代码规范网址：http://www.csdn.net/article/2015-06-01/2824818-objective-c-style-guide
https://github.com/VincentSit/NYTimes-Objective-C-Style-Guide-ZH
1、方法的行数不能大于150，controller的文件代码行数不能大于800
2、#pragma mark 注释
控制器的注释
#pragma mark - --- lift cycle 生命周期 ---
#pragma mark - --- delegate 视图委托 ---
#pragma mark - --- event response 事件相应 ---
#pragma mark - --- private methods 私有方法 ---
#pragma mark - --- getters and setters 属性 ---
视图的注释
#pragma mark - --- init 视图初始化 ---
#pragma mark - --- delegate 视图委托 ---
#pragma mark - --- event response 事件相应 ---
#pragma mark - --- private methods 私有方法 ---
#pragma mark - --- setters 属性 ---
#pragma mark - --- getters 属性 —
3、属性注释的代码段
@property(nullable, nonatomic, readonly)<#Class#> *<#obj#> ; // <##>
@property(nullable, nonatomic, readwrite)<#Class#> *<#obj#> ; // <##>
@property(nullable, nonatomic, strong)<#Class#> *<#obj#> ; // <##>
@property(nullable, nonatomic, copy)<#Class#> *<#obj#> ; // <##>
@property(nullable, nonatomic, weak)<#Class#> *<#obj#> ; // <##>
@property(readonly, getter=is<#obj#>)BOOL <#obj#> ; // <##>
@property(null_resettable, nonatomic, strong)<#Class#> *<#obj#> ; // <##>
@property(nonatomic)<#Class#> <#obj#> ; // <##>
@property(nonatomic, assign)<#Class#> <#obj#> ; // <##>