TypeError: this is not a function at IntroJs._introExitCallback

Question

我正在尝试将 div 传递给 intro.onexit() 上的 showOff，但出现此错误。

TypeError: this.hideStep is not a function
    at IntroJs._introExitCallback (http://localhost:8100/build/main.js:511:18)
    at IntroJs._exitIntro (http://localhost:8100/build/vendor.js:120298:31)
    at HTMLDivElement.overlayLayer.onclick [as __zone_symbol__ON_PROPERTYclick] (http://localhost:8100/build/vendor.js:121508:20)
    at HTMLDivElement.H (http://localhost:8100/build/polyfills.js:3:23950)
    at t.invokeTask (http://localhost:8100/build/polyfills.js:3:15660)
    at Object.onInvokeTask (http://localhost:8100/build/vendor.js:5125:33)
    at t.invokeTask (http://localhost:8100/build/polyfills.js:3:15581)
    at r.runTask (http://localhost:8100/build/polyfills.js:3:10834)
    at e.invokeTask [as invoke] (http://localhost:8100/build/polyfills.js:3:16794)
    at p (http://localhost:8100/build/polyfills.js:2:27648)

我在试图通过 menuCtrl.close() 时也遇到了这个错误。menuCtrl.close() 我必须将它声明到他的函数 intro() 中才能让它工作。我在想，那是因为我正在调用一个组件的函数，所以我实际上必须创建一个组件来将 false 传递给 ?

我现在有点迷茫，我正在学习，也许我的定义有误。

这是我的代码

public step1 = true;

 hideStep(){
    this.step1 = false; 
  }

intro() {
    let intro = introJs.introJs();
    let menuCtrl = this.menuCtrl;

    intro.setOptions({
    steps: [
      {
        intro: "Hello!! we want to give you some recommendations"
      },
      {
        element: '#step1',
        intro: "You can see the profile settings, just tapping in your profile picture",
        position: 'bottom'

      },
      {
        element: '#step2',
        intro: "You can see the profile settings, just tapping in your profile picture",
        position: 'bottom'  
      }
    ]
    });

    intro.start();
    intro.onexit(function() {
      menuCtrl.close();
      this.hideStep();
    });
  }

  ngAfterViewInit(): void {
    this.intro();
  }

Answer 1

尝试使用粗箭头函数代替方法函数，这是this关键字问题：

intro.onexit(() => {
    menuCtrl.close();
    this.hideStep();
});

方法函数的this关键字指的是它所在函数的所有者

TypeError: this is not a function at IntroJs._introExitCallback

TypeError: this is not a function at IntroJs._introExitCallback

typescript

intro.js

ionic3

angular