如何从我使用的result（）回调函数中捕获返回值？ [英] How can I catch the return value from the result() callback function that I'm using?

问题描述

 < script type =text / javascript> 
 var geo = new GClientGeocoder（）; 
 
 function showAddress（）{
 var search = document.getElementById（search）。value; 
 // getLocations没有ret，所以wtf！ 
 geo.getLocations（search，function（result）{（result.Status.code == 200）？alert（result.Placemark [0] .Point.coordinates）：alert（result.Status.code）;} ）; 
}< / script> 
  

我需要回调的ret值，因为getLocations（）不返回任何值。如何做到这一点？

解决方案

你不能。您必须以这样的方式编写代码，即需要 result 值的代码在回调中执行。

示例（

）

function drawPlacemarks（marks）{
//用结果处理奇怪的东西
alert（marks [0] .Point.coordinates）;
}

function getAddress（callback）{
var search = document.getElementById（search）。value;
geo.getLocations（search，function（result）{
if（result.Status.code == 200）{
//将结果传递给回调
callback .Placemark）;
}
}）;
}

getAddress（drawPlacemarks）;

<script type="text/javascript">
  var geo = new GClientGeocoder();

  function showAddress() {
    var search = document.getElementById("search").value;
    // getLocations has not ret, so wtf!
    geo.getLocations(search, function (result) { (result.Status.code == 200) ? alert(result.Placemark[0].Point.coordinates) : alert(result.Status.code); });
  }</script>

I need the ret value of the callback as getLocations() returns no values. How can I do this?

解决方案

You can't. You have to write your code in such a way that the code that needs the result value is executed in the callback.

Example (I just named the function in a way which seems logical to me):

function drawPlacemarks(marks) {
   // do fancy stuff with the results
   alert(marks[0].Point.coordinates);
}

function getAddress(callback) {
    var search = document.getElementById("search").value;
    geo.getLocations(search, function (result) { 
        if(result.Status.code == 200) {
           // pass the result to the callback
           callback(result.Placemark);
        }
    });
}

getAddress(drawPlacemarks);

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