反应 - 未捕获的类型错误:无法读取未定义的属性“setState" [英] React - uncaught TypeError: Cannot read property 'setState' of undefined
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问题描述
我收到以下错误
<块引用>未捕获的类型错误:无法读取未定义的属性setState"
即使在构造函数中绑定 delta 之后.
class Counter 扩展 React.Component {构造函数(道具){超级(道具);this.state = {数 : 1};this.delta.bind(this);}增量(){this.setState({计数:this.state.count++});}使成为() {返回 (<div><h1>{this.state.count}</h1><button onClick={this.delta}>+</button>
);}}
解决方案
这是由于 this.delta
没有绑定到 this
.
为了在构造函数中绑定set this.delta = this.delta.bind(this)
:
构造函数(道具){超级(道具);this.state = {数 : 1};this.delta = this.delta.bind(this);}
目前,您正在调用 bind.但是 bind 返回一个绑定函数.您需要将函数设置为其绑定值.
I am getting the following error
Uncaught TypeError: Cannot read property 'setState' of undefined
even after binding delta in the constructor.
class Counter extends React.Component {
constructor(props) {
super(props);
this.state = {
count : 1
};
this.delta.bind(this);
}
delta() {
this.setState({
count : this.state.count++
});
}
render() {
return (
<div>
<h1>{this.state.count}</h1>
<button onClick={this.delta}>+</button>
</div>
);
}
}
解决方案
This is due to this.delta
not being bound to this
.
In order to bind set this.delta = this.delta.bind(this)
in the constructor:
constructor(props) {
super(props);
this.state = {
count : 1
};
this.delta = this.delta.bind(this);
}
Currently, you are calling bind. But bind returns a bound function. You need to set the function to its bound value.
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