dart:core

Stopwatch class

A stopwatch which measures time while it's running.

A stopwatch is either running or stopped. It measures the elapsed time that passes while the stopwatch is running.

When a stopwatch is initially created, it is stopped and has measured no elapsed time.

The elapsed time can be accessed in various formats using elapsed, elapsedMilliseconds, elapsedMicroseconds or elapsedTicks.

The stopwatch is started by calling start.

Example:

final stopwatch = Stopwatch();
print(stopwatch.elapsedMilliseconds); // 0
print(stopwatch.isRunning); // false
stopwatch.start();
print(stopwatch.isRunning); // true

To stop or pause the stopwatch, use stop. Use start to continue again when only pausing temporarily.

stopwatch.stop();
print(stopwatch.isRunning); // false
Duration elapsed = stopwatch.elapsed;
await Future.delayed(const Duration(seconds: 1));
assert(stopwatch.elapsed == elapsed); // No measured time elapsed.
stopwatch.start(); // Continue measuring.

The reset method sets the elapsed time back to zero. It can be called whether the stopwatch is running or not, and doesn't change whether it's running.

// Do some work.
stopwatch.stop();
print(stopwatch.elapsedMilliseconds); // Likely > 0.
stopwatch.reset();
print(stopwatch.elapsedMilliseconds); // 0

Constructors

Stopwatch()

Creates a Stopwatch in stopped state with a zero elapsed count.

Properties

elapsed → Duration

read-only

The elapsedTicks counter converted to a Duration.

elapsedMicroseconds → int

read-only

The elapsedTicks counter converted to microseconds.

elapsedMilliseconds → int

read-only

The elapsedTicks counter converted to milliseconds.

elapsedTicks → int

read-only

The elapsed number of clock ticks since calling start while the Stopwatch is running.

frequency → int

read-only

Frequency of the elapsed counter in Hz.

hashCode → int

read-only, inherited

The hash code for this object.

isRunning → bool

read-only

Whether the Stopwatch is currently running.

runtimeType → Type

read-only, inherited

A representation of the runtime type of the object.

Methods

noSuchMethod(Invocation invocation) → dynamic

inherited

Invoked when a non-existent method or property is accessed.

reset() → void

Resets the elapsed count to zero.

start() → void

Starts the Stopwatch.

stop() → void

Stops the Stopwatch.

toString() → String

inherited

A string representation of this object.

Operators

operator ==(Object other) → bool

inherited

The equality operator.