To add a global PCH file to a project

Note that this blog post is only convenient for later in the Add PCH file configuration when the reference to use, worried about some of the configuration of the path due to time and forgotten.

(1) Build a PCH file

Note that the following should be Targets after the

(2) Some configuration of the file

Select the project project file, as shown in the following:

(3) Handling of common errors

Most of the introduction of the path, write exactly as above, but after compiling or will error, this time again to open the path we wrote, we will find that the path is a duplicate reference, when the duplicate references are deleted, again compile on OK.

In addition, if it is a system file, we introduced in the PCH file, note to use <> can not use "", if it is the class we write, when we introduce, do not use <> to use "", such as the correct introduction of the Foundation framework, the correct wording is #im Port<foundation/foundation.h> error: #import "Foundation/foundation.h" or #import "Foundation.h"

To add a global PCH file to a project