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();
}