javascript - 如何将以下内容绑定(bind)到按钮单击事件上的本地 this 上下文变量？

Question

我真的需要这方面的帮助。如何使用按钮单击事件打印纬度和经度，例如:

<button id="geo" onclick="OnGeoClick()"> Get Location </button>

我有以下代码:

var getGeo = {
    showPosition  : 
    function showPosition(position) {
        self = this;
        console.log(self)
        self.lat = position.coords.latitude;
        self.lng = position.coords.longitude;
        console.log(self);
    },


    showError :
    function showError(error) {
        switch(error.code) {
            case error.PERMISSION_DENIED:
                this.err = "User denied the request for Geolocation.";
                break;
            case error.POSITION_UNAVAILABLE:
                this.err = "Location information is unavailable.";
                break;
            case error.TIMEOUT:
                this.err = "The request to get user location timed out.";
                break;
            case error.UNKNOWN_ERROR:
              this.err = "An unknown error occurred.";
              break;
        }
    },

    getLocation :
    function getLocation() {
            self = this;
            if (navigator.geolocation) {
                navigator.geolocation.getCurrentPosition(self.showPosition, self.showError, {enableHighAccuracy:true});
                console.log(self);
            } else { 
                self.err = "Geolocation is not supported by this browser.";}
    }
};

function OnGeoClick() {...local this context binding?...}

这样窗口不存储纬度和经度，而是一个可以记录(结果)的可访问变量；

Answer 1

您可以使用绑定(bind)方法来保持上下文完整。

navigator.geolocation.getCurrentPosition(self.showPosition.bind(self), self.showError, {enableHighAccuracy:true});

这样调用它

function OnGeoClick() { 
  getGeo.getLocation();
}