ReactJS:如何按顺序映射JSON元素并在点击时显示隐藏的div
我试图从JSON中加载项目,并在点击时使用描述切换下拉div。虽然我可以在静态div上按顺序显示元素(例如:loc1 & desc1, loc2 & desc2
),但在第二部分(desc)隐藏时只能在点击loc loc时显示如何正确渲染它。ReactJS:如何按顺序映射JSON元素并在点击时显示隐藏的div
什么是映射结果的最佳方式,因此它不显示为loc1 & loc2, desc1 & desc2
而是loc1 & desc1, loc2 & desc2
?
代码:
var places = { library: {
location: [
{
loc_name: "library1",
"desc": "desc1 : Modern and spacious building"
},
{
loc_name: "library2",
"desc": "desc2 : A cosy small building"
}
]
}
};
function contentClass(isShow) {
if (isShow) {
return "content";
}
return "content invisible";
}
class Toggle extends React.Component {
constructor(props) {
super(props);
this.state = { isShow: false };
this.handleClick = this.handleClick.bind(this);
}
handleClick() {
this.setState(function (prevState) {
return { isShow: !prevState.isShow };
});
}
render() {
const libraries_desc = places.library.location.map((libr) =>
<div>
<p>{libr.desc}</p>
</div>
);
const lib_names = places.library.location.map((libr) =>
<div>
<p>{libr.loc_name}</p>
</div>
);
return (
<div>
<div className='control' onClick={this.handleClick}>
<h4>{lib_names}</h4>
<div className={contentClass(this.state.isShow)}>{libraries_desc}</div>
</div>
</div>
);
}
}
render((
<Toggle />
), document.getElementById('root'));
当前的结果:
library1 library2
desc1 : Modern and spacious building
desc 2 : A cosy small building
所需的结果:
library1 desc1 : Modern and spacious building (hidden but shown when clicked)
library2
desc 2 : A cosy small building (hidden but shown when clicked)
Codesandbox
回答:
我可能会尝试将位置提取到单独的组件中。通过提取它,每个位置负责了解其状态。在你的情况下,这意味着它的可见性(由this.state.isShow
控制)。
这里是你如何能做到这一点:
import React from 'react'; import { render } from 'react-dom';
var places = {
library: {
location: [
{
loc_name: "library1",
"desc": "Modern and spacious building"
},
{
loc_name: "library2",
"desc": "A cosy small building"
}
]
}
};
class Location extends React.Component {
constructor(props) {
super(props);
this.state = { isShow: false };
this.handleClick = this.handleClick.bind(this);
}
handleClick() {
this.setState(function (prevState) {
return { isShow: !prevState.isShow };
});
}
contentClass(isShow) {
if (isShow) {
return "content";
}
return "content invisible";
}
render() {
return (
<div className='control' onClick={this.handleClick}>
<h4>{this.props.desc}</h4>
<div className={this.contentClass(this.state.isShow)}>{this.props.loc_name}</div>
</div>
)
}
}
class Toggle extends React.Component {
constructor(props) {
super(props);
}
render() {
const locations = places.library.location.map(location => {
return <Location {...location} />
})
return (
<div>
{locations}
</div>
);
}
}
render((
<Toggle />
), document.getElementById('root'));
回答:
你Toggle
组件应b像这样。
class Toggle extends React.Component { constructor(props) {
super(props);
this.state = {
isShow: false,
id: -1, // initial value
};
}
handleClick = (id) => {
this.setState({
isShow: !this.state.isShow,
id: id
});
}
render() {
const { location } = places.library;
const { isShow, id } = this.state;
return (
<div className="control">
{location.map((libr, index) => (
<div key={index} onClick={() => { this.handleClick(index) }}>
<p>{libr.loc_name}</p>
{(isShow && (id === index)) && <p>{libr.desc}</p>}
</div>
))}
</div>
);
}
}
所以,当你点击div
元素。点击事件将被触发,称为,它将传递index
作为该函数的参数。这会将isShow设置为false或truth,反之亦然,以及要显示的当前元素将通过this.state.id
进行选择。所以每次isShow
为真,this.state.id
匹配index
数组的元素。您的描述将显示,否则它会隐藏,只要你想。
所以你想要的结果会是这样的。
library1 desc1 : Modern and spacious building (hidden but shown when clicked)
library2
desc 2 : A cosy small building (hidden but shown when clicked)
以上是 ReactJS:如何按顺序映射JSON元素并在点击时显示隐藏的div 的全部内容, 来源链接: utcz.com/qa/267286.html