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
对于RN 0.50.3的我来说，这是可能的:
<TextInput
autoFocus={true}
onSubmitEditing={() => {this.PasswordInputRef._root.focus()}}
/>
<TextInput ref={input => {this.PasswordInputRef = input}} />
你必须看到这个。
其他回答
在React Native的GitHub问题上尝试这个解决方案。
https://github.com/facebook/react-native/pull/2149#issuecomment-129262565
你需要为TextInput组件使用ref道具。 然后你需要创建一个函数，该函数在onSubmitEditing道具上被调用，将焦点移动到第二个TextInput引用上。
var InputScreen = React.createClass({
_focusNextField(nextField) {
this.refs[nextField].focus()
},
render: function() {
return (
<View style={styles.container}>
<TextInput
ref='1'
style={styles.input}
placeholder='Normal'
returnKeyType='next'
blurOnSubmit={false}
onSubmitEditing={() => this._focusNextField('2')}
/>
<TextInput
ref='2'
style={styles.input}
keyboardType='email-address'
placeholder='Email Address'
returnKeyType='next'
blurOnSubmit={false}
onSubmitEditing={() => this._focusNextField('3')}
/>
<TextInput
ref='3'
style={styles.input}
keyboardType='url'
placeholder='URL'
returnKeyType='next'
blurOnSubmit={false}
onSubmitEditing={() => this._focusNextField('4')}
/>
<TextInput
ref='4'
style={styles.input}
keyboardType='numeric'
placeholder='Numeric'
blurOnSubmit={false}
onSubmitEditing={() => this._focusNextField('5')}
/>
<TextInput
ref='5'
style={styles.input}
keyboardType='numbers-and-punctuation'
placeholder='Numbers & Punctuation'
returnKeyType='done'
/>
</View>
);
}
});
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)
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();
}
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); };
此处为具有:focus属性的输入组件的试剂溶液。
只要这个道具设置为true，字段就会被聚焦;如果这个道具设置为false，字段就不会有焦点。
不幸的是，这个组件需要定义一个:ref，我找不到其他方法来调用.focus()。我很高兴听到建议。
(defn focusable-input [init-attrs]
(r/create-class
{:display-name "focusable-input"
:component-will-receive-props
(fn [this new-argv]
(let [ref-c (aget this "refs" (:ref init-attrs))
focus (:focus (ru/extract-props new-argv))
is-focused (.isFocused ref-c)]
(if focus
(when-not is-focused (.focus ref-c))
(when is-focused (.blur ref-c)))))
:reagent-render
(fn [attrs]
(let [init-focus (:focus init-attrs)
auto-focus (or (:auto-focus attrs) init-focus)
attrs (assoc attrs :auto-focus auto-focus)]
[input attrs]))}))
https://gist.github.com/Knotschi/6f97efe89681ac149113ddec4c396cc5
