DateTime difference between server and client
everyone! I'm solving next problem with time in my ASP.NET MVC project:
Problem: need to calculate difference between client DateTime and server DateTime. I have javascript function, that do Ajax query to server (DateController) with timeStamp parameter = getNow(), code of which is below.
getNow: function() {
var date = new Date();
return (date.getTime() + (date.getTimezoneOffset() * 60000));
}
Next, on server side I have DateController, in which I need to calculate dateTime difference in milliseconds:
....
var clientMs = long.Parse(Request.QueryString["t"]);
var dt1970 = new DateTime(1970, 1, 1, 0, 0, 0);
var msFrom1970 = (DateTime.Now - dt1970).TotalMilliseconds
+(DateTime.UtcNow - DateTime.Now).TotalMilliseconds;
var timeOffset = msFrom1970 -clientMs;
return new JsonResult
{
JsonRequestBehavior = JsonRequestBehavior.AllowGet,
Data = new { responseText = timeOffset.ToString()
};
}
But timeOffset is calculated wrong. I t开发者_C百科ry to check this logic in small console app:
class Program
{
static void Main(string[] args)
{
var clientMs = 1304411645875;
//value of clientMs I get from javaScript by using page
//http://www.w3schools.com/jsref/tryit.asp?filename=tryjsref_gettime
//with this script
/*
<HTML>
<body>
<script type="text/javascript">
var d=new Date();
document.write(d.getTime());
</script>
</body>
</HTML>
*/
var dt1970 = new DateTime(1970, 1, 1, 0, 0, 0);
var msFrom1970 = (DateTime.Now - dt1970).TotalMilliseconds
+(DateTime.UtcNow - DateTime.Now).TotalMilliseconds;
Console.WriteLine( msFrom1970);
Console.ReadLine();
}
}
Difference is about hours. Can someone show me my mistake or problem is occurred by something else?
You seem to be struggling with converting a javascript date to a C# date.
[Update] getUTCMilliseconds() only returns the milliseconds part of a date [/Update]
To pass the date in milliseconds to the server, use this function:
getNow: function() {
var date = new Date();
return date.getUTCMilliseconds();
}
And to convert this value of UTC milliseconds to a DateTime in .NET:
// Convert UTC milliseconds to System.DateTime
DateTime dtClient = new DateTime((millisecondsClient * TimeSpan.TicksPerMillisecond) + 621355968000000000);
// Test if this conversion is correct:
TimeSpan offset = DateTime.UtcNow - dtClient;
What you seem to be missing is the conversion from milliseconds to ticks.
References:
http://www.w3schools.com/jsref/jsref_getUTCMilliseconds.asp
http://twit88.com/blog/2011/01/23/net-datetime-from-milliseconds/
Daylight savings time prevents function's getTimezoneOffset() return from being a constant even for a given locale.
Maybe DateTime.Now greater than DateTime.UtcNow and (DateTime.UtcNow - DateTime.Now).TotalMilliseconds returns 0
加载中,请稍侯......
精彩评论