Stopwatch.StartNew Method

Definition

Namespace:

System.Diagnostics

Assemblies:

netstandard.dll, System.Runtime.dll

Source:

Stopwatch.cs

Initializes a new Stopwatch instance, sets the elapsed time property to zero, and starts measuring elapsed time.

C#

public static System.Diagnostics.Stopwatch StartNew();

Returns

Stopwatch

A Stopwatch that has just begun measuring elapsed time.

Examples

The following example uses the Stopwatch class to measure the performance of four different implementations for parsing an integer from a string. This code example is part of a larger example provided for the Stopwatch class.

C#

long ticksThisTime = 0;
int inputNum;
Stopwatch timePerParse;

switch (operation)
{
    case 0:
        // Parse a valid integer using
        // a try-catch statement.

        // Start a new stopwatch timer.
        timePerParse = Stopwatch.StartNew();

        try
        {
            inputNum = Int32.Parse("0");
        }
        catch (FormatException)
        {
            inputNum = 0;
        }

        // Stop the timer, and save the
        // elapsed ticks for the operation.

        timePerParse.Stop();
        ticksThisTime = timePerParse.ElapsedTicks;
        break;
    case 1:
        // Parse a valid integer using
        // the TryParse statement.

        // Start a new stopwatch timer.
        timePerParse = Stopwatch.StartNew();

        if (!Int32.TryParse("0", out inputNum))
        {
            inputNum = 0;
        }

        // Stop the timer, and save the
        // elapsed ticks for the operation.
        timePerParse.Stop();
        ticksThisTime = timePerParse.ElapsedTicks;
        break;
    case 2:
        // Parse an invalid value using
        // a try-catch statement.

        // Start a new stopwatch timer.
        timePerParse = Stopwatch.StartNew();

        try
        {
            inputNum = Int32.Parse("a");
        }
        catch (FormatException)
        {
            inputNum = 0;
        }

        // Stop the timer, and save the
        // elapsed ticks for the operation.
        timePerParse.Stop();
        ticksThisTime = timePerParse.ElapsedTicks;
        break;
    case 3:
        // Parse an invalid value using
        // the TryParse statement.

        // Start a new stopwatch timer.
        timePerParse = Stopwatch.StartNew();

        if (!Int32.TryParse("a", out inputNum))
        {
            inputNum = 0;
        }

        // Stop the timer, and save the
        // elapsed ticks for the operation.
        timePerParse.Stop();
        ticksThisTime = timePerParse.ElapsedTicks;
        break;

    default:
        break;
}

Remarks

This method is equivalent to calling the Stopwatch constructor and then calling Start on the new instance.

Applies to

See also

• Start()
• Stop()
• IsRunning
• Reset()