如何自动将下一个TextInput聚焦在react-native上 [英] How to autofocus next TextInput on react-native

问题描述

我正在尝试创建一个受密码保护的屏幕.屏幕将使用4个数字输入作为密码.

I'm trying to create a passcode protected screen. The screen will uses 4 numeric input as the passcode.

我这样做的方法是创建一个TextInput组件，并在主屏幕中将其调用4次.

The way I'm doing this is create a TextInput Component and call it 4 times in my main screen.

我遇到的问题是，当我键入前一个TextInput的值时，TextInputs将不会关注下一个.

The problem I'm having is the TextInputs will not focus on the next one as I type the value of the previous TextInput.

我为所有PasscodeTextInput组件使用了refs(已经被告知这是一种旧方法，但是我不知道其他任何方法)

I'm using refs for all PasscodeTextInput component (I've been informed that it is a legacy method but I do not know any other way, alas).

尝试了这种方法(无需创建自己的组件)，也没有运气. 方法

Tried this method(without creating my own component), no luck too. METHOD

index.ios.js

import React, { Component } from 'react';
import { AppRegistry, TextInput, View, Text } from 'react-native';
import { PasscodeTextInput } from './common';

export default class ProgressBar extends Component {
  render() {
    const { centerEverything, container, passcodeContainer,  textInputStyle} = styles;
    return (
      <View style={[centerEverything, container]}>
        <View style={[passcodeContainer]}>
          <PasscodeTextInput
            autoFocus={true}
            ref="passcode1"
            onSubmitEditing={(event) => { this.refs.passcode2.focus() }} />
          <PasscodeTextInput
            ref="passcode2"
            onSubmitEditing={(event) => { this.refs.passcode3.focus() }} />
          <PasscodeTextInput
            ref="passcode3"
            onSubmitEditing={(event) => { this.refs.passcode4.focus() }}/>
          <PasscodeTextInput
            ref="passcode4" />
        </View>
      </View>
    );
  }
}

const styles = {
  centerEverything: {
    justifyContent: 'center',
    alignItems: 'center',
  },
  container: {
    flex: 1,
    backgroundColor: '#E7DDD3',
  },
  passcodeContainer: {
    flexDirection: 'row',
  },
}

AppRegistry.registerComponent('ProgressBar', () => ProgressBar);

PasscodeTextInput.js

import React from 'react';
import {
  View,
  Text,
  TextInput,
  Dimensions
} from 'react-native';

const deviceWidth = require('Dimensions').get('window').width;
const deviceHeight = require('Dimensions').get('window').height;

const PasscodeTextInput = ({ ref, autoFocus, onSubmitEditing, onChangeText, value}) => {

  const { inputStyle, underlineStyle } = styles;

  return(
    <View>
      <TextInput
        ref={ref}
        autoFocus={autoFocus}
        onSubmitEditing={onSubmitEditing}
        style={[inputStyle]}
        maxLength={1}
        keyboardType="numeric"
        placeholderTextColor="#212121"
        secureTextEntry={true}
        onChangeText={onChangeText}
        value={value}
      />
      <View style={underlineStyle} />
    </View>
  );
}

const styles = {
  inputStyle: {
    height: 80,
    width: 60,
    fontSize: 50,
    color: '#212121',
    fontSize: 40,
    padding: 18,
    margin: 10,
    marginBottom: 0
  },
  underlineStyle: {
    width: 60,
    height: 4,
    backgroundColor: '#202020',
    marginLeft: 10
  }
}

export { PasscodeTextInput };

更新1

index.ios.js

import React, { Component } from 'react';
import { AppRegistry, TextInput, View, Text } from 'react-native';
import { PasscodeTextInput } from './common';

export default class ProgressBar extends Component {

  constructor() {
    super()
    this.state = {
      autoFocus1: true,
      autoFocus2: false,
      autoFocus3: false,
      autoFocus4: false,
    }
  }

  onTextChanged(t) { //callback for immediate state change
    if (t == 2) { this.setState({ autoFocus1: false, autoFocus2: true }, () => { console.log(this.state) }) }
    if (t == 3) { this.setState({ autoFocus2: false, autoFocus3: true }, () => { console.log(this.state) }) }
    if (t == 4) { this.setState({ autoFocus3: false, autoFocus4: true }, () => { console.log(this.state) }) }
  }

  render() {
    const { centerEverything, container, passcodeContainer, testShit, textInputStyle } = styles;
    return (
      <View style={[centerEverything, container]}>
        <View style={[passcodeContainer]}>
          <PasscodeTextInput
            autoFocus={this.state.autoFocus1}
            onChangeText={() => this.onTextChanged(2)} />
          <PasscodeTextInput
            autoFocus={this.state.autoFocus2}
            onChangeText={() => this.onTextChanged(3)} />
          <PasscodeTextInput
            autoFocus={this.state.autoFocus3}
            onChangeText={() => this.onTextChanged(4)} />
          <PasscodeTextInput
            autoFocus={this.state.autoFocus4} />
        </View>
      </View>
    );
  }
}

const styles = {
  centerEverything: {
    justifyContent: 'center',
    alignItems: 'center',
  },
  container: {
    flex: 1,
    backgroundColor: '#E7DDD3',
  },
  passcodeContainer: {
    flexDirection: 'row',
  },
}

AppRegistry.registerComponent('ProgressBar', () => ProgressBar);

推荐答案

您不能使用该方式将ref转发到<TextInput>，因为ref是

You cannot forward the ref to <TextInput> using that way because ref is one of the special props. Thus, calling this.refs.passcode2 will return you <PasscodeTextInput> instead.

尝试更改为以下内容，以从<TextInput>获取ref.

Try change to the following to get the ref from <TextInput>.

PasscodeTextInput.js

const PasscodeTextInput = ({ inputRef, ... }) => {

  ...

  return (
    <View>
      <TextInput
        ref={(r) => { inputRef && inputRef(r) }}
        ...
      />
    </View>
    ...
  );
}

然后，将inputRef从<PasscodeTextInput>分配给变量，然后使用focus()切换焦点(从RN 0.41.2开始不推荐使用).

Then, assign the inputRef from <PasscodeTextInput> to a variable and use focus() to switch focus (it is not deprecated as of RN 0.41.2).

index.ios.js

return (
  <PasscodeTextInput
    autoFocus={true}
    onChangeText={(event) => { event && this.passcode2.focus() }} />

  <PasscodeTextInput
    inputRef={(r) => { this.passcode2 = r }}
    onChangeText={(event) => { event && this.passcode3.focus() }} />

  <PasscodeTextInput
    inputRef={(r) => { this.passcode3 = r }}
    onChangeText={(event) => { event && this.passcode4.focus() }} />

  <PasscodeTextInput
    inputRef={(r) => { this.passcode4 = r }} />
);

P.S:event && this.passcode2.focus()防止在尝试清除旧密码并输入新密码时切换焦点.

P.S: event && this.passcode2.focus() prevents focus is switched when trying to clear the old passcode and enter a new one.

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