PCH files in IOS development, and what is commonly used by PCH

First, create the PCH file. Click Command+n. such as Operation

Naming conventions are generally: project name-prefix

Step Two

OK, you have finished making the PCH file here. Then you can use it.

PCH files generally write data that can be used globally.

Like what:

The width and color of the screen (no punctuation behind the macro)

#define RGB (r,g,b,a)   [Uicolor colorwithred: (r/255.0) Green: (g/255.0) Blue: (b/255.0) Alpha: (a)] #define SCREEN_W [ UIScreen mainscreen].bounds.size.width#define Screen_h [UIScreen mainscreen].bounds.size.height

Of course, there are more lines of macros. Multi-line macros are written with backslashes at the end of each line.

#define DLSTOREUSERID (name, key) nsuserdefaults *defaults = [Nsuserdefaults standarduserdefaults]; [Defaults setobject: (NSString *) name Forkey: (NSString *) key]; [Defaults synchronize]\

PCH files in IOS development, and what is commonly used by PCH