Xamarin iOS应用包体积过大求助：已启用优化仍未达标，架构配置存疑

Hey there, I’ve been in your shoes wrestling with Xamarin iOS app size issues, so let’s break down how to tackle this beyond the basic optimization settings you’ve already tried.

First: Address the Dual Architecture (ARMv7 + ARM64) Issue #

You noticed enabling both architectures generates two app binaries—this is exactly why your App Store submission shows such a large size (it’s a "fat binary" containing code for both architectures). Here’s what to do:

• Drop ARMv7 if possible: iOS 11 and later no longer support ARMv7 devices (that’s iPhone 5 and older). If your user base doesn’t include these ancient devices, switch your Supported Architectures to only ARM64. This will immediately cut your binary size roughly in half—your 86MB fat package could drop to ~43MB right there.
• If you must support ARMv7: Remember that App Store’s App Thinning will still serve only the relevant architecture to users, so their actual download size will be smaller. But your submitted package will still be the fat size, so this only helps end users, not your submission size.

Additional Optimization Steps to Shrink Your Package #

Even after fixing the architecture, here are more tweaks to squeeze out extra bytes:

1. Crank Up the Linker (Carefully) #

You’ve enabled the Linker, but try switching from Link Framework SDKs Only to Link All Assemblies. This will strip unused code from all assemblies (including your own and NuGet packages). Just be aware:

• You might hit runtime errors if the linker removes code that’s only used via reflection. Fix this by adding the [Preserve] attribute to classes/methods that need to stay, or use a linker.xml file to explicitly preserve assemblies/types.

2. Purge Unused Resources #

• Compress images: Use tools like TinyPNG to shrink PNG/JPG assets without losing quality. For vector assets (PDF/SVG), ensure they’re properly optimized.
• Delete unused files: Go through your project and remove any images, audio, or other resources that aren’t actually referenced in your code. Xamarin can sometimes bundle files that are in the project but never used.
• Trim localization: If your app doesn’t need to support 20+ languages, delete the .lproj folders for locales you don’t use.

3. Audit NuGet Packages #

Some NuGet packages bring along bulky dependencies or unused resources. Ask yourself:

• Do you really need that full-featured package? Could you replace it with a lighter alternative?
• Check if any packages include large static libraries or embedded resources you don’t use—you might be able to manually exclude them from your build.

4. Enable Bitcode (If Compatible) #

Bitcode allows Apple to recompile your app on their servers with additional optimizations. To enable it:

• In your iOS project settings, set Enable Bitcode to Yes. Note that some third-party libraries might not support Bitcode, so test thoroughly after enabling.

5. Analyze Your Package to Find Bloat #

Use Xcode’s built-in tools to see exactly what’s taking up space:

• After building your release package, open it in Xcode and go to Window > Organizer > Archives. Select your archive, click Distribute App, and choose Development—this will generate an App Thinning Size Report that breaks down your package size by component (binaries, resources, etc.).
• Target the biggest offenders first—if a single static library is taking 20MB, you know where to focus.

6. Ensure You’re Building for Release Only #

Double-check that you’re not accidentally including debug artifacts:

• Build using the Release configuration, not Debug.
• Disable Embed Debug Symbols in your release settings (you can still upload symbols separately to Apple if needed for crash reporting).

内容的提问来源于stack exchange，提问作者Oleg Kosuakiv