我试图通过对表达式进行检查来验证用户的电子邮件.但我得到的结果对所有条目都无效.
更新的代码
class dummytest extends Component{
constructor(props){
super(props);
this.state = {
email :'',
validated: false ,
}
};
go = () => {
const reg = /^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/;
if (reg.test(this.state.email) === true){
alert( valid);
}
else{
alert();
}
}
render(){
return(
<View style={{alignSelf:'center',marginTop:100}}>
<TextInput autoCapitalize="none" autoCorrect={false} style={{height:20,width:200,backgroundColor:'blue'}} value={this.setState.email}/>
<Button onPress={this.go.bind(this)}>
<Text> GO </Text>
</Button>
</View>
);
}
}
Run Code Online (Sandbox Code Playgroud) 当我试图为每次按下按钮时设置计数时,我面临上述错误.
export default class ViewIdeas extends Component{
get InitialState(){
return {
count : 0
}
}
render(){
return(
.......
<Button transparent>
<Icon name='ios-thumbs-up-outline' style={{fontSize:21}}
onPress={() => this.setState({count: ++this.state.count})}/>
<Text>{'Like' + this.state.count}</Text>
</Button>
Run Code Online (Sandbox Code Playgroud) 当我按下按钮时,它应该导航到另一个页面,它也会增加查看次数.
但我无论如何都无法理解同时实施它们.
这是我的代码:
<Button onPress={Actions.ideaOnClick}>
<Button onPress={() => this.setState({views: ++this.state.views})}>
Run Code Online (Sandbox Code Playgroud) button react-native react-native-android react-native-ios react-navigation
我正在尝试使用 react-native-image-crop-picker。代码如下。我已经尝试过 npm install react-native-image-crop-picker@latest。
每当我选择任何一个未定义的选项时,都不会显示对象(正在评估“imagePicker.openPicker”)。请帮助解决这个问题。
import React, {Component} from 'react';
import {
View, Text, StyleSheet, ScrollView, Alert,
Image, TouchableOpacity, NativeModules, Dimensions
} from 'react-native';
var ImagePicker = NativeModules.ImageCropPicker;
const styles = StyleSheet.create({
container: {
flex: 1,
justifyContent: 'center',
alignItems: 'center'
},
button: {
backgroundColor: 'blue',
marginBottom: 10
},
text: {
color: 'white',
fontSize: 20,
textAlign: 'center'
}
});
export default class Upload extends Component {
constructor() {
super();
this.state = {
image: null,
images: null
};
}
pickSingleWithCamera(cropping) { …Run Code Online (Sandbox Code Playgroud)