javascript navigator.geolocation.watchPosition - 频率
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/24019286/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
navigator.geolocation.watchPosition - frequency
提问by mr.x
I tried this code :
我试过这个代码：
<!DOCTYPE html>
<html>
<head>
<title>Location Location Location</title>
<script type="text/javascript" charset="utf-8">
var watchID = null;
// PhoneGap is ready
//
function f() {
// Update every 1 ms seconds
var options = {enableHighAccuracy: true,timeout: 5000,maximumAge: 0,desiredAccuracy: 0, frequency: 1 };
watchID = navigator.geolocation.watchPosition(onSuccess, onError, options);
}
// onSuccess Geolocation
//
function onSuccess(position) {
var xmlhttp;
if (window.XMLHttpRequest){// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp=new XMLHttpRequest();
}else{// code for IE6, IE5
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
var str = 'Latitude: ' + position.coords.latitude + '<br>' +
'Longitude: ' + position.coords.longitude + '<br>' +
'Timestamp: ' + position.timestamp + '<br>' ;
var url = "load.php";
var params = "data="+str;
xmlhttp.open("GET", url+"?"+params, true);
document.body.innerHTML += str;
document.writeln("line 33");
xmlhttp.send();
//document.writeln("send");
//document.writeln(str);
}
// clear the watch that was started earlier
//
function clearWatch() {
if (watchID != null) {
navigator.geolocation.clearWatch(watchID);
watchID = null;
}
}
// onError Callback receives a PositionError object
//
function onError(error) {
alert('code: ' + error.code + '\n' +
'message: ' + error.message + '\n');
}
</script>
</head>
<body>
<p id="geolocation">Watching geolocation...</p>
<button onclick="f();"> Watch</button>
</body>
</html>
you can see that i add
你可以看到我添加
var options = {......, frequency: 1 };
watchID = navigator.geolocation.watchPosition(onSuccess, onError, options);
But I am getting new result if and only if I enter to tab and exit and enter agin.
但是当且仅当我进入 tab 并退出并输入 agin 时，我才会得到新的结果。
What can I do?
我能做什么？
回答by RamRaider
The spec makes no mention of a frequency option which suggests that this parameter is being ignored. W3C Geolocation spec
该规范没有提及频率选项，这表明该参数被忽略。W3C 地理定位规范
回答by Luizgrs
You code seems to be working fine: http://jsfiddle.net/Mgk9J/1/
你的代码似乎工作正常：http: //jsfiddle.net/Mgk9J/1/
I tested it in Android and when I move the cellphone new lines came up. However in chrome desktop it plots new lines when I change tabs even though they're identical to the last ones, according to the spec this isn't the correctly behavior.
我在 Android 上进行了测试，当我移动手机时，新线路出现了。但是，在 chrome 桌面中，即使它们与上一个相同，但当我更改选项卡时，它会绘制新行，根据规范，这不是正确的行为。
It makes a bit of sense for the desktop version do not plot new lines anyway, the computer isn't moving so new success calbacks execution should not be fired.
无论如何，桌面版本不绘制新行是有意义的，计算机没有移动，因此不应触发新的成功回调执行。
<html><head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<title> - jsFiddle demo</title>
<script type="text/javascript" src="/js/lib/dummy.js"></script>
<link rel="stylesheet" type="text/css" href="/css/result-light.css">
<style type="text/css">
</style>
<script type="text/javascript">//<![CDATA[
window.onload=function(){
var watchID = null;
// PhoneGap is ready
//
function f() {
// Update every 1 ms seconds
var options = {enableHighAccuracy: true,timeout: 5000,maximumAge: 0,desiredAccuracy: 0, frequency: 1 };
watchID = navigator.geolocation.watchPosition(onSuccess, onError, options);
}
// onSuccess Geolocation
//
function onSuccess(position) {
var str = 'Latitude: ' + position.coords.latitude + '<br>' +
'Longitude: ' + position.coords.longitude + '<br>' +
'Timestamp: ' + position.timestamp + '<br>\r\n' ;
document.getElementById('result').value += str;
}
// clear the watch that was started earlier
//
function clearWatch() {
if (watchID != null) {
navigator.geolocation.clearWatch(watchID);
watchID = null;
}
}
// onError Callback receives a PositionError object
//
function onError(error) {
alert('code: ' + error.code + '\n' +
'message: ' + error.message + '\n');
}
document.getElementById('button').addEventListener('click', f);
}//]]>
</script>
</head>
<body>
<p id="geolocation">Watching geolocation...</p>
<button id="button"> Watch</button>
<textarea id="result" cols="100" rows="10"></textarea>
</body></html>
