(这是我发表的另一篇文章的一部分,PhoneGap 中的 Google Maps API v3:移动后标记无法正确绘制)。我一直在使用 PhoneGap 在 Android 上开发 Google Maps API 3 应用程序。它应该跟踪用户位置并用标记和周围的圆圈标记该位置。我一直在 Android 2.3 上开发这个,并且运行良好。然后我升级到了 Android 4.x 的手机,我想它仍然运行良好。
上周,当我移动标记和圆圈时,我开始注意到谷歌地图做了一些奇怪的事情。它似乎创建了一个重复的标记和圆圈,而不是仅仅移动它们。在另一篇文章中,我得到了标记问题的答案,但没有得到圆的答案。有时,如果我更改缩放比例,重复的圆圈似乎就会消失。而且,它偶尔会从顶部画出一些奇怪的切线。请参阅下面的图片。
在我的手机上收到 Android 更新至版本 4.1.1 后不久,我就开始注意到这一点。不确定这是否相关,我找不到有关问题的任何信息。
我将地图和音位间隙代码减少到一个相当小的样本,并且它仍在这样做。我很确定这与phonegap无关。无论如何,我将 PhoneGap 升级到 2.2,但正如预期的那样,它没有帮助。谁能告诉我移动圆圈时是否做错了什么?
我尝试的一个解决方案是在移动它之前隐藏圆圈,然后在移动它之后再次显示它。这似乎解决了重复和切线问题,但它使地图闪烁,当你每 3 秒左右移动它时,这真的很烦人。所以这似乎不是一个可以接受的解决方案。测试代码如下。请注意,我在测试代码中删除了我的 Google 地图 API 密钥。
我还了解到,使其正确重绘的一种方法是拖动地图,使任何圆圈的任何部分都不可见。然后,当我将其拖回以使圆圈可见时,它会被重新绘制为一个正确的圆圈。
谢谢,埃里克
<!DOCTYPE HTML>
<html>
<head>
<title>Marker Test</title>
<meta name="viewport" content="initial-scale=1.0, user-scalable=no" />
<style type="text/css">
html {height: 100%}
body {height: 100%; margin:0; padding:0}
#map_canvas {height: 100%}
</style>
<script type="text/javascript" charset="utf-8" src="js/phonegap.js"></script>
<script type="text/javascript" charset="utf-8" src="http://maps.googleapis.com/maps/api/js?key=YOUR_KEY_HERE&sensor=true"></script>
<script type="text/javascript" charset="utf-8">
// Wait for PhoneGap to load
//
document.addEventListener("deviceready", onDeviceReady, false);
// globals
var watchID = null;
var map = null;
var myLocationMarker = null;
var searchCircle = null;
// PhoneGap is ready
//
function onDeviceReady() {
startGPS();
}
function onUnLoad() {
console.log("clearing watch " + watchID);
navigator.geolocation.clearWatch(watchID);
}
function startGPS() {
console.log("In startGPS");
var refreshMilliseconds = 5000;
var options = { frequency: refreshMilliseconds, enableHighAccuracy: true};
watchID = navigator.geolocation.watchPosition(onGPSSuccess, onGPSError, options);
// create Google map
var mapOptions = {
zoom: 14,
mapTypeId: google.maps.MapTypeId.ROADMAP
};
map = new google.maps.Map(document.getElementById("map_canvas"), mapOptions);
myLocationMarker = new google.maps.Marker({
title: 'This is me!',
zIndex: 90,
optimized: false,
map:map
});
searchCircle = new google.maps.Circle({
fillColor: '#c0e4dd',
strokeColor: '#f15f22',
fillOpacity: 0.5,
radius: 1500,
map:map
});
}
var onGPSSuccess = function(p) {
// get the new coordinates
var lat = p.coords.latitude;
var lng = p.coords.longitude;
console.log("watch ID " + watchID);
// now that we have the coordinates, we can move the marker and circle on the Google Map
MoveMarkerAndCircle(lat, lng);
};
var MoveMarkerAndCircle = function(lat, lng) {
var myLocation = new google.maps.LatLng(lat, lng);
myLocationMarker.setPosition(myLocation);
// searchCircle.setVisible(false);
searchCircle.setCenter(myLocation);
// searchCircle.setVisible(true);
map.setCenter(myLocation);
}
var onGPSError = function() {
console.log("GPS Error");
};
var GenerateFakeMovement = function() {
var currentPosition = myLocationMarker.getPosition();
var newLat = currentPosition.lat() + 0.01;
var newLng = currentPosition.lng() + 0.01;
MoveMarkerAndCircle(newLat, newLng);
}
</script>
</head>
<body style="height:100%;text-align:center" onunload="onUnLoad()">
<div id="map_canvas" style="width: 100%;height:80%"></div>
<a href='#' onclick="GenerateFakeMovement();" style="padding-top:5px">MAKE FAKE MOVEMENT</a>
</body>
</html>
<!DOCTYPE HTML>
<html>
<head>
<title>Marker Test</title>
<meta name="viewport" content="initial-scale=1.0, user-scalable=no" />
<style type="text/css">
html {height: 100%}
body {height: 100%; margin:0; padding:0}
#map_canvas {height: 100%}
</style>
<script type="text/javascript" charset="utf-8" src="http://maps.googleapis.com/maps/api/js?v=3&sensor=true"></script>
<script type="text/javascript" charset="utf-8">
var watchID = null;
var map = null;
var myLocationMarker = null;
var searchCircle = null;
function onDeviceReady() {
startGPS();
}
function onUnLoad() {
console.log("clearing watch " + watchID);
navigator.geolocation.clearWatch(watchID);
}
function startGPS() {
console.log("In startGPS");
var refreshMilliseconds = 5000;
var options = { frequency: refreshMilliseconds, enableHighAccuracy: true};
if(watchID ==null)
watchID = navigator.geolocation.watchPosition(onGPSSuccess, onGPSError, options);
// create Google map
var mapOptions = {
zoom: 14,
mapTypeId: google.maps.MapTypeId.ROADMAP
};
map = new google.maps.Map(document.getElementById("map_canvas"), mapOptions);
myLocationMarker = new google.maps.Marker({
title: 'This is me!',
zIndex: 90,
optimized: false,
map:map
});
searchCircle = new google.maps.Circle({
fillColor: '#c0e4dd',
strokeColor: '#f15f22',
fillOpacity: 0.5,
radius: 1500,
map:map
});
}
var onGPSSuccess = function(p) {
// get the new coordinates
var lat = p.coords.latitude;
var lng = p.coords.longitude;
console.log("watch ID " + watchID);
// now that we have the coordinates, we can move the marker and circle on the Google Map
MoveMarkerAndCircle(lat, lng);
};
var MoveMarkerAndCircle = function(lat, lng) {
var myLocation = new google.maps.LatLng(lat, lng);
myLocationMarker.setPosition(myLocation);
// searchCircle.setVisible(false);
searchCircle.setCenter(myLocation);
// searchCircle.setVisible(true);
map.setCenter(myLocation);
}
var onGPSError = function() {
console.log("GPS Error");
};
function GenerateFakeMovement() {
var currentPosition = myLocationMarker.getPosition();
var newLat = currentPosition.lat() + 0.01;
var newLng = currentPosition.lng() + 0.01;
MoveMarkerAndCircle(newLat, newLng);
}
</script>
</head>
<body style="height:100%;text-align:center" onload="onDeviceReady()" onunload="onUnLoad()">
<div id="map_canvas" style="width: 100%;height:80%"></div>
<a href='#' onclick="GenerateFakeMovement();" style="padding-top:5px">MAKE FAKE MOVEMENT</a>
</body>
</html>
可能与您的问题不完全相关,但如果您将圆圈绑定到标记,则无需手动设置圆圈位置。
if (myMarker == undefined) {
myMarker = new google.maps.Marker({
position: mouseEvent.latLng,
title: 'My Position',
map: map,
draggable: true
});
var circle = new google.maps.Circle({
map: map,
radius: 100000, // 100 km
fillOpacity: 0.1,
strokeOpacity: 0.5,
strokeWeight: 1
});
circle.bindTo('center', myMarker, 'position'); //This will set the circle bound to the marker at center
}
所以你只需要更新标记的位置即可。 希望这有帮助。
我希望我将其作为“答案”发布是正确的。我仍然遇到这个问题,但我已经将自己的示例缩小到了这一点,似乎很明显,这只是 Android 4.1.1 上的 Google Maps API v3 的问题。缩小测试用例的代码如下,不再涉及 PhoneGap。
我已将测试页面发布到网上: http://kcwebprogrammers.com/MarkerTest-NoGps.html
如果您在 Windows(Chrome 或 IE)中或使用 Android 2.3 上的互联网浏览器浏览,则移动圆圈就可以了。如果您在Android 4.1.1上使用互联网浏览器浏览到同一页面,那么您会看到移动圆圈后原始圆圈仍然可见,从而导致两个圆圈。所以我已将问题发布到 Google 地图问题列表中。
感谢以上的建议。如果有人认为我应该对这篇文章做任何不同的事情,请告诉我。
<!DOCTYPE HTML>
<html>
<head>
<title>Marker Test</title>
<meta name="viewport" content="initial-scale=1.0, user-scalable=no" />
<style type="text/css">
html {height: 100%}
body {height: 100%; margin:0; padding:0}
#map_canvas {height: 100%}
</style>
<script type="text/javascript" charset="utf-8" src="http://maps.googleapis.com/maps/api/js?key=YOUR_KEY_HERE&sensor=true"></script>
<script type="text/javascript" charset="utf-8">
// globals
var watchID = null;
var map = null;
var myLocationMarker = null;
var searchCircle = null;
var myLocation = null;
function onLoad() {
startGPS();
}
function onUnLoad() {
console.log("clearing watch " + watchID);
}
function startGPS() {
// simulate getting position from GPS
myLocation = new google.maps.LatLng(39, -90);
// create Google map
var mapOptions = {
zoom: 14,
mapTypeId: google.maps.MapTypeId.ROADMAP,
center:myLocation
};
map = new google.maps.Map(document.getElementById("map_canvas"), mapOptions);
google.maps.event.trigger(map, 'resize');
myLocationMarker = new google.maps.Marker({
title: 'This is me!',
zIndex: 90,
optimized: false,
map:map,
position: myLocation
});
searchCircle = new google.maps.Circle({
fillColor: '#c0e4dd',
strokeColor: '#f15f22',
fillOpacity: 0.5,
radius: 1500,
map:map,
center:myLocation
});
// using bindTo instead does not fix the problem
// searchCircle.bindTo('center', myLocationMarker, 'position'); //This will set the circle bound to the marker at center
}
var MoveMarkerAndCircle = function(lat, lng) {
myLocation = new google.maps.LatLng(lat, lng);
myLocationMarker.setPosition(myLocation);
// set circle invisible before moving and visible after does fix redraw for 4.1.1
// but causes some annoying flashing of the circle for 4.1.1 and everything else
// searchCircle.setVisible(false);
searchCircle.setCenter(myLocation);
// searchCircle.setVisible(true);
}
var GenerateFakeMovement = function() {
var currentPosition = myLocationMarker.getPosition();
var newLat = currentPosition.lat() + 0.001;
var newLng = currentPosition.lng() + 0.001;
MoveMarkerAndCircle(newLat, newLng);
}
</script>
</head>
<body style="height:100%;text-align:center" onunload="onUnLoad()" onload="startGPS()">
<div id="map_canvas" style="width: 100%;height:90%"></div>
<a href='#' onclick="GenerateFakeMovement();" style="padding-top:5px">MOVE MARKER AND CIRCLE</a>
</body>
</html>