Javascript 地理定位与距离计算

我有一些计划。我想读取手机的当前位置，并计算从数据库加载的一些位置之间的距离。每个部分都能完美分开，但我不能让它配合。当我计算距离时，似乎还没有得到手机的位置（至少我认为是这个问题）

请帮我找到解决办法！我将非常感激

TrackPosition.js：

var op, prev_lat, prev_long, info_string="", current_lat=0, current_long=0, wpid;


function format_time_component(time_component){
    op=document.getElementById("output");

    if(time_component<10)
        time_component="0"+time_component;
    else if(time_component.length<2)
        time_component=time_component+"0";

    return time_component;
}

function geo_success(position){ 
    info_string="";
    var d=new Date(); // Date object, used below for output messahe
    var h=d.getHours();
    var m=d.getMinutes();
    var s=d.getSeconds();

    var current_datetime=format_time_component(h)+":"+format_time_component(m)+":"+format_time_component(s);

    if(prev_lat!=position.coords.latitude || prev_long!=position.coords.longitude){
        prev_lat=position.coords.latitude;
        prev_long=position.coords.longitude;
        current_lat=position.coords.latitude;
        current_long=position.coords.longitude;

        info_string="Current positon: lat="+current_lat+", long="+current_long+
        " (accuracy "+Math.round(position.coords.accuracy, 1) +"m) " + current_datetime + "<br>";

    }


    if(info_string)
        op.innerHTML=info_string;
}


function geo_error(error) {
    switch(error.code)
    {
        case error.TIMEOUT:
            op.innerHTML="Timeout!";
        break;
    };
}

function posInit()
{
    if(!!navigator.geolocation){
        wpid=navigator.geolocation.watchPosition(geo_success, geo_error, {
                                                                            enableHighAccuracy:true, 
                                                                            maximumAge:30000, 
                                                                            timeout:27000});
    } else{
        op.innerHTML="ERROR: Your Browser doesnt support the Geo Location API";
    }
}

window.onload=posInit();

var op，prev_lat，prev_long，info_string=“”，current_lat=0，current_long=0，wpid；
函数格式\u时间\u组件（时间\u组件）{
op=document.getElementById（“输出”）；
if（时间）组件
var s=；
文件写入（距离（当前纬度、当前纬度、s.lat、s.long））；

我想您需要在geolocation回调函数中计算距离，但如何从geolocation回调函数中的数据库中获取某个位置的坐标呢？geolocation函数运行良好。我想PHP脚本也可以运行良好，您可以使用它来填充javascript变量“s”-PHP脚本将始终s在页面呈现之前完成，以便可以将javascript变量写入页面（如上所述）在包含其他javascript文件之前。然后加载页面，geolocation函数关闭并执行它的操作-由于您全局声明变量“s”，回调函数应该可以访问“s”-这意味着回调函数可以将“s”的值传递给距离计算函数，但它没有。Whe我从未将“s”传递给回调函数，因为它被视为未定义。我尝试了几种组合来实现这一点，但没有任何成功。这非常奇怪……我在声明“s”后加载TrackPosition.js。我没有收到任何关于未声明变量的错误，但仍然没有填充值。：/将其指定为其他变量名-可能是y你有冲突吗？当我像你一样尝试使用“s”时，我也得到了一个数字-因此我将其改为“sdata”，似乎一切正常。我看到了从现在开始得到的数字-在geo_成功函数中，你将“s”指定为秒

<?php
class Package{
    public $id;
    public $names;
    public $surname;
    public $street;
    public $city;
    public $country;
    public $long;
    public $lat;

    public function __construct($id, $names, $surname, $street, $city, $country) {
        $this->id = $id;
        $this->names = $names;
        $this->surname = $surname;
        $this->street = str_replace(' ', '+', $street);
        $this->city = $city;
        $this->country = $country;
        $this->getPosition();   
    }

    public function getPosition(){
        $address = $this->street . "+" . $this->city . "+" .$this->country;

        $url = "http://maps.google.com/maps/api/geocode/json?address=" . $address . "&sensor=false&region=UK";
        $response = file_get_contents($url);
        $response = json_decode($response, true);

        $this->lat = $response['results'][0]['geometry']['location']['lat'];
        $this->long = $response['results'][0]['geometry']['location']['lng'];
    }

    public function toJSON(){
        $json = array(
            'id' => $this->id,
            'names' => $this->names,
            'surname' => $this->surname,
            'street' => $this->street,
            'city' => $this->city,
            'country' => $this->country,
            'lat' => $this->lat,
            'longs' => $this->long
        );
        return json_encode($json);
    }
}

$link = mysql_connect("localhost", "root", "");
mysql_select_db("COURIERKIT", $link);

$result = mysql_query("SELECT * FROM packages");

$packages = array();
while ($row = mysql_fetch_array($result)) {
    $packages[] = new Package($row[0], $row[1], $row[2], $row[3], $row[4], $row[5]);
}


mysql_free_result($result);
?>

<html>
    <head>
        <script src="TrackPosition.js" type="text/javascript"></script>
        <script src="Distance.js" type="text/javascript"></script>
    </head>
    <body>
        <div class="output" id="output"></div>
       <script type="text/javascript">
           var s = <?php print $packages[0]->toJSON(); ?>; 

           document.write(distance(current_lat, current_long, s.lat, s.longs));

       </script>
    </body>
</html>