我正在使用Typescript反应构建一个Web应用程序。我正在尝试制作一个可以扩展点击的手风琴菜单,但它只响应第二次点击。我想这是因为它只在第一次点击后开始收听。
有没有办法让它从一开始就听?我尝试在构造函数中初始化事件侦听器,但它似乎没有工作。
这是我的班级:
class SelectionMenu extends React.Component {
constructor(props: Readonly<{}>){
super(props);
this.listenForAccordion = this.listenForAccordion.bind(this);
}
// opens and closes the accordian menu
public listenForAccordion(): void {
for (i = 0; i < acc.length; i++) {
acc[i].addEventListener("click", function() {
this.classList.toggle("active");
var panel = this.nextElementSibling;
if (panel.style.maxHeight){
panel.style.maxHeight = null;
} else {
panel.style.maxHeight = panel.scrollHeight + "px";
}
});
}
}
public render() {
return (
<div className="App-selectionmenu">
<button className="Accordion" onClick={this.listenForAccordion}>Section 1</button>
<div className="Panel">
<p>Lorem ipsum...</p>
</div>
<button className="Accordion" onClick={this.listenForAccordion}>Section 2</button>
<div className="Panel">
<p>Lorem ipsum...</p>
</div>
<button className="Accordion" onClick={this.listenForAccordion}>Section 3</button>
<div className="Panel">
<p>Lorem ipsum...</p>
</div>
</div>
);
}
}
您可以将手风琴行信息保持在组件状态,并将行设置为active
而不是手动操作DOM,而是在render方法中将该行设置为应用于该行的样式。
例
class SelectionMenu extends React.Component {
state = {
rows: [{ active: false }, { active: false }, { active: false }]
};
onClick = index => {
this.setState(previousState => {
const rows = [...previousState.rows];
rows[index] = { ...rows[index], active: !rows[index].active };
return { rows };
});
};
render() {
return (
<div className="App-selectionmenu">
{this.state.rows.map((row, index) => (
<div key={index}>
<button className="Accordion" onClick={() => this.onClick(index)}>
Section 1
</button>
<div className="Panel">
<p>Lorem ipsum... {row.active && " (Active!)"}</p>
</div>
</div>
))}
</div>
);
}
}
ReactDOM.render(<SelectionMenu />, document.getElementById("root"));
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>
<div id="root"></div>