找到地理位置后使用回調

Question

我正在編寫一個程序來記錄用戶位置的網絡服務。 該程序使用地理位置來查找用戶，並且一旦檢索到位置，便會繼續記錄該位置。 因為地理位置使用回調函數來獲取位置，所以程序只有在找到位置后才能繼續。 問題是由於需要其他變量，我無法在地理定位功能內繼續執行該程序。 因此，我所做的是geoolcaion函數使用以下函數在網頁上顯示了位置

function geoFindMe(){
  navigator.geolocation.getCurrentPosition(success, error, geo_options);
function success(position) {
var latitude = position.coords.latitude;
 var longitude = position.coords.longitude;
 var altitude = position.coords.altitude;
 var accuracy = position.coords.accuracy;
 var time = getTime();
 //post the everything somewhere and then the callback function will fetch the info 
 //may use var time = position.timestamp;
 $("#result").append(time + " " + latitude + " " + longitude); 
}

function error(error) {
 alert("Unable to retrieve your location due to "+error.code + " : " + error.message);
 }//there was a semicolon here

var geo_options = {
 enableHighAccuracy: true,
 maximumAge : 30000,
 timeout : 27000
 };
}

以下代碼調用此函數

 geoFindMe(function successful(){
        //first call geoFindMe function then call successful as a callback
        //the function will retrieve the information that was displayed by the geoFindMe on the webpage
            $("#result").hide();
            var currentLocation = document.getElementById('result');
            document.getElementById('result').innerHTML = "";
            var moved = hasMoved(previousLocation, currentLocation);
            var time = isItTime(moved, lastBuffer, 15);
            if(time){//its time to put the location in the buffer
                currentLocation = currentLocation + "#";// this way we will be able to differentiate between different locations
                charBuffer.wrap(currentLocation);
            }
            dump(stringArray, lastDump, true);
        });

我想做的是一旦找到地理位置，然后調用成功的函數，我試圖做一個回調函數。 問題是由於某種原因，它跳過了大多數成功的回調函數，並繼續執行dump（...）行； 有什么建議么？ 也許我沒有正確編寫成功的函數？ 非常感謝

Answer 1

您所要做的就是在geoFindMe函數中添加一個參數以接受回調。 然后在成功函數中調用它

function geoFindMe(callback){
  navigator.geolocation.getCurrentPosition(success, error, geo_options);
  function success(position) {
     callback&&callback(); // Check if callback exists and then call it.
     var latitude = position.coords.latitude;
     var longitude = position.coords.longitude;
     var altitude = position.coords.altitude;
     var accuracy = position.coords.accuracy;
     var time = getTime();
     //post the everything somewhere and then the callback function will fetch the info 
     //may use var time = position.timestamp;
     $("#result").append(time + " " + latitude + " " + longitude); 
  }  
  function error(error) {
     alert("Unable to retrieve your location due to "+error.code + " : " + error.message);
  }//there was a semicolon here
  var geo_options = {
     enableHighAccuracy: true,
     maximumAge : 30000,
     timeout : 27000
  };
}