Google Earth API链接.setHref在使用变量时不起作用

Google Earth API link.setHref not working when using variable

本文关键字：变量 不起作用 Earth API 链接 setHref Google      更新时间：2023-09-26

变量正在获取正确的数据，但在href参数中不起作用。我添加了一个带有变量的按钮，以便在浏览器中查看它。如果我把硬代码的值，它是有注释的，它是有效的。

<?php
@session_start();
$idcoord = $_GET['search_fd0'];
$kmlpath = "http://nonprasa.t15.org/kml/PR" . $idcoord . "/doc.kml";
?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8"/>
    <title>Google Earth API Sample</title>
<script src="http://www.google.com/jsapi?key=ABQIAAAAuPsJpk3MBtDpJ4G8cqBnjRRaGTYH6UMl8mADNa0YKuWNNa8VNxQCzVBXTx2DYyXGsTOxpWhvIG7Djw" type="text/javascript"></script>
<script type="text/javascript">
      function addSampleButton(caption, clickHandler) {
    var btn = document.createElement('input');
    btn.type = 'button';
    btn.value = caption;
    if (btn.attachEvent)
      btn.attachEvent('onclick', clickHandler);
    else
      btn.addEventListener('click', clickHandler, false);
    // add the button to the Sample UI
    document.getElementById('sample-ui').appendChild(btn);
  }
  function addSampleUIHtml(html) {
    document.getElementById('sample-ui').innerHTML += html;
  }
</script>
<script type="text/javascript">
var ge;
google.load("earth", "1");
function init() {
//  var kmlfile = ''"<?php echo $kmlpath; ?>'"';
 var kmlfile = '<?php echo $kmlpath;?>'; 
  google.earth.createInstance('map3d', initCallback, failureCallback);

  addSampleButton(kmlfile, buttonClick);
}
function initCallback(instance) {
  ge = instance;
  ge.getWindow().setVisibility(true);
  // add a navigation control
  ge.getNavigationControl().setVisibility(ge.VISIBILITY_AUTO);
  // add some layers
  ge.getLayerRoot().enableLayerById(ge.LAYER_BORDERS, true);
  ge.getLayerRoot().enableLayerById(ge.LAYER_ROADS, true);

  createNetworkLink();
  document.getElementById('installed-plugin-version').innerHTML =
    ge.getPluginVersion().toString();
}
function failureCallback(errorCode) {
}
function createNetworkLink() {
  var networkLink = ge.createNetworkLink("");
  networkLink.setDescription("NetworkLink open to fetched content");
  networkLink.setName("Open NetworkLink");
  networkLink.setFlyToView(true);
  // create a Link object
  var link = ge.createLink("");
 //link.setHref("http://nonprasa.t15.org/kml/PR0302013/doc.kml);
  link.setHref (kmlfile);

  // attach the Link to the NetworkLink
  networkLink.setLink(link);
  // add the NetworkLink feature to Earth
  ge.getFeatures().appendChild(networkLink);
    // look at the placemark we created
  var la = ge.createLookAt('');
  la.set(18, -67,
    0, // altitude
ge.ALTITUDE_RELATIVE_TO_GROUND,
0, // heading
0, // straight-down tilt
1500 // range (inverse of zoom)
);
  ge.getView().setAbstractView(la);
}
function buttonClick() {
// Get the current view.
var lookAt = ge.getView().copyAsLookAt(ge.ALTITUDE_RELATIVE_TO_GROUND);
// Zoom out to x times the current range.
lookAt.setRange(lookAt.getRange() * 5.0);
// Update the view in Google Earth.
ge.getView().setAbstractView(lookAt);
}
</script>
  </head>
  <body onload="init()" style="font-family: arial, sans-serif; font-size: 8px; border: 0;">
    <div id="sample-ui"></div> 
    <div id="map3d" style="width: 1200px; height: 800px;"></div>
    <br>
    <div>Installed Plugin Version: <span id="installed-plugin-version" style="font-weight: bold;">Loading...</span></div>
  </body>

javascript变量kmlfile是init函数的本地变量，因此当您尝试在createNetworkLink函数中使用它时，它总是未定义的。

为了强调我的意思，请看以下内容，为了清晰起见，我删除了其他代码。。。

function init() {
  var kmlfile = '<?php echo $kmlpath;?>'; // kmlfile defined here
}
function createNetworkLink() {
  link.setHref(kmlfile); // kmlfile is undefined here
  alert(kmlfile); // this would have told you as much...
}

要修复它，可以将kmlfile设置为全局变量，以便它在createNetworkLink函数的范围内可用。要做到这一点，只需在init方法之外创建变量，就像使用ge变量一样。

再次，为了清楚起见，请删除其他代码并查看以下内容。

<script type="text/javascript">
var ge;
var kmlfile; // kmlfile defined here
function init() {
  kmlfile = '<?php echo $kmlpath;?>'; // set the variable 
}
function createNetworkLink() {
  link.setHref(kmlfile); // kmlfile is now available here
}
</script>
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