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Fluttermobile~10 mins

Radio buttons in Flutter - UI Render Trace

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Component - Radio buttons

This UI component shows a group of radio buttons. Users can select only one option at a time. It is useful for choosing one item from a small list.

Widget Tree
Scaffold
├─ AppBar
│  └─ Text
└─ Column
   ├─ ListTile
   │  ├─ Radio
   │  └─ Text
   ├─ ListTile
   │  ├─ Radio
   │  └─ Text
   └─ ListTile
      ├─ Radio
      └─ Text
The Scaffold provides the basic screen structure with an AppBar at the top showing a title. The body is a Column that stacks three ListTiles vertically. Each ListTile contains a Radio button and a Text label next to it.
Render Trace - 5 Steps
Step 1: Scaffold
Step 2: Column
Step 3: ListTile (first)
Step 4: ListTile (second)
Step 5: ListTile (third)
State Change - Re-render
Trigger:User taps on a radio button
Before
selected option is 1
After
selected option changes to tapped radio button's value (e.g., 2)
Re-renders:Entire StatefulWidget subtree containing the Column and ListTiles re-renders to update radio button selection
UI Quiz - 3 Questions
Test your understanding
What happens when you tap a radio button in this UI?
ANothing changes visually
BAll radio buttons become selected
CThe tapped radio button becomes selected and others deselect
DThe app crashes
Key Insight
Radio buttons let users pick one choice from a small set. Grouping them with the same groupValue ensures only one can be selected at a time. Using ListTile with Radio and Text creates a clean, accessible row for each option.