我正在尝试从表中编辑值并将其放在文本框中。当我单击编辑按钮时,它显示“无法读取未定义的属性编辑名称”。我使用了胖箭头功能。我还在构造函数中使用了bind,但是它有同样的错误。以下是我的代码。当单击editName按钮时,它给出错误。
class App extends React.Component {
constructor(props) {
super(props);
this.onNameChange = this.onNameChange.bind(this);
this.onSurnameChange = this.onSurnameChange.bind(this);
this.onIdChange = this.onIdChange.bind(this);
this.editName = this.editName.bind(this);
this.state = {
data: "",
name: "",
surname: "",
id: ""
};
}
componentDidMount() {
axios.get("http://localhost:4000/employees").then((response, err) => {
if (err) {
console.log("err");
}
this.setState(prevstate => ({
data: response.data
}));
});
}
handleSumbit(e) {
axios
.post("http://localhost:4000/employees", {
name: this.state.name,
surname: this.state.surname,
id: this.state.id
})
.then((response, err) => {
if (err) {
console.log("Error While Posting Data", err);
}
console.log("RESPONSE FROM POST", response);
});
}
onNameChange(e) {
this.setState({
name: e.target.value
});
}
onSurnameChange(e) {
this.setState({
surname: e.target.value
});
}
onIdChange(e) {
this.setState({
id: e.target.value
});
}
editName(value) {
this.setState({
name: value
});
}
editSurname(e, value) {
this.setState({
surname: value
});
}
render() {
const { data } = this.state;
return (
<div className="container">
<div>
<label className="">Name</label>
<input
type="text"
name=""
value={this.state.name}
onChange={e => this.onNameChange(e)}
/>
</div>
<div>
<label className="">Surname</label>
<input
type="text"
name=""
value={this.state.surname}
onChange={e => this.onSurnameChange(e)}
/>
</div>
<div>
<label className=""> YOUR ID </label>
<input
type="number"
name=""
value={this.state.id}
onChange={e => this.onIdChange(e)}
/>
</div>
<div>
<button type="button" onClick={e => this.handleSumbit(e)}>
Sumbit
</button>
</div>
<div className="main-container">
{data &&
data.map(function(data, key) {
return (
<React.Fragment>
<div className="child">
{data.name}
<button onClick={e => this.editName("Samar")}>Edit</button>
</div>
<div className="child">
{data.surname}
<button onClick={e => this.editSurname(e, data.surname)}>
Edit
</button>
</div>
</React.Fragment>
);
})}
</div>
</div>
);
}
}
export default App;
最佳答案
我已经注意到(如@DanO所说),在渲染方法中使用内部贴图this
时,undefined
不再是窗口对象,而是function
。解决方案非常简单,可以将其更改为箭头功能(首选),也可以使用Function.prototype.bind
。
data.map((data, key) => (<>...</>))