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

如果你正在使用NativeBase作为UI组件,你可以使用这个示例

<Item floatingLabel>
    <Label>Title</Label>
    <Input
        returnKeyType = {"next"}
        autoFocus = {true}
        onSubmitEditing={(event) => {
            this._inputDesc._root.focus(); 
        }} />
</Item>
<Item floatingLabel>
    <Label>Description</Label>
    <Input
        getRef={(c) => this._inputDesc = c}
        multiline={true} style={{height: 100}} />
        onSubmitEditing={(event) => { this._inputLink._root.focus(); }} />
</Item>

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}
  />
}

从React Native 0.36开始,不再支持在文本输入节点上调用focus()(在其他几个答案中建议)。相反,你可以使用React Native中的TextInputState模块。我创建了以下帮助模块,使这更容易:

// TextInputManager
//
// Provides helper functions for managing the focus state of text
// inputs. This is a hack! You are supposed to be able to call
// "focus()" directly on TextInput nodes, but that doesn't seem
// to be working as of ReactNative 0.36
//
import { findNodeHandle } from 'react-native'
import TextInputState from 'react-native/lib/TextInputState'


export function focusTextInput(node) {
  try {
    TextInputState.focusTextInput(findNodeHandle(node))
  } catch(e) {
    console.log("Couldn't focus text input: ", e.message)
  }
}

然后,您可以在TextInput的任何“ref”上调用focusTextInput函数。例如:

...
<TextInput onSubmit={() => focusTextInput(this.refs.inputB)} />
<TextInput ref="inputB" />
...

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}
/>

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}/>
}