Road is divided into absolute path and relative path I suggest more use of relative path, so that the project will worry a lot of the absolute path to find a way: Click the project a file, right-click on the "Show in Finder" to open the terminal, CD folder dragged into, you can appear a road strength, This is the path to the absolute path relative to the current project file, "./" means the current project folder, followed by all the real folder names, the project internal group is invalid, ". /"represents the upper directory, in Xcode" $ (Project_dir) "also indicates the current project folder directory needs to understand the two parameter meaning: non-recursive non-recursive lookup recursive recursive lookup xxx/** non-recursive Also means that recursive lookup, will be automatically converted to the xxx recursive example, Hello project folder under the Lib folder exists helloLib.h for Hello add helloLib.h header file search path default is non-recursive1/users/ Xxxx/desktop/hello/lib2./lib3. /hello/lib4./recursive5./** non-recursive6$ (project_dir)/lib7$ (project_dir)/** recursive with so many examples, you should be able to blend in, The header file search path must be assigned to that level, but the general works by default are found recursively from the current project folder, only when you add a third-party library, or when you make a static library.
iOS header file Search path tutorial
