一些宏

dealloc里面释放对象

#if DEBUG  
#define MCRelease(x) [x release]  
#else  
#define MCRelease(x) [x release], x = nil  
#endif 

//use dlog to print while in debug model
#ifdef DEBUG
#   define DLog(fmt, ...) NSLog((@"%s [Line %d] " fmt), __PRETTY_FUNCTION__, __LINE__, ##__VA_ARGS__);
#else
#   define DLog(...)
#endif

在不同系统区分代码

#ifdef __IPHONE_5_0
    float version = [[[UIDevice currentDevice] systemVersion] floatValue];
    if (version >= 5.0) {
        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShow:) name:UIKeyboardWillChangeFrameNotification object:nil];
    }
#endif

系统信息

#define NavigationBar_HEIGHT 44
 
#define SCREEN_WIDTH ([UIScreen mainScreen].bounds.size.width)
#define SCREEN_HEIGHT ([UIScreen mainScreen].bounds.size.height)
#define SAFE_RELEASE(x) [x release];x=nil
#define IOS_VERSION [[[UIDevice currentDevice] systemVersion] floatValue]
#define CurrentSystemVersion ([[UIDevice currentDevice] systemVersion])  
#define CurrentLanguage ([[NSLocale preferredLanguages] objectAtIndex:0]) 

设备

#define isRetina ([UIScreen instancesRespondToSelector:@selector(currentMode)] ? CGSizeEqualToSize(CGSizeMake(640, 960), [[UIScreen mainScreen] currentMode].size) : NO)
#define iPhone5 ([UIScreen instancesRespondToSelector:@selector(currentMode)] ? CGSizeEqualToSize(CGSizeMake(640, 1136), [[UIScreen mainScreen] currentMode].size) : NO)
#define isPad (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad)
 
 
#if TARGET_OS_IPHONE
//iPhone Device
#endif
 
#if TARGET_IPHONE_SIMULATOR
//iPhone Simulator
#endif

RGB颜色

#define RGBCOLOR(r,g,b) [UIColor colorWithRed:(r)/255.0f green:(g)/255.0f blue:(b)/255.0f alpha:1]
#define RGBACOLOR(r,g,b,a) [UIColor colorWithRed:(r)/255.0f green:(g)/255.0f blue:(b)/255.0f alpha:(a)]
#define BACKGROUND_COLOR [UIColor colorWithRed:242.0/255.0 green:236.0/255.0 blue:231.0/255.0 alpha:1.0]

ARC监测

//ARC
#if __has_feature(objc_arc)
    //compiling with ARC
#else
    // compiling without ARC
#endif

度,弧度

#pragma mark - degrees/radian functions 
#define degreesToRadian(x) (M_PI * (x) / 180.0)
#define radianToDegrees(radian) (radian*180.0)/(M_PI)

RGB颜色转换（16进制->10进制）

#define UIColorFromRGB(rgbValue)  [UIColor colorWithRed:((float)((rgbValue & 0xFF0000) >> 16))/255.0 green:((float)((rgbValue & 0xFF00) >> 8))/255.0 blue:((float)(rgbValue & 0xFF))/255.0 alpha:1.0]

定义CGRECT

#define CGRectMake(a,b,c,d)  CGRectMake((a)/320.0*[[UIScreen mainScreen] applicationFrame].size.width,(b)/460.0*[[UIScreen mainScreen] applicationFrame].size.height,(c)/320.0*[[UIScreen mainScreen] applicationFrame].size.width,(d)/460.0*[[UIScreen mainScreen] applicationFrame].siz

weak,strong

#define WEAKSELF typeof(self) __weak weakSelf = self;
#define STRONGSELF typeof(weakSelf) __strong strongSelf = weakSelf; 

//6.0一下兼容6.0枚举类型，避免版本导致的警告
#define UILineBreakMode                 NSLineBreakMode
#define UILineBreakModeWordWrap            NSLineBreakByWordWrapping
#define UILineBreakModeCharacterWrap    NSLineBreakByCharWrapping
#define UILineBreakModeClip                NSLineBreakByClipping
#define UILineBreakModeHeadTruncation    NSLineBreakByTruncatingHead
#define UILineBreakModeTailTruncation    NSLineBreakByTruncatingTail
#define UILineBreakModeMiddleTruncation    NSLineBreakByTruncatingMiddle

#define UITextAlignment                 NSTextAlignment
#define UITextAlignmentLeft                NSTextAlignmentLeft
#define UITextAlignmentCenter            NSTextAlignmentCenter
#define UITextAlignmentRight            NSTextAlignmentRight

 版本兼容

#define SYSTEM_VERSION_EQUAL_TO(v) ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] == NSOrderedSame)
#define SYSTEM_VERSION_GREATER_THAN(v) ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] == NSOrderedDescending)
#define SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(v) ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] != NSOrderedAscending)
#define SYSTEM_VERSION_LESS_THAN(v) ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] == NSOrderedAscending)
#define SYSTEM_VERSION_LESS_THAN_OR_EQUAL_TO(v) ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] != NSOrderedDescending)