Bing地圖AJAX API V7地理位置回電

Question

我的用戶Bing地圖阿賈克斯V7 API從範例中得到用戶的位置here

是否有可能要等到執行回調，直到我得到一個經度，緯度爲用戶的位置或錯誤，如果他/她不允許獲得職位？

function test() { 
      //Call GetMap() to get position 
      GetMap(); 
      //Wait until callback is finished 
     //Do something with user's location (result of the callback) 

    } 

    function GetMap() 
    { 

     // Set the map options 
     var mapOptions = {credentials:"Bing Maps Key"}; 


     // Initialize the map 
     var map = new Microsoft.Maps.Map(document.getElementById("mapDiv"), mapOptions); 

     // Initialize the location provider 
     var geoLocationProvider = new Microsoft.Maps.GeoLocationProvider(map); 

     // Get the user's current location 
     geoLocationProvider.getCurrentPosition({successCallback:displayCenter}); 

     //Execute some more code with user's location 
    } 

    function displayCenter(args) 
    { 
     // Display the user location when the geo location request returns 
     alert("The user's location is " + args.center); 
    } 

Answer 1

在JavaScript中，我不認爲你可以明確地停止執行，並且等待回調結束的注意這裏：jQuery: wait for function to complete to continue processing?如果您有依賴於獲得位置回調，爲什麼不結果一些邏輯只需調用該邏輯作爲回調的一部分？你不需要明確地等待它。關於你想要完成的事情，是這樣的，你在找什麼？

var map; 
function test() { 
     //Call GetMap() to get position 
     GetMap(); 
     //Wait until callback is finished 
    //Do something with user's location (result of the callback) 

} 

function GetMap() 
{ 

    // Set the map options 
    var mapOptions = {credentials:"Bing Maps Key"}; 


    // Initialize the map 
    map = new Microsoft.Maps.Map(document.getElementById("mapDiv"), mapOptions); 

    // Initialize the location provider 
    var geoLocationProvider = new Microsoft.Maps.GeoLocationProvider(map); 

    // Get the user's current location 
    geoLocationProvider.getCurrentPosition({successCallback:displayCenter},{errorCallback:onError}); 
} 

function onPositionReady(position) { 
    // Execute some more code with user's location 
    // For Example... 
    // Apply the position to the map 
    var location = new Microsoft.Maps.Location(position.coords.latitude, 
     position.coords.longitude); 
    map.setView({ zoom: 18, center: location }); 

    // Add a pushpin to the map representing the current location 
    var pin = new Microsoft.Maps.Pushpin(location); 
    map.entities.push(pin); 
} 

function onError(err) { 
    switch (err.code) { 
     case 0: 
      alert("Unknown error"); 
      break; 
     case 1: 
      alert("The user said no!"); 
      break; 
     case 2: 
      alert("Location data unavailable"); 
      break; 
     case 3: 
      alert("Location request timed out"); 
      break; 
    } 
} 

更新： 如果你想傳遞參數到您的回調，您可以使用功能的結合來覆蓋你的回調裏面的this關鍵字和參數傳遞這樣：

例如，如果集高達myObject包含你的論點，你可以把它像這樣：

geoLocationProvider.getCurrentPosition({ successCallback: onPositionReady.bind(myObject) }, { errorCallback: onError }); 

然後，您通過訪問myObject的在回調關鍵字：

function onPositionReady(position) { 
    var myProperty = this.yourProperty; // this now refers to myObject 
    // Execute some more code with user's location 
    // For Example... 
    // Apply the position to the map 
    var location = new Microsoft.Maps.Location(position.coords.latitude, 
     position.coords.longitude); 
    map.setView({ zoom: 18, center: location }); 

    // Add a pushpin to the map representing the current location 
    var pin = new Microsoft.Maps.Pushpin(location); 
    map.entities.push(pin); 
}