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)

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>

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}/>
}

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}
      />
    </>
  )
}

在你的组件中:

constructor(props) {
        super(props);
        this.focusNextField = this
            .focusNextField
            .bind(this);
        // to store our input refs
        this.inputs = {};
    }
    focusNextField(id) {
        console.log("focus next input: " + id);
        this
            .inputs[id]
            ._root
            .focus();
    }

注意:我使用了._root,因为它是NativeBase' library ' Input中的TextInput的引用

在文本输入中,像这样

<TextInput
         onSubmitEditing={() => {
                          this.focusNextField('two');
                          }}
         returnKeyType="next"
         blurOnSubmit={false}/>


<TextInput      
         ref={input => {
              this.inputs['two'] = input;
                        }}/>