如何从存储在MySQL数据库中的坐标显示动画多个标记

时间：2016-09-03 01:35:50

标签： javascript php mysql google-maps google-maps-markers

我对使用谷歌地图与MySQL数据库中存储的地理位置/坐标有疑问。

代码示例：

<html>
<head>
<meta name="viewport" content="initial-scale=1.0, user-scalable=no"/>
<meta http-equiv="content-type" content="text/html; charset=UTF-8"/>
<title>TRACKING MARKERS</title>


<style>
html{height:100%;}
body{height:50%; width:50%;margin:0px;font-family: Helvetica,Arial;}
</style>
<script src="https://maps.googleapis.com/maps/api/js?key=MY-API-KEY&callback=initMap"></script>
<script type ="text/javascript" src="http://www.geocodezip.com/scripts/v3_epoly.js"></script>
<script type="text/javascript">

  var map;
  var directionDisplay;
  var directionsService;
  var stepDisplay;

  var position;
  var marker = [];
  var polyline = [];
  var poly2 = [];
  var poly = null;
  var startLocation = [];
  var endLocation = [];
  var timerHandle = [];


  var speed = 5, wait = 1;
  var infowindow = null;

  var myPano;   
  var panoClient;
  var nextPanoId;

  var startLoc = new Array();
  startLoc[0] = 'Berlin, Germany';
  startLoc[1] = 'Berlin, Germany';
  startLoc[2] = 'Berlin, Germany';
  startLoc[3] = 'Berlin, Germany';

  var endLoc = new Array();
  endLoc[0] = 'Zagreb, Croatia';
  endLoc[1] = 'Zagreb, Croatia';
  endLoc[2] = 'Zagreb, Croatia';
  endLoc[3] = 'Zagreb, Croatia';


  var Colors = ["#FF0000", "#00FF00", "#0000FF"];


function initialize() {  

  infowindow = new google.maps.InfoWindow(
    { 
      size: new google.maps.Size(150,50)
    });

    var myOptions = {
      zoom: 16,
      mapTypeId: google.maps.MapTypeId.ROADMAP
    }
    map = new google.maps.Map(document.getElementById("map_canvas"), myOptions);

    address = 'Sarajevo, Bosnia and Herzegovina'
    geocoder = new google.maps.Geocoder();
    geocoder.geocode( { 'address': address}, function(results, status) {
     map.fitBounds(results[0].geometry.viewport);

    }); 
  // setRoutes();
  } 


function createMarker(latlng, label, html) {
// alert("createMarker("+latlng+","+label+","+html+","+color+")");
    var contentString = '<b>'+label+'</b><br>'+html;
    var marker = new google.maps.Marker({
        position: latlng,
        map: map,
        title: label,
        zIndex: Math.round(latlng.lat()*-100000)<<5
        });
        marker.myname = label;


    google.maps.event.addListener(marker, 'click', function() {
        infowindow.setContent(contentString); 
        infowindow.open(map,marker);
        });
    return marker;
}  

function setRoutes(){   

    var directionsDisplay = new Array();

    for (var i=0; i< startLoc.length; i++){

    var rendererOptions = {
        map: map,
        suppressMarkers : true,
        preserveViewport: true
    }
    directionsService = new google.maps.DirectionsService();

    var travelMode = google.maps.DirectionsTravelMode.DRIVING;  

    var request = {
        origin: startLoc[i],
        destination: endLoc[i],
        travelMode: travelMode
    };  

        directionsService.route(request,makeRouteCallback(i,directionsDisplay[i]));

    }   


    function makeRouteCallback(routeNum,disp){
        if (polyline[routeNum] && (polyline[routeNum].getMap() != null)) {
         startAnimation(routeNum);
         return;
        }
        return function(response, status){

          if (status == google.maps.DirectionsStatus.OK){

            var bounds = new google.maps.LatLngBounds();
            var route = response.routes[0];
            startLocation[routeNum] = new Object();
            endLocation[routeNum] = new Object();


            polyline[routeNum] = new google.maps.Polyline({
            path: [],
            strokeColor: '#FFFF00',
            strokeWeight: 3
            });

            poly2[routeNum] = new google.maps.Polyline({
            path: [],
            strokeColor: '#FFFF00',
            strokeWeight: 3
            });     


            // For each route, display summary information.
            var path = response.routes[0].overview_path;
            var legs = response.routes[0].legs;


            disp = new google.maps.DirectionsRenderer(rendererOptions);     
            disp.setMap(map);
            disp.setDirections(response);


            //Markers               
            for (i=0;i<legs.length;i++) {
              if (i == 0) { 
                startLocation[routeNum].latlng = legs[i].start_location;
                startLocation[routeNum].address = legs[i].start_address;
                // marker = google.maps.Marker({map:map,position: startLocation.latlng});
                marker[routeNum] = createMarker(legs[i].start_location,"start",legs[i].start_address,"green");
              }
              endLocation[routeNum].latlng = legs[i].end_location;
              endLocation[routeNum].address = legs[i].end_address;
              var steps = legs[i].steps;

              for (j=0;j<steps.length;j++) {
                var nextSegment = steps[j].path;                
                var nextSegment = steps[j].path;

                for (k=0;k<nextSegment.length;k++) {
                    polyline[routeNum].getPath().push(nextSegment[k]);
                    //bounds.extend(nextSegment[k]);
                }

              }
            }

         }       

         polyline[routeNum].setMap(map);
         //map.fitBounds(bounds);
         startAnimation(routeNum);  

    } // else alert("Directions request failed: "+status);

  }

}

    var lastVertex = 1;
    var stepnum=0;
    var step = 50; // 5; // metres
    var tick = 100; // milliseconds
    var eol= [];
//----------------------------------------------------------------------                
 function updatePoly(i,d) {
 // Spawn a new polyline every 20 vertices, because updating a 100-vertex poly is too slow
    if (poly2[i].getPath().getLength() > 20) {
          poly2[i]=new google.maps.Polyline([polyline[i].getPath().getAt(lastVertex-1)]);
          // map.addOverlay(poly2)
        }

    if (polyline[i].GetIndexAtDistance(d) < lastVertex+2) {
        if (poly2[i].getPath().getLength()>1) {
            poly2[i].getPath().removeAt(poly2[i].getPath().getLength()-1)
        }
            poly2[i].getPath().insertAt(poly2[i].getPath().getLength(),polyline[i].GetPointAtDistance(d));
    } else {
        poly2[i].getPath().insertAt(poly2[i].getPath().getLength(),endLocation[i].latlng);
    }
 }
//----------------------------------------------------------------------------

function animate(index,d) {
   if (d>eol[index]) {

      marker[index].setPosition(endLocation[index].latlng);
      return;
   }
    var p = polyline[index].GetPointAtDistance(d);

    //map.panTo(p);
    marker[index].setPosition(p);
    updatePoly(index,d);
    timerHandle[index] = setTimeout("animate("+index+","+(d+step)+")", tick);
}

//-------------------------------------------------------------------------

function startAnimation(index) {
        if (timerHandle[index]) clearTimeout(timerHandle[index]);
        eol[index]=polyline[index].Distance();
        map.setCenter(polyline[index].getPath().getAt(0));

        poly2[index] = new google.maps.Polyline({path: [polyline[index].getPath().getAt(0)], strokeColor:"#FFFF00", strokeWeight:3});

        timerHandle[index] = setTimeout("animate("+index+",50)",2000);  // Allow time for the initial map display
}

//----------------------------------------------------------------------------    



</script>
</head>
<body onload="initialize()">

<div id="tools">

    <button onclick="setRoutes();">Start</button>

</div>

<div id="map_canvas" style="width:100%;height:100%;"></div>
</body>
</html>

代码的这一特定部分是我的问题：

 var startLoc = new Array();
  startLoc[0] = 'Berlin, Germany';
  startLoc[1] = 'Berlin, Germany';
  startLoc[2] = 'Berlin, Germany';
  startLoc[3] = 'Berlin, Germany';

  var endLoc = new Array();
  endLoc[0] = 'Zagreb, Croatia';
  endLoc[1] = 'Zagreb, Croatia';
  endLoc[2] = 'Zagreb, Croatia';
  endLoc[3] = 'Zagreb, Croatia';

假设Loc0，loc1，loc2和loc3是列车组成的一部分 - 机车和3辆铁路货车;他们每个人都有一个跟踪设备，可以在数据库中发送地理位置。

可以，如果可以 - 有人知道如何 - 在上面的示例中使用数据库中的数据而不是硬编码的gelocations吗？

2 个答案:

答案 0 :(得分：0)

您可以从数据库中检索这些gelocation记录，并在PHP脚本，Jsp等Web脚本语言的帮助下将它们放入json字符串中。

然后，你的javascript获取这些数据并使用它们（Ajax应该更好）

答案 1 :(得分：0)

查看文档中的完整指南Using PHP/MySQL with Google Maps。

Outputting XML with PHP

首先，您应该将数据库连接信息放在单独的文件中。每当您使用PHP访问数据库时，这通常是一个好主意，因为它会将您的机密信息保存在您不想分享的文件中。在公共论坛中，我们偶尔会看到人们在尝试调试XML输出代码时不小心发布了他们的数据库连接信息。该文件应如下所示，但填写了您自己的数据库信息（phpsqlajax_dbinfo.php）：

<?php
$username="username";
$password="password";
$database="username-databaseName";
?>

<?php
require("phpsqlajax_dbinfo.php");

// Start XML file, create parent node
$doc = domxml_new_doc("1.0");
$node = $doc->create_element("markers");
$parnode = $doc->append_child($node);

// Opens a connection to a MySQL server
$connection=mysql_connect ('localhost', $username, $password);
if (!$connection) {
  die('Not connected : ' . mysql_error());
}

// Set the active MySQL database
$db_selected = mysql_select_db($database, $connection);
if (!$db_selected) {
  die ('Can\'t use db : ' . mysql_error());
}

// Select all the rows in the markers table
$query = "SELECT * FROM markers WHERE 1";
$result = mysql_query($query);
if (!$result) {
  die('Invalid query: ' . mysql_error());
}

header("Content-type: text/xml");

// Iterate through the rows, adding XML nodes for each
while ($row = @mysql_fetch_assoc($result)){
  // ADD TO XML DOCUMENT NODE
  $node = $doc->create_element("marker");
  $newnode = $parnode->append_child($node);

  $newnode->set_attribute("name", $row['name']);
  $newnode->set_attribute("address", $row['address']);
  $newnode->set_attribute("lat", $row['lat']);
  $newnode->set_attribute("lng", $row['lng']);
  $newnode->set_attribute("type", $row['type']);
}

$xmlfile = $doc->dump_mem();
echo $xmlfile;

?>

以下是another guide，其中包含示例代码以供其他参考。

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