Stopwatch.Start Method
[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]
Starts, or resumes, measuring elapsed time for an interval.
Assembly: System (in System.dll)
In a typical Stopwatch scenario, you call the Start method, eventually call the Stop method, and then you check the elapsed time using the Elapsed property.
Once started, a Stopwatch timer measures the current interval, in elapsed timer ticks, until the instance is stopped or reset. Starting a Stopwatch that is already running does not change the timer state or reset the elapsed time properties.
When a Stopwatch instance measures more than one interval, the Start method resumes measuring time from the current elapsed time value. A Stopwatch instance calculates and retains the cumulative elapsed time across multiple time intervals, until the instance is reset. Use the Reset() method before calling Start to clear the cumulative elapsed time in a Stopwatch instance.