The app bar, also known as the action bar, is one of the most important design
elements in your app's activities, because it provides a visual structure and interactive elements
that are familiar to users. Using the app bar makes your app consistent with other Android apps,
letting users quickly understand how to operate your app and have a great experience.
The key functions of the app bar are as follows:
Dedicated space for giving your app an identity and indicating the user's location in the
Predictable access to important actions, such as search.
Support for navigation and view switching, using tabs or menus.
This documentation section describes how to use the AndroidX
Toolbar widget as an
app bar. There are other ways to implement an app bar—for example, some themes set up an
ActionBar as an app bar by
default—but using the AppCompat Toolbar makes it easier to set up an app bar that
works on the widest range of devices. It also gives you room to customize your app bar later in your