Passing data to destination in iOS Swift - UI Render Trace

Component - Passing data to destination

This UI component shows how to send data from one screen to another in an iOS app using Swift. When you tap a button, it moves to a new screen and shows the passed message.

Widget Tree

NavigationView
└── VStack
    ├── Text ("First Screen")
    └── NavigationLink
        └── Text ("Go to Second Screen")

SecondView (receives message)

The main screen uses a NavigationView with a vertical stack. It shows a title text and a button (NavigationLink). When the button is tapped, it navigates to SecondView, which displays the passed message.

Render Trace - 5 Steps

Step 1: NavigationView

Step 2: VStack

Step 3: Text ("First Screen")

Step 4: NavigationLink

Step 5: SecondView

State Change - Re-render

Trigger:User taps 'Go to Second Screen' button

Before

Showing First Screen with button

→

After

Showing Second Screen with message 'Hello from First Screen'

Re-renders:Entire screen changes from FirstView to SecondView

UI Quiz - 3 Questions

What happens when the user taps the 'Go to Second Screen' button?

A The app stays on the same screen and changes the button text.

B The app closes.

C The app navigates to SecondView and shows the passed message.

D The app shows an alert but does not navigate.

Key Insight

Passing data between screens in iOS SwiftUI is simple and clear by using NavigationLink with destination views that accept data as parameters. This keeps data flow easy to follow and UI responsive.