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
如果你的TextInput在另一个组件中，要让这个被接受的解决方案工作，你需要从ref“弹出”到父容器的引用。
// MyComponent
render() {
<View>
<TextInput ref={(r) => this.props.onRef(r)} { ...this.props }/>
</View>
}
// MyView
render() {
<MyComponent onSubmitEditing={(evt) => this.myField2.focus()}/>
<MyComponent onRef={(r) => this.myField2 = r}/>
}
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();
}
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;
结合@Eli Johnson的功能组件解决方案和@Rodrigo Tessarollo的CustomTextInput解决方案:
import React, { useRef } from 'react';
import { CustomTextInput } from 'path/to/CustomTextInput';
...
export const MyFormComponent = () => {
const ref_to_input2 = useRef();
return (
<>
<CustomTextInput
placeholder="Input 1"
autoFocus={true}
returnKeyType="next"
onSubmitEditing={() => ref_to_input2.current.focus()}
/>
<CustomTextInput
placeholder="Input 2"
returnKeyType="done"
refInner={ref_to_input2}
onSubmitEditing={/* Do something! */}
/>
</>
)
}
在你的CustomTextInput组件中:
import { TextInput } from "react-native";
export const CustomTextInput = (props) => {
<TextInput
ref={props.refInner}
{...props}
/>
}
RN没有某种类型的Tabindex系统，这很令人恼火。
一个功能性组件，对于我的用例，我有一个字符串id数组用于输入，我遍历并显示每个文本输入。下面的代码将自动跳过所有这些，阻止键盘在字段之间消失/重新出现，并在结束时解散它，还在键盘上显示适当的“动作”按钮。
Typescript, Native Base。
const stringFieldIDs = [ 'q1', 'q2', 'q3' ]; export default () => { const stringFieldRefs = stringFieldIDs.map(() => useRef < any > ()); const basicStringField = (id: string, ind: number) => { const posInd = stringFieldIDs.indexOf(id); const isLast = posInd === stringFieldIDs.length - 1; return ( < Input blurOnSubmit = { isLast } ref = { stringFieldRefs[posInd] } returnKeyType = { isLast ? 'done' : 'next' } onSubmitEditing = { isLast ? undefined : () => stringFieldRefs[posInd + 1].current._root.focus() } /> ); }; return stringFieldIDs.map(basicStringField); };
使用回调引用而不是遗留的字符串引用:
<TextInput
style = {styles.titleInput}
returnKeyType = {"next"}
autoFocus = {true}
placeholder = "Title"
onSubmitEditing={() => {this.nextInput.focus()}}
/>
<TextInput
style = {styles.descriptionInput}
multiline = {true}
maxLength = {200}
placeholder = "Description"
ref={nextInput => this.nextInput = nextInput}
/>
