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我是新来的。我正在尝试制作一个应用程序，使用谷歌地图 API 计算两个地址之间的距离和行驶时间。

我的问题是 google DirectionsService() 似乎没有响应。我想不通。我一直在努力弄清楚一个星期。

我希望你们能提供帮助。问题似乎出在 gmapApi.js

这是我的代码。
默认.aspx

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs"           Inherits="_Default" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
<script type="text/javascript">
    function postbackObj() {
        var orig = document.getElementById('<%= txbOrigin.ClientID %>').value;
        var dist = document.getElementById('<%= txbDestination.ClientID %>').value;
        var temp = showLocation(orig, dist);
        __doPostBack('gmAPIObj',temp);
    }
</script>
    <script src="http://maps.googleapis.com/maps/api/js?sensor=false" type="text/javascript">< /script>
    <script type="text/javascript" src="gmapApi.js"></script>

</head>
<body>
<form id="form1" runat="server">
<div>
<asp:TextBox ID="txbOrigin" Text="" runat="server" />
<asp:TextBox ID="txbDestination" Text="" runat="server" />
<asp:Button ID="btnSubmit" runat="server" Text="Search" OnClientClick="postbackObj()"/>    

<p>
    < asp:Label runat="server" ID="lblPrint" />
</p>

</div>
</form>

</body>
</html>

gmapApi.js

function showLocation(orig, dist) {
var directionService = new google.maps.DirectionsService();
var t = "";
var request = {
    origin: orig,
    destination: dist,
    travelMode: google.maps.DirectionsTravelMode.DRIVING
};


directionService.route(request, function (response, status) {
    if (status != google.maps.DirectionsStatus.OK) {
        alert(status + "  \nreq. failed.");
    }
    else {
        t = request.origin + ';' + request.destination + ';' +  response.routes[0].legs[0].distance.value + ';' + response.routes[0].legs[0].duration.value;
    }
});

return t;
}

响应变量为null，状态变量在directionService.route（request，function（response，status）中为空字符串我试图更改为无锁。我试图将标签放置在没有锁的body标签中。

呈现的 html 代码。 

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head><title>

</title>
<script type="text/javascript">
    function postbackObj() {
        var orig = document.getElementById('txbOrigin').value;
        var dist = document.getElementById('txbDestination').value;
        var temp = showLocation(orig, dist);
        __doPostBack('gmAPIObj',temp);
    }
</script>
    <script src="http://maps.googleapis.com/maps/api/js?sensor=false" type="text/javascript"></script>
    <script type="text/javascript" src="gmapApi.js"></script>

</head>
<body>
<form method="post" action="Default.aspx" id="form1">
<div class="aspNetHidden">
<input type="hidden" name="__EVENTTARGET" id="__EVENTTARGET" value="" />
<input type="hidden" name="__EVENTARGUMENT" id="__EVENTARGUMENT" value="" />
<input type="hidden" name="__VIEWSTATE" id="__VIEWSTATE" value="/wEPDwULLTE2MjMyMzMwNTZkZHxi8IJlhy7bL8nAZqZfL2Vh4Yr8uF80ja6jX9Ypc87B" />
</div>

<script type="text/javascript">
//<![CDATA[
var theForm = document.forms['form1'];
if (!theForm) {
theForm = document.form1;
}
function __doPostBack(eventTarget, eventArgument) {
if (!theForm.onsubmit || (theForm.onsubmit() != false)) {
    theForm.__EVENTTARGET.value = eventTarget;
    theForm.__EVENTARGUMENT.value = eventArgument;
    theForm.submit();
}
}
//]]>
</script>


<div class="aspNetHidden">

<input type="hidden" name="__EVENTVALIDATION" id="__EVENTVALIDATION"   value="/wEWBALsorucDwLTmobsAwK0weWLAwLCi9reA32PxME86E6mQhRTgBkF7cdktbiURIpf/IzKvAs5PHwI" />
</div>
<div>
<input name="txbOrigin" type="text" value="tilst" id="txbOrigin" />
<input name="txbDestination" type="text" value="aarhus" id="txbDestination" />
<input type="submit" name="btnSubmit" value="Search" onclick="postbackObj();" id="btnSubmit" />    

<p>
    <span id="lblPrint"></span>
</p>

</div>
</form>

</body>
</html>

提前致谢。

4

1 回答 1

2

请求directionService是一个异步过程，你在函数内部的变量tshowLocation不会被调用修改directionService.route()

__doPostBack('gmAPIObj',t)而是从成功的回调中调用directionService.route()。

function postbackObj() {
    var orig = document.getElementById('txbOrigin').value;
    var dist = document.getElementById('txbDestination').value;
    showLocation(orig, dist);
}

//-----

function showLocation(orig, dist) {
var directionService = new google.maps.DirectionsService();
var t = "";
var request = {
    origin: orig,
    destination: dist,
    travelMode: google.maps.DirectionsTravelMode.DRIVING
};


directionService.route(request, function (response, status) {
    if (status != google.maps.DirectionsStatus.OK) {
        alert(status + "  \nreq. failed.");
    }
    else {
        t = request.origin + ';' + request.destination + ';' +  response.routes[0].legs[0].distance.value + ';' + response.routes[0].legs[0].duration.value;
       __doPostBack('gmAPIObj',t);
    }
});
}
于 2012-10-30T11:51:15.510 回答