我定义了两个TextInput字段如下:
<TextInput
style = {styles.titleInput}
returnKeyType = {"next"}
autoFocus = {true}
placeholder = "Title" />
<TextInput
style = {styles.descriptionInput}
multiline = {true}
maxLength = {200}
placeholder = "Description" />
但在按下键盘上的“next”按钮后，我的react-native应用程序并没有跳转到第二个TextInput字段。我怎样才能做到呢?
谢谢!
当前回答
你不需要裁判也可以做到。这种方法是首选的，因为引用会导致脆弱的代码。React文档建议在可能的情况下寻找其他解决方案:
If you have not programmed several apps with React, your first inclination is usually going to be to try to use refs to "make things happen" in your app. If this is the case, take a moment and think more critically about where state should be owned in the component hierarchy. Often, it becomes clear that the proper place to "own" that state is at a higher level in the hierarchy. Placing the state there often eliminates any desire to use refs to "make things happen" – instead, the data flow will usually accomplish your goal.
相反，我们将使用一个状态变量来聚焦第二个输入字段。
Add a state variable that we'll pass as a prop to the DescriptionInput: initialState() { return { focusDescriptionInput: false, }; } Define a handler method that will set this state variable to true: handleTitleInputSubmit() { this.setState(focusDescriptionInput: true); } Upon submitting / hitting enter / next on the TitleInput, we'll call handleTitleInputSubmit. This will set focusDescriptionInput to true. <TextInput style = {styles.titleInput} returnKeyType = {"next"} autoFocus = {true} placeholder = "Title" onSubmitEditing={this.handleTitleInputSubmit} /> DescriptionInput's focus prop is set to our focusDescriptionInput state variable. So, when focusDescriptionInput changes (in step 3), DescriptionInput will re-render with focus={true}. <TextInput style = {styles.descriptionInput} multiline = {true} maxLength = {200} placeholder = "Description" focus={this.state.focusDescriptionInput} />
这是避免使用refs的好方法，因为refs会导致更脆弱的代码:)
编辑:h/t @LaneRettig指出，你需要用一些添加的道具和方法来包装React Native TextInput，以获得对焦点的响应:
// Props:
static propTypes = {
focus: PropTypes.bool,
}
static defaultProps = {
focus: false,
}
// Methods:
focus() {
this._component.focus();
}
componentWillReceiveProps(nextProps) {
const {focus} = nextProps;
focus && this.focus();
}
其他回答
你不需要裁判也可以做到。这种方法是首选的，因为引用会导致脆弱的代码。React文档建议在可能的情况下寻找其他解决方案:
If you have not programmed several apps with React, your first inclination is usually going to be to try to use refs to "make things happen" in your app. If this is the case, take a moment and think more critically about where state should be owned in the component hierarchy. Often, it becomes clear that the proper place to "own" that state is at a higher level in the hierarchy. Placing the state there often eliminates any desire to use refs to "make things happen" – instead, the data flow will usually accomplish your goal.
相反，我们将使用一个状态变量来聚焦第二个输入字段。
Add a state variable that we'll pass as a prop to the DescriptionInput: initialState() { return { focusDescriptionInput: false, }; } Define a handler method that will set this state variable to true: handleTitleInputSubmit() { this.setState(focusDescriptionInput: true); } Upon submitting / hitting enter / next on the TitleInput, we'll call handleTitleInputSubmit. This will set focusDescriptionInput to true. <TextInput style = {styles.titleInput} returnKeyType = {"next"} autoFocus = {true} placeholder = "Title" onSubmitEditing={this.handleTitleInputSubmit} /> DescriptionInput's focus prop is set to our focusDescriptionInput state variable. So, when focusDescriptionInput changes (in step 3), DescriptionInput will re-render with focus={true}. <TextInput style = {styles.descriptionInput} multiline = {true} maxLength = {200} placeholder = "Description" focus={this.state.focusDescriptionInput} />
这是避免使用refs的好方法，因为refs会导致更脆弱的代码:)
编辑:h/t @LaneRettig指出，你需要用一些添加的道具和方法来包装React Native TextInput，以获得对焦点的响应:
// Props:
static propTypes = {
focus: PropTypes.bool,
}
static defaultProps = {
focus: false,
}
// Methods:
focus() {
this._component.focus();
}
componentWillReceiveProps(nextProps) {
const {focus} = nextProps;
focus && this.focus();
}
如果您恰好像我一样使用tcomb-form-native，您也可以这样做。这里有一个技巧:不是直接设置TextInput的道具，而是通过选项来实现。您可以将表单的字段引用为:
this.refs.form.getComponent('password').refs.input.focus()
所以最终的产品看起来是这样的:
var t = require('tcomb-form-native');
var Form = t.form.Form;
var MyForm = t.struct({
field1: t.String,
field2: t.String,
});
var MyComponent = React.createClass({
_getFormOptions () {
return {
fields: {
field1: {
returnKeyType: 'next',
onSubmitEditing: () => {this.refs.form.getComponent('field2').refs.input.focus()},
},
},
};
},
render () {
var formOptions = this._getFormOptions();
return (
<View style={styles.container}>
<Form ref="form" type={MyForm} options={formOptions}/>
</View>
);
},
});
(感谢remcoanker在这里发布的想法:https://github.com/gcanti/tcomb-form-native/issues/96)
import React, { useState, useEffect, useRef, } from 'react';
const OTP = (props) => {
const OTP = [];
const ref_input = [];
ref_input[0] = useRef();
ref_input[1] = useRef();
ref_input[2] = useRef();
ref_input[3] = useRef();
const focusNext = (text, index) => {
if (index < ref_input.length - 1 && text) {
ref_input[index + 1].current.focus();
}
if (index == ref_input.length - 1) {
ref_input[index].current.blur();
}
OTP[index] = text;
}
const focusPrev = (key, index) => {
if (key === "Backspace" && index !== 0) {
ref_input[index - 1].current.focus();
}
}
return (
<SafeAreaView>
<View>
<ScrollView contentInsetAdjustmentBehavior="automatic" showsVerticalScrollIndicator={false}>
<View style={loginScreenStyle.titleWrap}>
<Title style={loginScreenStyle.titleHeading}>Verify OTP</Title>
<Subheading style={loginScreenStyle.subTitle}>Enter the 4 digit code sent to your mobile number</Subheading>
</View>
<View style={loginScreenStyle.inputContainer}>
<TextInput
mode="flat"
selectionColor={Colors.primaryColor}
underlineColorAndroid="transparent"
textAlign='center'
maxLength={1}
keyboardType='numeric'
style={formScreenStyle.otpInputStyle}
autoFocus={true}
returnKeyType="next"
ref={ref_input[0]}
onChangeText={text => focusNext(text, 0)}
onKeyPress={e => focusPrev(e.nativeEvent.key, 0)}
/>
<TextInput
mode="flat"
selectionColor={Colors.primaryColor}
underlineColorAndroid="transparent"
textAlign='center'
maxLength={1}
keyboardType='numeric'
style={formScreenStyle.otpInputStyle}
ref={ref_input[1]}
onChangeText={text => focusNext(text, 1)}
onKeyPress={e => focusPrev(e.nativeEvent.key, 1)}
/>
<TextInput
mode="flat"
selectionColor={Colors.primaryColor}
underlineColorAndroid="transparent"
textAlign='center'
maxLength={1}
keyboardType='numeric'
style={formScreenStyle.otpInputStyle}
ref={ref_input[2]}
onChangeText={text => focusNext(text, 2)}
onKeyPress={e => focusPrev(e.nativeEvent.key, 2)}
/>
<TextInput
mode="flat"
selectionColor={Colors.primaryColor}
underlineColorAndroid="transparent"
textAlign='center'
maxLength={1}
keyboardType='numeric'
style={formScreenStyle.otpInputStyle}
ref={ref_input[3]}
onChangeText={text => focusNext(text, 3)}
onKeyPress={e => focusPrev(e.nativeEvent.key, 3)}
/>
</View>
</ScrollView>
</View>
</SafeAreaView >
)
}
export default OTP;
我想分享我的解决方案使用功能组件…“这个”不需要!
React 16.12.0和React Native 0.61.5
这是我的组件的一个例子:
import React, { useRef } from 'react'
...
const MyFormComponent = () => {
const ref_input2 = useRef();
const ref_input3 = useRef();
return (
<>
<TextInput
placeholder="Input1"
autoFocus={true}
returnKeyType="next"
onSubmitEditing={() => ref_input2.current.focus()}
/>
<TextInput
placeholder="Input2"
returnKeyType="next"
onSubmitEditing={() => ref_input3.current.focus()}
ref={ref_input2}
/>
<TextInput
placeholder="Input3"
ref={ref_input3}
/>
</>
)
}
下面是如何为reactjs的电话代码输入实现这一点
import React, { useState, useRef } from 'react';
function Header(props) {
const [state , setState] = useState({
phone_number:"",
code_one:'',
code_two:'',
code_three:'',
code_four:'',
submitted:false,
})
const codeOneInput = useRef(null);
const codeTwoInput = useRef(null);
const codeThreeInput = useRef(null);
const codeFourInput = useRef(null);
const handleCodeChange = (e) => {
const {id , value} = e.target
if(value.length < 2){
setState(prevState => ({
...prevState,
[id] : value
}))
if(id=='code_one' && value.length >0){
codeTwoInput.current.focus();
}
if(id=='code_two' && value.length >0){
codeThreeInput.current.focus();
}
if(id=='code_three' && value.length >0){
codeFourInput.current.focus();
}
}
}
const sendCodeToServer = () => {
setState(prevState => ({
...prevState,
submitted : true,
}))
let codeEnteredByUser = state.code_one + state.code_two + state.code_three + state.code_four
axios.post(API_BASE_URL, {code:codeEnteredByUser})
.then(function (response) {
console.log(response)
})
}
return(
<>
<div className="are">
<div className="POP-INN-INPUT">
<input type="text" id="code_one" ref={codeOneInput} value={state.code_one} onChange={handleCodeChange} autoFocus/>
<input type="text" id="code_two" ref={codeTwoInput} value={state.code_two} onChange={handleCodeChange}/>
<input type="text" id="code_three" ref={codeThreeInput} value={state.code_three} onChange={handleCodeChange}/>
<input type="text" id="code_four" ref={codeFourInput} value={state.code_four} onChange={handleCodeChange}/>
</div>
<button disabled={state.submitted} onClick={sendCodeToServer}>
</div>
</>
)
}
export default
