如何将使用“ this”关键字的函数传递给JavaScript类？

Question

I have a class

class MenuItem {
  constructor(title, onPress) {
    this.title = title;
    this.onPress = onPress;
  }
}

When I invoke the constructor using new MenuItem("MyMenuItem", (event) => { console.log(this.title); }); the keyword this is referring to scope that I'm creating the MenuItem in.

Is there a way to use this.title in the function I'm passing to my constructor?

Answer 1

Not with an arrow function. Arrow functions dont have their own context (aka this ) , so you need a regular one:

MenuItem("MyMenuItem", function(event){ 
  console.log(this.title); 
});

Answer 2

这样的事情应该起作用：

this.onPress = onPress.bind(this)