我試圖使用react來創建元素的列表,並單擊單個元素時更新此列表的父級的狀態。更新React Grandparent狀態從onClick在Grandchild
整體容器是App.jsx(祖父母)
class App extends Component {
constructor(props) {
super(props);
this.state = {
selectedClass: null,
query: "cs 2110"
}
this.handleSelectClass.bind(this);
}
handleSelectClass(classId) {
console.log(classId);
//get the id of the course and get full course details
Meteor.call('getCourseById', classId, function(error, result) {
if (!error) {
console.log(this.state);
this.setState({selectedClass: result, query: ""}, function() {
console.log(this.state.selectedClass);
console.log(this.state.query);
});
} else {
console.log(error)
}
});
}
//check if a class is selected, and show a coursecard only when one is.
renderCourseCard() {
var toShow = <div />; //empty div
if (this.state.selectedClass != null) {
toShow = <CourseCard course={this.state.selectedClass}/>;
}
return toShow;
}
render() {
return (
<div className="container">
<header>
<h1>Todo List</h1>
</header>
<div className='row'>
<input />
<Results query={this.state.query} clickFunc={this.handleSelectClass}/>
</div>
<div className='row'>
<div className="col-md-6">
{this.renderCourseCard()}
</div>
<div className="col-md-6 panel-container fix-contain">
<Form courseId="jglf" />
</div>
</div>
</div>
);
}
}
的父容器是Results.jsx
export class Results extends Component {
constructor(props) {
super(props);
}
renderCourses() {
if (this.props.query != "") {
return this.props.allCourses.map((course) => (
//create a new class "button" that will set the selected class to this class when it is clicked.
<Course key={course._id} info={course} handler={this.props.clickFunc}/>
));
} else {
return <div />;
}
}
render() {
return (
<ul>
{this.renderCourses()}
</ul>
);
}
}
與課程列表項是孫子部件
export default class Course extends Component {
render() {
var classId = this.props.info._id;
return (
<li id={classId} onClick={() => this.props.handler(classId)}>{this.props.info.classFull}</li>
);
}
}
我按照這裏的建議Reactjs - How to pass values from child component to grand-parent component?傳遞迴調函數n,但回調仍然不能識別祖父母的狀態。 console.log(this.state)在App.jsx中返回undefined,即使classId是正確的,並且錯誤顯示爲「Exception in delivery result invocation'getCourseById':TypeError:this.setState不是函數」
這是綁定的問題嗎?我已經嘗試過沒有課程作爲自己的組件,並有相同的問題。
我試過這些改變,但我仍然在日誌中得到一個未定義的this.state(雖然沒有錯誤,流星調試打印「無信息」)。我使用的是最新的Meteor版本,所以我相信它正在運行es6 - 我看到安裝了es5-shim和[email protected]軟件包。 –
剛剛看到你綁定你的函數到組件不正確,它是'this.handleSelectClass = this.handleSelectClass.bind(this);' – Win
啊我錯過了 - 非常感謝你,修復它! –