Timer class Null safety
A count-down timer that can be configured to fire once or repeatedly.
The timer counts down from the specified duration to 0. When the timer reaches 0, the timer invokes the specified callback function. Use a periodic timer to repeatedly count down the same interval.
A negative duration is treated the same as a duration of 0. If the duration is statically known to be 0, consider using run.
Frequently the duration is either a constant or computed as in the following example (taking advantage of the multiplication operator of the Duration class):
const timeout = const Duration(seconds: 3);
const ms = const Duration(milliseconds: 1);
startTimeout([int milliseconds]) {
var duration = milliseconds == null ? timeout : ms * milliseconds;
return new Timer(duration, handleTimeout);
}
...
void handleTimeout() { // callback function
...
}
Note: If Dart code using Timer is compiled to JavaScript, the finest granularity available in the browser is 4 milliseconds.
See Stopwatch for measuring elapsed time.
Constructors
Properties
- hashCode → int
-
The hash code for this object. [...]
read-only, inherited
- isActive → bool
-
Returns whether the timer is still active. [...]
read-only
- runtimeType → Type
-
A representation of the runtime type of the object.
read-only, inherited
- tick → int
-
The number of durations preceding the most recent timer event. [...]
read-only
Methods
-
cancel(
) → void - Cancels the timer. [...]
-
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a non-existent method or property is accessed. [...]
inherited
-
toString(
) → String -
Returns a string representation of this object.
inherited
Operators
-
operator ==(
Object other) → bool -
The equality operator. [...]
inherited