Android Programming: The Big Nerd Ranch Guide, 2nd Edition

Hosting a UI Fragment

To host a UI fragment, an activity must:

• define a spot in its layout for the fragment’s view

• manage the lifecycle of the fragment instance

The fragment lifecycle

Figure 7.12 shows the fragment lifecycle. It is similar to the activity lifecycle: it has stopped, paused, and running states, and it has methods you can override to get things done at critical points – many of which correspond to activity lifecycle methods.

Figure 7.12  Fragment lifecycle diagram

The correspondence is important. Because a fragment works on behalf of an activity, its state should reflect the activity’s state. ...