關於 undefined symbols for architecture armv7 referenced from 問題

今天在調用公司其它人寫的靜態庫的時候，編譯一直沒法經過一直報錯 undefined symbols for architecture armv7 referenced from。

最後發現是在製做靜態庫的時候，只是把文件添加到了工程。

可是compil sources裏面默認沒有添加的，須要咱們手動去添加資源文件，而後就解決了。

 

 

下面附帶stackoverflow有人分析的幾個緣由

http://stackoverflow.com/questions/6429494/undefined-symbols-for-architecture-armv7

The common causes for "Undefined symbols for architecture armv7" are:

1. You import a header and do not link against the correct library. This is common, especially for headers for libraries like QuartzCore since it is not included in projects by default. To resolve:

   • Add the correct libraries in the Link Binary With Libraries section of the Build Phases.

   • If you want to add a library outside of the default search path you can include the path in theLibrary Search Paths value in the Build Settings and add 
     -l{library_name_without_lib_and_suffix} (eg. for libz.a use -lz) to the Other Linker Flags section of Build Settings.
     
     

2. You copy files into your project but forgot to check the target to add the files to. To resolve:

   • Open the Build Phases for the correct target, expand Compile Sources and add the missing .m files. If this is your issue please upvote Cortex's answer below as well.
     
     

3. You include a static library that is built for another architecture like i386, the simulator on your host machine. To resolve:

   • If you have multiple library files from your libraries vendor to include in the project you need to include the one for the simulator (i386) and the one for the device (armv7 for example).

   • Optionally, you could create a fat static library that contains both architectures.