我是反应js的初学者,想知道为什么splice()方法对我来说不能正常工作。我的方法在这里:
removePara = index => {
let array = [...this.state.paras];
for (let x = 0; x < this.state.count; x++) {
try {
if (array[x].props.id == index) {
array.splice(x, 1);
}
} catch (e) {}
}
this.setState({ paras: array });
};
因此,我传递了一个索引,如果元素的ID与索引匹配,则该元素将被删除。我使用了try-catch,因为并非所有索引都在那里(它们可能已经通过同一函数删除了)。这是三个元素的图像:
不是删除第二个,而是删除最后一个。我该如何解决?我知道我按钮的onclick效果很好。完整代码如下:
//index.js
const rootElement = document.getElementById("root");
class App extends React.Component {
state = {
paras: [],
count: 0
};
addPara = () => {
this.setState({
paras: [
...this.state.paras,
<Paragraph id={this.state.count++} remove={this.removePara} />
]
});
};
removePara = index => {
let array = this.state.paras.filter(e => e.props.id !== index);
this.setState({ paras: array });
};
render() {
return (
<div>
{this.state.paras}
<div className="btn btn-warning" id="add" onClick={this.addPara}>
Add Paragraph
</div>
<div name="count">{this.state.count}</div>
</div>
);
}
}
ReactDOM.render(<App />, rootElement);
//Paragraph.js
class Paragraph extends React.Component {
render() {
let style = {
height: "150px",
marginBottom: "10px"
};
return (
<div className="paragraph" id={this.props.id}>
<div className="row">
<div className="col-sm-11">
<textarea
className="form-control"
name={"paragraph" + this.props.id}
placeholder="Put Paragraph Here"
style={style}
required
></textarea>
</div>
<div className="col-sm-1">
<div
className="btn btn-danger del-rotate"
onClick={() => this.props.remove(this.props.id)}
>
×
</div>
</div>
</div>
</div>
);
}
}
<!--index.html-->
<html>
<head>
<script type="application/javascript" src="../reactjs/react.js"></script>
<script type="application/javascript" src="../reactjs/react-dom.js"></script>
<script type="application/javascript" src="../reactjs/babel.js"></script>
<link rel="stylesheet" type="text/css" href="../css/styles.css">
<script src="../bootstrap/js/bootstrap.min.js"></script>
<link rel="stylesheet" type="text/css" href="../bootstrap/css/bootstrap.min.css">
<script type="text/babel" src="Components/Paragraph.js"></script>
<script type="text/babel" src="index.js"></script>
</head>
<body id="body">
<div class="container-fluid">
<br>
<br>
<div class="row">
<div class="col-sm-1"></div>
<div class="col-sm-10">
<div align="center">
<h1>Write Article</h1>
</div>
<br>
<form action="submit-article.php" method="POST">
<input class="form-control input-sm" type="text" placeholder="Enter Title" name="title"
style="width: 35%" autofocus required></input>
<br>
<div id="root"></div>
<br>
<input class="btn btn-success float-right" type="submit" value="Done">
</form>
</div>
</div>
</div>
</body>
</html>
但是与id匹配的元素将被删除,就像在元素中那样,它不存在,但是被删除的元素的输入只会进入另一个元素。就像上面图片中的例子
您传递的index
可能不正确,
Array.filter
将更适合此类任务:
removePara = index => {
let array = this.state.paras.filter(e => e.props.id !== index);
this.setState({ paras: array });
};