Activity results in Android Kotlin - UI Render Trace

Component - Activity results

This UI component demonstrates how one Android activity starts another and receives a result back. It shows a button that opens a second screen, and when the user finishes there, the first screen displays the returned message.

Widget Tree

ActivityResultActivity
├── ConstraintLayout
│   ├── Button (Start Second Activity)
│   └── TextView (Result Display)

The root is the ActivityResultActivity which uses a ConstraintLayout as the main container. Inside it, there is a Button that the user taps to open the second activity. Below the button, a TextView shows the result returned from the second activity.

Render Trace - 5 Steps

Step 1: ActivityResultActivity

Step 2: Button (Start Second Activity)

Step 3: SecondActivity

Step 4: SecondActivity Submit Button

Step 5: ActivityResultActivity

State Change - Re-render

Trigger:User taps the button to start second activity and submits a result

Before

TextView is empty, no result shown

→

After

TextView shows the returned message from second activity

Re-renders:The TextView displaying the result is updated and re-rendered

UI Quiz - 3 Questions

What happens when the user taps the 'Start Second Activity' button?

A The app closes immediately

B The app opens the second activity expecting a result

C The text in TextView changes to 'Hello'

D Nothing happens

Key Insight

Using activity results allows one screen to get information back from another screen, enabling smooth user flows like forms or selections. The UI updates only the part showing the result, keeping the app responsive and clear.