Get elapsed time since application start

Question

I am porting an app from ActionScript3.0 (Flex) to C# (WPF).AS3.0 has got a handy utility called getTimer() which returns time since Flash Virtual machine start in milliseconds.I was searching in C# through classes as

DateTime
DispatcherTimer
System.Diagnostics.Process
System.Diagnostics.Stopwatch

but found nothing like this.It seems a very basic feature to me.For example Unity3D which runs on Mono has something familiar. Do I miss some utility here?

Thanks in advance.

Solution

Process.GetCurrentProcess().StartTime is your friend.

..so to get elapsed time since start:

DateTime.UtcNow - Process.GetCurrentProcess().StartTime.ToUniversalTime()

alternatively, if you need more definition, System.Diagnostics.Stopwatch might be preferable. If so, start a stopwatch when your app starts:

Stopwatch sw = Stopwatch.StartNew();

then query the sw.Elapsed property during your execution run.

Comments

[as-cii]

Whether to choose one or the other is not a matter of precision but of needs instead. Process.GetCurrentProcess().StartTime will never be called at the same time of Stopwatch.StartNew()! So it depends on when the user want to start timing. :)

[Michael IV]

Are you sure Process.GetCurrentProcess returns time since the Application starts up? I just made a check: (DateTime.Now -Process.GetCurrentProcess().StartTime).TotalSeconds .At the moment the App is up I print the time to Console.It starts from 16-17 seconds.It is obviously too much because it took maximum 4 seconds for the App to start.

[spender]

Interesting. The docs seem to agree with me. If this really is the case, I'd say it merits a new question.

[JJS]

@MichaelIV - the large amount of time is pretty easy to replicate. Press F5. To get a concistently small amount of time, use CTRL + F5 (Start without Debugging). F5 (Run with Debugger) runs inside a AssemblyName.vshost.exe which maybe have been running longer than when you first 'start' your debugging session. Try using Process.GetCurrentProcess().ProcessName at the stdart of the program.

[Syaiful Nizam Yahya]

Process.GetCurrentProcess().StartTime doesnt work for me. Im not on Unity by the way. Stopwatch worked for me.

[ina]

can this be used for determining total time across all session or only current active session

[Vincent]

Stopwatch is much more reliable, DateTime.UtcNow - Process.GetCurrentProcess().StartTime.ToUniversalTime() is not reliable, because user may modify system time.