LinearProgressIndicator class

A Material Design linear progress indicator, also known as a progress bar.

A widget that shows progress along a line. There are two kinds of linear progress indicators:

• Determinate. Determinate progress indicators have a specific value at each point in time, and the value should increase monotonically from 0.0 to 1.0, at which time the indicator is complete. To create a determinate progress indicator, use a non-null value between 0.0 and 1.0.
• Indeterminate. Indeterminate progress indicators do not have a specific value at each point in time and instead indicate that progress is being made without indicating how much progress remains. To create an indeterminate progress indicator, use a null value.

The indicator line is displayed with valueColor, an animated value. To specify a constant color value use: AlwaysStoppedAnimation<Color>(color).

The minimum height of the indicator can be specified using minHeight. The indicator can be made taller by wrapping the widget with a SizedBox.

This example showcases determinate and indeterminate LinearProgressIndicators. The LinearProgressIndicators will use the when setting the LinearProgressIndicator.year2023 flag to false.

link

To create a local project with this code sample, run:
flutter create --sample=material.LinearProgressIndicator.1 mysample

See also:

• CircularProgressIndicator, which shows progress along a circular arc.
• RefreshIndicator, which automatically displays a CircularProgressIndicator when the underlying vertical scrollable is overscrolled.
• material.io/design/components/progress-indicators.html#linear-progress-indicators