Starts, or resumes, measuring elapsed time for an interval.
Assembly: System (in System.dll)
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 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 to clear the cumulative elapsed time in a Stopwatch instance. Use the Restart method to Reset and the Stopwatch with a single command.
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.