Question

Is it possible to have activity without UI to perform action?A. not possible B.wrong question C.Yes,it is possible D,none

Answer 1

Answer: C. Yes, it is possible.

Explanation and notes:
- An Activity can have no visible UI (for example by not calling setContentView or by using the Theme.NoDisplay theme). This is useful for doing a quick task that needs an Activity context (e.g., handle an intent, request permissions, show a transient dialog) and then finish().
- Typical pattern: use android:theme="@android:style/Theme.NoDisplay" in the manifest for that activity, perform work in onCreate/onResume, then call finish().

Example (Java):
```java
public class NoUiActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// perform action here
doWork();
finish();
}
}
```
Manifest:
```xml
<activity android:name=".NoUiActivity"
android:theme="@android:style/Theme.NoDisplay" />
```

Recommendation: for background or long-running tasks, prefer Service, WorkManager, or JobScheduler instead of an Activity.