Xamarin Ios Migration

Xamarin.iOS / Xamarin.Mac / Xamarin.tvOS → .NET Migration

For SDK-style project templates, MSBuild property tables, RuntimeIdentifier conversion tables, and namespace mappings, see references/ios-migration-api.md.

Migration Workflow

1. Create new .NET for iOS/macOS/tvOS project (same name, copy code into it)
2. Update MSBuild properties (see references/ios-migration-api.md)
3. Move MinimumOSVersion from Info.plist → SupportedOSPlatformVersion in csproj
4. Copy code, resources, storyboards, entitlements
5. Update NuGet dependencies
6. Migrate binding libraries (if applicable)
7. Replace Xamarin.Essentials with true
8. Remove .dll.config files (not supported in .NET)
9. Delete bin//obj/, build, verify code signing, test on device

> Strategy: Create a new project and copy code into it — don't edit the existing project file.

Critical Gotchas

⚠️ No Backward Compatibility for iOS/Mac NuGet Packages

Unlike Android, there is no backward compatibility with old Xamarin iOS/Mac TFMs. Packages targeting monotouch, xamarinios, xamarinios10, monomac, or xamarinmac will not work — they must be recompiled for net8.0-ios etc.

⚠️ CodeSigningKey → CodesignKey Rename

Apple Distribution: My Company

Apple Distribution: My Company

Also rename MtouchEnableSGenConc → EnableSGenConc.

⚠️ No .dll.config or .exe.config Support

.dll.config and ` are not supported in .NET Core. Migrate configuration to appsettings.json`, embedded resources, or platform preferences.

⚠️ watchOS Is Not Supported

Xamarin.watchOS has no .NET equivalent. Bundle Swift extensions with .NET for iOS apps instead.

⚠️ OpenGL (iOS) Is Not Supported

OpenTK is unavailable in .NET for iOS. Migrate to Metal or SceneKit.

⚠️ Linker Behavior Is Stricter

Update LinkDescription XML files if custom linker configuration was used. The linker in .NET is stricter and may trim symbols that the Xamarin linker preserved.

Platform-Specific Pitfalls

| Pitfall | Impact | Mitigation | |---------|--------|------------| | iOS/Mac NuGet packages not backward-compatible | Build failures for packages targeting xamarinios | Recompile or find .NET-compatible alternatives | | CodeSigningKey silently ignored | App fails to sign but no clear error | Rename to CodesignKey | | MtouchArch not converted | Wrong architecture targeted | Convert to RuntimeIdentifier(s) — see reference tables | | MinimumOSVersion left in Info.plist | Ignored — uses csproj value | Move to SupportedOSPlatformVersion | | Entitlements path wrong | Build succeeds but runtime failures | Verify CodesignEntitlements points to correct file | | .dll.config files present | Silently ignored at runtime | Remove and migrate to alternatives |

Binding Library Migration Tips

• Use SDK-style project format with net8.0-ios TFM
• The binding generator and API definitions work the same way
• Verify native frameworks are updated for the target iOS version
• Test thoroughly — binding edge cases are common in .NET migrations

NuGet Compatibility Decision

| Situation | Action | |-----------|--------| | You own the package | Recompile with .NET TFMs | | Package has preview .NET version | Use preview | | No compatible version | Replace with .NET-compatible alternative | | .NET Standard library (no platform deps) | ✅ Still works |

Build Troubleshooting

| Issue | Fix | |-------|-----| | Namespace not found | Most UIKit namespaces are unchanged — verify against .NET for iOS API surface | | Linker errors | Update LinkDescription XML files — linker is stricter in .NET | | Code signing failure | Verify CodesignKey, CodesignProvision, CodesignEntitlements | | Entitlements mismatch | Ensure entitlements file matches provisioning profile |

API Currency Warning

If your migrated app will also adopt .NET MAUI controls (e.g., via UseMaui), check the maui-current-apis skill for deprecated MAUI APIs to avoid (ListView, Frame, Device.*, etc.).

Quick Checklist

1. ☐ Created new .NET for iOS/macOS/tvOS project
2. ☐ Set TargetFramework to net8.0-ios (or -macos/-tvos)
3. ☐ Moved MinimumOSVersion → SupportedOSPlatformVersion in csproj
4. ☐ Converted MtouchArch → RuntimeIdentifier(s)
5. ☐ Converted HttpClientHandler → UseNativeHttpHandler
6. ☐ Renamed CodeSigningKey → CodesignKey
7. ☐ Renamed MtouchEnableSGenConc → EnableSGenConc
8. ☐ Copied source, resources, storyboards, entitlements
9. ☐ Updated NuGet dependencies (no backward compat with Xamarin TFMs!)
10. ☐ Added UseMauiEssentials + Platform.Init() if using Essentials
11. ☐ Removed .dll.config files
12. ☐ Deleted bin/ and obj/ folders
13. ☐ Verified code signing and provisioning
14. ☐ Tested on physical device

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: davidortinau
• Source: davidortinau/maui-skills
• License: MIT

Install and usage instructions live in the source repository linked above.