated.timing(this._animatedIsFocused, {
toValue: this.state.isFocused ? 1 : 0,
duration: 200,
useNativeDriver: true,
}).start();
}
render() {
// console.log(this.state.entry)
const { label, ...props } = this.props;
const { isFocused } = this.state;
const labelStyle = {
position: 'absolute',
left: 0,
top: !isFocused ? 40 : 0,
fontSize: !isFocused ? 16 : 12,
color: 'white',
};
return (
<View style={{ paddingTop: 20,paddingBottom:20 }}>
<Text style={labelStyle}>
{label}
</Text>
<TextInput
{...props}
style={{
height: 50, fontSize: 16, color: 'white', borderBottomWidth: 1, borderBottomColor: "white"
}}
value={this.state.entry}
onChangeText={this.handleValueChange}
onFocus={this.handleFocus}
onBlur={this.handleBlur}
blurOnSubmit
/>
</View>
)
}
}
export default BliszFloatingLabel;
解决方案
而不是像这样传递 onChangeText ,而是在组件onChangeText={this.handleValueChange}
中传递回调。BliszFloatingLabel
Login
onChangeText={(text)=>this.handleValueChange(text)}
小吃与夹具。
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