angular - 知道这是空的

Question

我收到了一些奇怪的错误“这是空的”。我不知道问题是什么。这是我的演示 Stackblitz.com和示例代码作为您的引用。

组件

ngOnInit() {
    this.getCurrentLocation();
  }

  getCurrentLocation() {
   navigator.geolocation.getCurrentPosition(position =>{
        this.lat = position.coords.latitude;
        this.lng = position.coords.longitude;
        this.weatherInfo(this.lat, this.lng)
},function(){
       this.origin = { lat: '3.140853', lng: '2.693207'};
       console.log(this.origin)
       this.weatherInfo(this.origin.lat, this.origin.lng)
})



  }
  weatherInfo(lat, lng){
    console.log(lat, lng);
  }

Answer 1

由于所需的范围，您需要使用箭头函数(() => { 而不是 function() {):

getCurrentLocation() {
   navigator.geolocation.getCurrentPosition(position =>{
        this.lat = position.coords.latitude;
        this.lng = position.coords.longitude;
        this.weatherInfo(this.lat, this.lng)
}, () => { // Here
       this.origin = { lat: '3.140853', lng: '2.693207'};
       console.log(this.origin)
       this.weatherInfo(this.origin.lat, this.origin.lng)
})

也许值得一读:Understanding "this" in javascript with arrow functions或 Arrow functions and the ‘this’ keyword