Xcode IDE
Xcode: symbol(s) not found for architecture armv7
log : Undefined symbols for architecture armv7:”OBJC_CLASS$_ViewController”, referenced from:objc-class-ref in AppDelegate.o
ld: symbol(s) not found for architecture armv7
clang: error: linker command failed with exit code 1 (use -v to see invocation)
Check if your Compile Sources section within the Build Phases of your project shows ViewController.m
参考: http://stackoverflow.com/questions/12522571/xcode-symbols-not-found-for-architecture-armv7
How to trap on UIViewAlertForUnsatisfiableConstraints?
I added UIViewAlertForUnsatisfiableConstraints symbolic breakpoint with suggested action: Obj-C project
po [[UIWindow keyWindow] _autolayoutTrace]
Swift project
expr -l objc++ -O – [[UIWindow keyWindow] _autolayoutTrace]
参考：http://stackoverflow.com/questions/26389273/how-to-trap-on-uiviewalertforunsatisfiableconstraints
How to define Preprocessor Macros in Xcode
- Find TARGETS -> Build Settings , search Preprocessor Macros , By default we have tow:Debug and Release, Notice that the Dubug configuration already has a Macro defined - it’s called DEBUG=1. therefore out of the box you can already check in your code if it has been complied with the Debug or Release configuration.
- To define your own Macro, click the little plus sign next Debug (and Release) and add something specific. I’m using IS_PRO=1, but you can choose anything you like really. I don’t know if you can set values other than boolean. Make sure you set your Macro in BOTH configurations, otherwise you’ll find different results when you submit your app
- Now that our Macro is defined, you can check if it’s present in your code like so:
#ifdef IS_PRO
NSLog(@"It's the PRO version");
#else
NSLog(@"Must be the LITE version");
#endif
2017-04-20 高飞
