Hey there, let's break down your three questions one by one and give you practical, actionable solutions:

1. 如何为最新Xcode版本修改现有Podfile？ #

Updating your Podfile for the latest Xcode boils down to a few key adjustments to ensure compatibility with modern SDKs, compilers, and Apple's guidelines:

• Raise your iOS deployment target: The latest Xcode versions drop support for older iOS versions (e.g., iOS 12 is a common minimum these days). Update the platform :ios line to match Xcode's supported minimum, like platform :ios, '12.0'.
• Use modern framework/module settings: Add use_frameworks! (for Swift or mixed Swift/Obj-C projects) or use_modular_headers! (for pure Obj-C projects) inside your target block. This ensures pods integrate correctly with Xcode's new build system.
• Update outdated pods: Old pods (like your AFNetworking 1.2.0) often don't support new compiler features or deprecated SDKs. Check each pod's GitHub repo for the latest compatible version and update your Podfile entries.
• Refresh your pod setup: Run pod repo update to fetch the latest pod specs, then pod install --repo-update to reinstall pods with the new configuration.
• Align Xcode build settings: Make sure your project's Deployment Target in Xcode matches the one in your Podfile, and double-check Swift version (if using Swift pods) to avoid version mismatches.

2. 格式化Podfile并解决AFNetworking构建错误 #

First, here's a cleaned-up, modernized version of your Podfile tailored for the latest Xcode:

platform :ios, '12.0'
target 'PushChatStarter' do
  use_frameworks!

  # Replaced outdated AFNetworking 1.2.0 with a modern, compatible version
  pod 'AFNetworking', '~> 4.0'
  
  pod 'MBProgressHUD', '~> 1.2' # Updated to latest stable version for better compatibility
  pod 'MessageBanner', '~> 1.0'
  pod 'Alamofire', '~> 5.8' # Updated to match modern iOS/Xcode
  pod 'AlamofireImage', '~> 4.2' # Matches Alamofire 5.x
  pod 'Stripe', '~> 23.0' # Specified stable version instead of floating
  pod 'Cards'
end

Why you're seeing AFNetworking build errors: #

Your original AFNetworking 1.2.0 is extremely outdated (released in 2013). It relies on NSURLConnection, which was deprecated in iOS 9, and doesn't support the latest LLVM compiler features or SDK changes in modern Xcode. This leads to missing symbols, syntax errors, and compatibility breaks.

Fixes: #

• Preferred solution: Upgrade AFNetworking to version 4.x or 5.x. These versions use NSURLSession (the modern networking API), support ARC fully, and are maintained to work with the latest Xcode and iOS versions. You'll need to update any code that uses AFNetworking's old APIs (check their migration guide for details).
• If you must keep AFNetworking 1.2.0:
  1. Add modular header exceptions for it in your Podfile:

     pod 'AFNetworking', '~> 1.2.0' do
       pod 'AFNetworking', :modular_headers => false
     end
     

  2. In Xcode, select the AFNetworking target, go to Build Settings, set its Deployment Target to iOS 6.0, and ensure Objective-C Automatic Reference Counting is enabled.
  3. Note: This is a temporary workaround—old pods have security vulnerabilities and will stop working completely in future Xcode versions.

3. 安装新gems后AFNetworking运行失败的原因 #

Installing new gems likely altered your Ruby/CocoaPods environment, which caused the breakage. Here are the most common culprits:

• CocoaPods version update: New gems might have upgraded CocoaPods to the latest version, which drops support for very old pods like AFNetworking 1.2.0. The new CocoaPods build system handles dependencies and headers differently, leading to compilation errors.
• Ruby environment changes: New gems could have modified your Ruby version or gem dependencies, causing CocoaPods to behave unexpectedly during pod installation (e.g., incorrect dependency resolution).
• Cache corruption: Updating gems can invalidate your existing pod cache, leading to incomplete or misconfigured pod installations when you run pod install.
• Toolchain path changes: In rare cases, new gems might affect how CocoaPods calls Xcode tools, leading to SDK version mismatches that break old pods.

How to fix it: #

• Clean and reinstall pods: Run pod deintegrate to remove all existing pod integration, then pod cache clean --all to clear cached pods, and finally pod install to start fresh.
• Downgrade CocoaPods: If the latest CocoaPods version is the issue, install an older, compatible version with sudo gem install cocoapods -v 1.8.4 (this version works well with older pods), then run pod install using this version.
• Upgrade AFNetworking: As mentioned earlier, this is the most sustainable fix—modern pods are designed to work with the latest CocoaPods and Xcode versions.

内容的提问来源于stack exchange，提问作者Aaron Navies