jQuery this 关键字与 typescript this 冲突

Question

我是打字新手 当我使用 jQuery 时，

export class IDE{
    init():any{
    $("select").on("change",function(){
        this.run();//cannot working because we in jQuery context.
    })

    }

    run():any{
    }
}

这个关键字被 jQuery 'this' 关键字覆盖了，谁能给我一些想法？

Answer 1

您可以通过 3 种方式解决上下文问题，给您:

1) Use fat arrow :

$("select").on("change",() => {
    this.run();
})

---

2) Use bind :

$("select").on("change",function(){
    this.run();
}.bind(this)); // <----- HERE

---

3) Pass the reference of this :

export class IDE{

    init():any {
        let self = this;
        $("select").on("change",function(){
            self.run();
        })
    }

    run():any{
    }
}

Reason For Not Working Before : every new function defined its own this value (based on how function was called, a new object in the case of a constructor, undefined in strict mode function calls, the base object if the function is called as an "object method", etc.)