iOS總結了幾個月的東西和大家分享一下

1、禁止手機睡眠

[UIApplication sharedApplication].idleTimerDisabled = YES;

2、隱藏某行cell

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath

{

// 如果是你需要隱藏的那一行，返回高度為0

if(indexPath.row == YouWantToHideRow)

return 0;

return 44;

}

// 然后再你需要隱藏cell的時候調用

[self.tableView beginUpdates];

[self.tableView endUpdates];

3、禁用button高亮

button.adjustsImageWhenHighlighted = NO;

或者在創建的時候

UIButton?*button?=?[UIButton?buttonWithType:UIButtonTypeCustom];

4、tableview遇到這種報錯failed to obtain a cell from its dataSource

是因為你的cell被調用的早了。先循環使用了cell，后又創建cell。順序錯了

可能原因：1、xib的cell沒有注冊 2、內存中已經有這個cell的緩存了(也就是說通過你的cellId找到的cell并不是你想要的類型)，這時候需要改下cell的標識

5、cocoa pods報這個錯誤：unable to access ‘https://github.com/facebook/pop.git/': Operation timed out after 0 milliseconds with 0 out of 0 bytes received

解決辦法：原因可能是網絡問題，網絡請求超時了，只需要重試就行了

6、cocoa pods 出現ERROR: While executing gem ... (Errno::EPERM)

解決辦法：

https://segmentfault.com/q/1010000002926243

7、動畫切換window的根控制器

// options是動畫選項

[UIView?transitionWithView:[UIApplication?sharedApplication].keyWindow?duration:0.5f?options:UIViewAnimationOptionTransitionCrossDissolve?animations:^{

BOOL?oldState?=?[UIView?areAnimationsEnabled];

[UIView?setAnimationsEnabled:NO];

[UIApplication?sharedApplication].keyWindow.rootViewController?=?[RootViewController?new];

[UIView?setAnimationsEnabled:oldState];

}?completion:^(BOOL?finished)?{

}];

8、去除數組中重復的對象

NSArray *newArr = [oldArr valueForKeyPath:@“@distinctUnionOfObjects.self"];

9、編譯的時候遇到 no such file or directory: ／users／apple／XXX

是因為編譯的時候，在此路徑下找不到這個文件，解決這個問題，首先是是要檢查缺少的文件是不是在工程中，如果不在工程中，需要從本地拖進去，如果發現已經存在工程中了，或者拖進去還是報錯，這時候需要去build phases中搜索這個文件，這時候很可能會搜出現兩個相同的文件，這時候，有一個路徑是正確的，刪除另外一個即可。如果刪除了還是不行，需要把兩個都刪掉，然后重新往工程里拖進這個文件即可

10、iOS8系統中，tableView最好實現下-tableView: heightForRowAtIndexPath:這個代理方法，要不然在iOS8中可能就會出現顯示不全或者無法響應事件的問題

11、iOS8中實現側滑功能的時候這個方法必須實現，要不然在iOS8中無法側滑

// 必須寫的方法，和editActionsForRowAtIndexPath配對使用，里面什么不寫也行

-?(void)tableView:(UITableView?*)tableView?commitEditingStyle:(UITableViewCellEditingStyle)editingStyle?forRowAtIndexPath:(NSIndexPath?*)indexPath?{

}

12、三個通知

NSSystemTimeZoneDidChangeNotification監聽修改時間界面的兩個按鈕狀態變化

UIApplicationSignificantTimeChangeNotification 監聽用戶改變時間 （只要點擊自動設置按鈕就會調用） NSSystemClockDidChangeNotification 監聽用戶修改時間（時間不同才會調用）

13、SDWebImage本地緩存有時候會害人。如果之前緩存過一張圖片，即使下次服務器換了這張圖片，但是圖片url沒換，用sdwebimage下載下來的還是以前那張,所以遇到這種問題，不要先去懟服務器，清空下緩存再試就好了。

14、上線前注意：

1、刪掉代碼中所有的測試代碼

2、如果后臺有審核模式，提醒后臺開啟此模式

3、主流程再跑一跑

4、全局搜索waring，檢查所有標記waring的地方

15、跳進app權限設置

// 跳進app設置

if (UIApplicationOpenSettingsURLString != NULL) {

NSURL *url = [NSURL URLWithString:UIApplicationOpenSettingsURLString];

[[UIApplication sharedApplication] openURL:url];

}

}

16、給一個view截圖

UIGraphicsBeginImageContextWithOptions(view.bounds.size, YES, 0.0);

[view.layer renderInContext:UIGraphicsGetCurrentContext()];

UIImage *img = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

17、開發中如果要動態修改tableView的tableHeaderView或者tableFooterView的高度，需要給tableView重新設置，而不是直接更改高度。正確的做法是重新設置一下tableView.tableFooterView = 更改過高度的view。為什么？其實在iOS8以上直接改高度是沒有問題的，在iOS8中出現了contentSize不準確的問題，這是解決辦法。

18、注意對象為nil的時候，調用此對象分類的方法不會執行

19、collectionView的內容小于其寬高的時候是不能滾動的，設置可以滾動：

collectionView.alwaysBounceHorizontal = YES;

collectionView.alwaysBounceVertical?=?YES;

20、設置navigationBar上的title顏色和大小

[self.navigationController.navigationBar setTitleTextAttributes:@{NSForegroundColorAttributeName : [UIColor youColor], NSFontAttributeName : [UIFont systemFontOfSize:15]}]

21、顏色轉圖片

+ (UIImage *)cl_imageWithColor:(UIColor *)color {

CGRect rect = CGRectMake(0.0f, 0.0f, 1.0f, 1.0f);

UIGraphicsBeginImageContext(rect.size);

CGContextRef context = UIGraphicsGetCurrentContext();

CGContextSetFillColorWithColor(context, [color CGColor]);

CGContextFillRect(context, rect);

UIImage *image = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

return image;

}

22、view設置圓角

#define ViewBorderRadius(View, Radius, Width, Color)\

\

[View.layer setCornerRadius:(Radius)];\

[View.layer setMasksToBounds:YES];\

[View.layer setBorderWidth:(Width)];\

[View.layer setBorderColor:[Color CGColor]] // view圓角

23、強／弱引用

#define WeakSelf(type)? __weak typeof(type) weak##type = type; // weak

#define StrongSelf(type)? __strong typeof(type) type = weak##type; // strong

24、由角度轉換弧度

#define DegreesToRadian(x) (M_PI * (x) / 180.0)

25、由弧度轉換角度

#define RadianToDegrees(radian) (radian*180.0)/(M_PI)

26、獲取圖片資源

#define GetImage(imageName) [UIImage imageNamed:[NSString stringWithFormat:@"%@",imageName]]

27、獲取temp

#define PathTemp NSTemporaryDirectory()

28、獲取沙盒 Document

#define PathDocument [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) firstObject]

29、獲取沙盒 Cache

#define PathCache [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) firstObject]

30、GCD代碼只執行一次

#define kDISPATCH_ONCE_BLOCK(onceBlock) static dispatch_once_t onceToken; dispatch_once(&onceToken, onceBlock);

31、自定義NSLog

#ifdef DEBUG

#define NSLog(fmt, ...) NSLog((@"%s [Line %d] " fmt), __PRETTY_FUNCTION__, __LINE__, ##__VA_ARGS__)

#else

#define NSLog(...)

#endif

32、Font

#define FontL(s)? ? ? ? ? ? [UIFont systemFontOfSize:s weight:UIFontWeightLight]

#define FontR(s)? ? ? ? ? ? [UIFont systemFontOfSize:s weight:UIFontWeightRegular]

#define FontB(s)? ? ? ? ? ? [UIFont systemFontOfSize:s weight:UIFontWeightBold]

#define FontT(s)? ? ? ? ? ? [UIFont systemFontOfSize:s weight:UIFontWeightThin]

#define Font(s)? ? ? ? ? ? ? FontL(s)

33、FORMAT

#define FORMAT(f, ...)? ? ? [NSString stringWithFormat:f, ## __VA_ARGS__]

34、在主線程上運行

#define kDISPATCH_MAIN_THREAD(mainQueueBlock) dispatch_async(dispatch_get_main_queue(), mainQueueBlock);

35、開啟異步線程

#define kDISPATCH_GLOBAL_QUEUE_DEFAULT(globalQueueBlock) dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), globalQueueBlocl);

36、通知

#define NOTIF_ADD(n, f)? ? [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(f) name:n object:nil]

#define NOTIF_POST(n, o)? ? [[NSNotificationCenter defaultCenter] postNotificationName:n object:o]

#define NOTIF_REMV()? ? ? ? [[NSNotificationCenter defaultCenter] removeObserver:self]

37、隨機顏色

+ (UIColor *)RandomColor {

NSInteger aRedValue = arc4random() % 255;

NSInteger aGreenValue = arc4random() % 255;

NSInteger aBlueValue = arc4random() % 255;

UIColor *randColor = [UIColor colorWithRed:aRedValue / 255.0f green:aGreenValue / 255.0f blue:aBlueValue / 255.0f alpha:1.0f];

return randColor;

}

38、獲取window

+(UIWindow*)getWindow {

UIWindow* win = nil; //[UIApplication sharedApplication].keyWindow;

for (id item in [UIApplication sharedApplication].windows) {

if ([item class] == [UIWindow class]) {

if (!((UIWindow*)item).hidden) {

win = item;

break;

}

}

}

return win;

}

39、修改textField的placeholder的字體顏色、大小

[textField setValue:[UIColor redColor] forKeyPath:@"_placeholderLabel.textColor"];

[textField setValue:[UIFont boldSystemFontOfSize:16] forKeyPath:@"_placeholderLabel.font"];

40、統一收起鍵盤

[[[UIApplication sharedApplication] keyWindow] endEditing:YES];

41、控制屏幕旋轉，在控制器中寫

/** 是否支持自動轉屏 */

- (BOOL)shouldAutorotate {

return YES;

}

/** 支持哪些屏幕方向 */

- (UIInterfaceOrientationMask)supportedInterfaceOrientations {

return UIInterfaceOrientationMaskLandscapeLeft | UIInterfaceOrientationMaskLandscapeRight;

}

/** 默認的屏幕方向（當前ViewController必須是通過模態出來的UIViewController（模態帶導航的無效）方式展現出來的，才會調用這個方法） */

- (UIInterfaceOrientation)preferredInterfaceOrientationForPresentation {

return UIInterfaceOrientationLandscapeLeft | UIInterfaceOrientationLandscapeRight;

}

42、獲取app緩存大小

- (CGFloat)getCachSize {

NSUInteger imageCacheSize = [[SDImageCache sharedImageCache] getSize];

//獲取自定義緩存大小

//用枚舉器遍歷 一個文件夾的內容

//1.獲取 文件夾枚舉器

NSString *myCachePath = [NSHomeDirectory() stringByAppendingPathComponent:@"Library/Caches"];

NSDirectoryEnumerator *enumerator = [[NSFileManager defaultManager] enumeratorAtPath:myCachePath];

__block NSUInteger count = 0;

//2.遍歷

for (NSString *fileName in enumerator) {

NSString *path = [myCachePath stringByAppendingPathComponent:fileName];

NSDictionary *fileDict = [[NSFileManager defaultManager] attributesOfItemAtPath:path error:nil];

count += fileDict.fileSize;//自定義所有緩存大小

}

// 得到是字節? 轉化為M

CGFloat totalSize = ((CGFloat)imageCacheSize+count)/1024/1024;

return totalSize;

}

43、清理app緩存

- (void)handleClearView {

//刪除兩部分

//1.刪除 sd 圖片緩存

//先清除內存中的圖片緩存

[[SDImageCache sharedImageCache] clearMemory];

//清除磁盤的緩存

[[SDImageCache sharedImageCache] clearDisk];

//2.刪除自己緩存

NSString *myCachePath = [NSHomeDirectory() stringByAppendingPathComponent:@"Library/Caches"];

[[NSFileManager defaultManager] removeItemAtPath:myCachePath error:nil];

}

44、模型轉字典

static NSSet *classes;

- (NSMutableDictionary *)getParameterDictionary {

NSMutableDictionary *dict = [NSMutableDictionary dictionary];

Class c = self.class;

while (c) {

unsigned count;

objc_property_t *properties = class_copyPropertyList([c class], &count);

for (int i = 0; i < count; i++) {

NSString *key = [NSString stringWithUTF8String:property_getName(properties[i])];

dict[key] = [self valueForKey:key];

}

free(properties);

// 獲得父類

c = class_getSuperclass(c);

if ([self isClassFromFoundation:c]) break;

}

return dict;

}

- (BOOL)isClassFromFoundation:(Class)c

{

if (c == [NSObject class] || c == [NSManagedObject class]) return YES;

__block BOOL result = NO;

[[self foundationClasses] enumerateObjectsUsingBlock:^(Class foundationClass, BOOL *stop) {

if ([c isSubclassOfClass:foundationClass]) {

result = YES;

*stop = YES;

}

}];

return result;

}

- (NSSet *)foundationClasses

{

if (classes == nil) {

// 集合中沒有NSObject，因為幾乎所有的類都是繼承自NSObject，具體是不是NSObject需要特殊判斷

classes = [NSSet setWithObjects:

[NSURL class],

[NSDate class],

[NSValue class],

[NSData class],

[NSError class],

[NSArray class],

[NSDictionary class],

[NSString class],

[NSAttributedString class], nil];

}

return classes;

}

45、交換兩個方法實現

Class aClass = [self class];

SEL originalSelector = @selector(viewWillAppear:);

SEL swizzledSelector = @selector(xxx_viewWillAppear:);

Method originalMethod = class_getInstanceMethod(aClass, originalSelector);

Method swizzledMethod = class_getInstanceMethod(aClass, swizzledSelector);

BOOL didAddMethod =

class_addMethod(aClass,

originalSelector,

method_getImplementation(swizzledMethod),

method_getTypeEncoding(swizzledMethod));

if (didAddMethod) {

class_replaceMethod(aClass,

swizzledSelector,

method_getImplementation(originalMethod),

method_getTypeEncoding(originalMethod));

} else {

method_exchangeImplementations(originalMethod, swizzledMethod);

}

46、打印百分號和引號

NSLog(@"%%");

NSLog(@"\"");

47、幾個常用權限判斷

if ([CLLocationManager authorizationStatus] ==kCLAuthorizationStatusDenied) {

NSLog(@"沒有定位權限");

}

AVAuthorizationStatus statusVideo = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo];

if (statusVideo == AVAuthorizationStatusDenied) {

NSLog(@"沒有攝像頭權限");

}

//是否有麥克風權限

AVAuthorizationStatus statusAudio = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeAudio];

if (statusAudio == AVAuthorizationStatusDenied) {

NSLog(@"沒有錄音權限");

}

[PHPhotoLibrary requestAuthorization:^(PHAuthorizationStatus status) {

if (status == PHAuthorizationStatusDenied) {

NSLog(@"沒有相冊權限");

}

}];

48、獲取手機型號

+ (NSString *)getDeviceInfo {

struct utsname systemInfo;

uname(&systemInfo);

NSString *platform = [NSString stringWithCString:systemInfo.machine encoding:NSASCIIStringEncoding];

if ([platform isEqualToString:@"iPhone1,1"]) return @"iPhone 2G";

if ([platform isEqualToString:@"iPhone1,2"]) return @"iPhone 3G";

if ([platform isEqualToString:@"iPhone2,1"]) return @"iPhone 3GS";

if ([platform isEqualToString:@"iPhone3,1"]) return @"iPhone 4";

if ([platform isEqualToString:@"iPhone3,2"]) return @"iPhone 4";

if ([platform isEqualToString:@"iPhone3,3"]) return @"iPhone 4";

if ([platform isEqualToString:@"iPhone4,1"]) return @"iPhone 4S";

if ([platform isEqualToString:@"iPhone5,1"]) return @"iPhone 5";

if ([platform isEqualToString:@"iPhone5,2"]) return @"iPhone 5";

if ([platform isEqualToString:@"iPhone5,3"]) return @"iPhone 5c";

if ([platform isEqualToString:@"iPhone5,4"]) return @"iPhone 5c";

if ([platform isEqualToString:@"iPhone6,1"]) return @"iPhone 5s";

if ([platform isEqualToString:@"iPhone6,2"]) return @"iPhone 5s";

if ([platform isEqualToString:@"iPhone7,1"]) return @"iPhone 6 Plus";

if ([platform isEqualToString:@"iPhone7,2"]) return @"iPhone 6";

if ([platform isEqualToString:@"iPhone8,1"]) return @"iPhone 6s";

if ([platform isEqualToString:@"iPhone8,2"]) return @"iPhone 6s Plus";

// 日行兩款手機型號均為日本獨占，可能使用索尼FeliCa支付方案而不是蘋果支付

if ([platform isEqualToString:@"iPhone9,1"])? ? return @"國行、日版、港行iPhone 7";

if ([platform isEqualToString:@"iPhone9,2"])? ? return @"港行、國行iPhone 7 Plus";

if ([platform isEqualToString:@"iPhone9,3"])? ? return @"美版、臺版iPhone 7";

if ([platform isEqualToString:@"iPhone9,4"])? ? return @"美版、臺版iPhone 7 Plus";

if ([platform isEqualToString:@"iPhone8,4"]) return @"iPhone SE";

if ([platform isEqualToString:@"iPod1,1"]) return @"iPod Touch 1G";

if ([platform isEqualToString:@"iPod2,1"]) return @"iPod Touch 2G";

if ([platform isEqualToString:@"iPod3,1"]) return @"iPod Touch 3G";

if ([platform isEqualToString:@"iPod4,1"]) return @"iPod Touch 4G";

if ([platform isEqualToString:@"iPod5,1"]) return @"iPod Touch 5G";

if ([platform isEqualToString:@"iPad1,1"]) return @"iPad 1G";

if ([platform isEqualToString:@"iPad2,1"]) return @"iPad 2";

if ([platform isEqualToString:@"iPad2,2"]) return @"iPad 2";

if ([platform isEqualToString:@"iPad2,3"]) return @"iPad 2";

if ([platform isEqualToString:@"iPad2,4"]) return @"iPad 2";

if ([platform isEqualToString:@"iPad2,5"]) return @"iPad Mini 1G";

if ([platform isEqualToString:@"iPad2,6"]) return @"iPad Mini 1G";

if ([platform isEqualToString:@"iPad2,7"]) return @"iPad Mini 1G";

if ([platform isEqualToString:@"iPad3,1"]) return @"iPad 3";

if ([platform isEqualToString:@"iPad3,2"]) return @"iPad 3";

if ([platform isEqualToString:@"iPad3,3"]) return @"iPad 3";

if ([platform isEqualToString:@"iPad3,4"]) return @"iPad 4";

if ([platform isEqualToString:@"iPad3,5"]) return @"iPad 4";

if ([platform isEqualToString:@"iPad3,6"]) return @"iPad 4";

if ([platform isEqualToString:@"iPad4,1"]) return @"iPad Air";

if ([platform isEqualToString:@"iPad4,2"]) return @"iPad Air";

if ([platform isEqualToString:@"iPad4,3"]) return @"iPad Air";

if ([platform isEqualToString:@"iPad4,4"]) return @"iPad Mini 2G";

if ([platform isEqualToString:@"iPad4,5"]) return @"iPad Mini 2G";

if ([platform isEqualToString:@"iPad4,6"]) return @"iPad Mini 2G";

if ([platform isEqualToString:@"i386"]) return @"iPhone Simulator";

if ([platform isEqualToString:@"x86_64"]) return @"iPhone Simulator";

return platform;

}

49、長按復制功能

- (void)viewDidLoad{

[self.view addGestureRecognizer:[[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(pasteBoard:)]];

}

- (void)pasteBoard:(UILongPressGestureRecognizer *)longPress {

if (longPress.state == UIGestureRecognizerStateBegan) {

UIPasteboard *pasteboard = [UIPasteboard generalPasteboard];

pasteboard.string = @"需要復制的文本";

}

}

50、cocoapods升級

在終端執行 sudo gem install -n / usr / local / bin cocoapods --pre

51、設置啟動頁后，依然顯示之前的

刪除app，手機重啟，重新安裝

52、判斷圖片類型

//通過圖片Data數據第一個字節 來獲取圖片擴展名

- (NSString *)contentTypeForImageData:(NSData *)data

{

uint8_t c;

[data getBytes:&c length:1];

switch (c)

{

case 0xFF:

return @"jpeg";

case 0x89:

return @"png";

case 0x47:

return @"gif";

case 0x49:

case 0x4D:

return @"tiff";

case 0x52:

if ([data length] < 12) {

return nil;

}

NSString *testString = [[NSString alloc] initWithData:[data subdataWithRange:NSMakeRange(0, 12)] encoding:NSASCIIStringEncoding];

if ([testString hasPrefix:@"RIFF"]

&& [testString hasSuffix:@"WEBP"])

{

return @"webp";

}

return nil;

}

return nil;

}

53、獲取手機和app信息

NSDictionary *infoDictionary = [[NSBundle mainBundle] infoDictionary];

CFShow(infoDictionary);

// app名稱

NSString *app_Name = [infoDictionary objectForKey:@"CFBundleDisplayName"];

// app版本

NSString *app_Version = [infoDictionary objectForKey:@"CFBundleShortVersionString"];

// app build版本

NSString *app_build = [infoDictionary objectForKey:@"CFBundleVersion"];

//手機序列號

NSString* identifierNumber = [[UIDevice currentDevice] uniqueIdentifier];

NSLog(@"手機序列號: %@",identifierNumber);

//手機別名： 用戶定義的名稱

NSString* userPhoneName = [[UIDevice currentDevice] name];

NSLog(@"手機別名: %@", userPhoneName);

//設備名稱

NSString* deviceName = [[UIDevice currentDevice] systemName];

NSLog(@"設備名稱: %@",deviceName );

//手機系統版本

NSString* phoneVersion = [[UIDevice currentDevice] systemVersion];

NSLog(@"手機系統版本: %@", phoneVersion);

//手機型號

NSString* phoneModel = [[UIDevice currentDevice] model];

NSLog(@"手機型號: %@",phoneModel );

//地方型號? （國際化區域名稱）

NSString* localPhoneModel = [[UIDevice currentDevice] localizedModel];

NSLog(@"國際化區域名稱: %@",localPhoneModel );

NSDictionary *infoDictionary = [[NSBundle mainBundle] infoDictionary];

// 當前應用名稱

NSString *appCurName = [infoDictionary objectForKey:@"CFBundleDisplayName"];

NSLog(@"當前應用名稱：%@",appCurName);

// 當前應用軟件版本? 比如：1.0.1

NSString *appCurVersion = [infoDictionary objectForKey:@"CFBundleShortVersionString"];

NSLog(@"當前應用軟件版本:%@",appCurVersion);

// 當前應用版本號碼? int類型

NSString *appCurVersionNum = [infoDictionary objectForKey:@"CFBundleVersion"];

NSLog(@"當前應用版本號碼：%@",appCurVersionNum);

54、獲取一個類的所有屬性

id LenderClass = objc_getClass("Lender");

unsigned int outCount, i;

objc_property_t *properties = class_copyPropertyList(LenderClass, &outCount);

for (i = 0; i < outCount; i++) {

objc_property_t property = properties[i];

fprintf(stdout, "%s %s\n", property_getName(property), property_getAttributes(property));

}

55、image圓角

- (UIImage *)circleImage

{

// NO代表透明

UIGraphicsBeginImageContextWithOptions(self.size, NO, 1);

// 獲得上下文

CGContextRef ctx = UIGraphicsGetCurrentContext();

// 添加一個圓

CGRect rect = CGRectMake(0, 0, self.size.width, self.size.height);

// 方形變圓形

CGContextAddEllipseInRect(ctx, rect);

// 裁剪

CGContextClip(ctx);

// 將圖片畫上去

[self drawInRect:rect];

UIImage *image = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

return image;

}

56、image拉伸

+ (UIImage *)resizableImage:(NSString *)imageName

{

UIImage *image = [UIImage imageNamed:imageName];

CGFloat imageW = image.size.width;

CGFloat imageH = image.size.height;

return [image resizableImageWithCapInsets:UIEdgeInsetsMake(imageH * 0.5, imageW * 0.5, imageH * 0.5, imageW * 0.5) resizingMode:UIImageResizingModeStretch];

}

57、JSON字符串轉字典

+ (NSDictionary *)parseJSONStringToNSDictionary:(NSString *)JSONString {

NSData *JSONData = [JSONString dataUsingEncoding:NSUTF8StringEncoding];

NSDictionary *responseJSON = [NSJSONSerialization JSONObjectWithData:JSONData options:NSJSONReadingMutableLeaves error:nil];

return responseJSON;

}

58、身份證號驗證

- (BOOL)validateIdentityCard {

BOOL flag;

if (self.length <= 0) {

flag = NO;

return flag;

}

NSString *regex2 = @"^(\\d{14}|\\d{17})(\\d|[xX])$";

NSPredicate *identityCardPredicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@",regex2];

return [identityCardPredicate evaluateWithObject:self];

}

59、獲取設備mac地址

+ (NSString *)macAddress {

int? ? ? ? ? ? ? ? mib[6];

size_t? ? ? ? ? ? ? len;

char? ? ? ? ? ? ? ? *buf;

unsigned char? ? ? *ptr;

struct if_msghdr? ? *ifm;

struct sockaddr_dl? *sdl;

mib[0] = CTL_NET;

mib[1] = AF_ROUTE;

mib[2] = 0;

mib[3] = AF_LINK;

mib[4] = NET_RT_IFLIST;

if((mib[5] = if_nametoindex("en0")) == 0) {

printf("Error: if_nametoindex error\n");

return NULL;

}

if(sysctl(mib, 6, NULL, &len, NULL, 0) < 0) {

printf("Error: sysctl, take 1\n");

return NULL;

}

if((buf = malloc(len)) == NULL) {

printf("Could not allocate memory. Rrror!\n");

return NULL;

}

if(sysctl(mib, 6, buf, &len, NULL, 0) < 0) {

printf("Error: sysctl, take 2");

return NULL;

}

ifm = (struct if_msghdr *)buf;

sdl = (struct sockaddr_dl *)(ifm + 1);

ptr = (unsigned char *)LLADDR(sdl);

NSString *outstring = [NSString stringWithFormat:@"X:X:X:X:X:X",

*ptr, *(ptr+1), *(ptr+2), *(ptr+3), *(ptr+4), *(ptr+5)];

free(buf);

return outstring;

}

60、導入自定義字體庫

1、找到你想用的字體的 ttf 格式，拖入工程

2、在工程的plist中增加一行數組，“Fonts provided by application”

3、為這個key添加一個item，value為你剛才導入的ttf文件名

4、直接使用即可：label.font = [UIFont fontWithName:@"你剛才導入的ttf文件名" size:20.0]；

61、拿到當前正在顯示的控制器，不管是push進去的，還是present進去的都能拿到

- (UIViewController *)getVisibleViewControllerFrom:(UIViewController*)vc {

if ([vc isKindOfClass:[UINavigationController class]]) {

return [self getVisibleViewControllerFrom:[((UINavigationController*) vc) visibleViewController]];

}else if ([vc isKindOfClass:[UITabBarController class]]){

return [self getVisibleViewControllerFrom:[((UITabBarController*) vc) selectedViewController]];

} else {

if (vc.presentedViewController) {

return [self getVisibleViewControllerFrom:vc.presentedViewController];

} else {

return vc;

}

}

}

62、runtime為一個類動態添加屬性

// 動態添加屬性的本質是: 讓對象的某個屬性與值產生關聯

objc_setAssociatedObject(self, WZBPlaceholderViewKey, placeholderView, OBJC_ASSOCIATION_RETAIN_NONATOMIC);

63、獲取runtime為一個類動態添加的屬性

objc_getAssociatedObject(self, WZBPlaceholderViewKey);

64、KVO監聽某個對象的屬性

// 添加監聽者

[self addObserver:self forKeyPath:property options:NSKeyValueObservingOptionNew context:nil];

// 當監聽的屬性值變化的時候會來到這個方法

- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context {

if ([keyPath isEqualToString:@"property"]) {

[self textViewTextChange];

} else {

}

}

65、Reachability判斷網絡狀態

NetworkStatus status = [[Reachability reachabilityForInternetConnection] currentReachabilityStatus];

if (status == NotReachable) {

NSLog(@"當前設備無網絡");

}

if (status == ReachableViaWiFi) {

NSLog(@"當前wifi網絡");

}

if (status == NotReachable) {

NSLog(@"當前蜂窩移動網絡");

}

66、AFNetworking監聽網絡狀態

// 監聽網絡狀況

AFNetworkReachabilityManager *mgr = [AFNetworkReachabilityManager sharedManager];

[mgr setReachabilityStatusChangeBlock:^(AFNetworkReachabilityStatus status) {

switch (status) {

case AFNetworkReachabilityStatusUnknown:

break;

case AFNetworkReachabilityStatusNotReachable: {

[SVProgressHUD showInfoWithStatus:@"當前設備無網絡"];

}

break;

case AFNetworkReachabilityStatusReachableViaWiFi:

[SVProgressHUD showInfoWithStatus:@"當前Wi-Fi網絡"];

break;

case AFNetworkReachabilityStatusReachableViaWWAN:

[SVProgressHUD showInfoWithStatus:@"當前蜂窩移動網絡"];

break;

default:

break;

}

}];

[mgr startMonitoring];

67、透明顏色不影響子視圖透明度

[UIColor colorWithRed: green: blue: alpha:];

68、取圖片某一點的顏色

if (point.x < 0 || point.y < 0) return nil;

CGImageRef imageRef = self.CGImage;

NSUInteger width = CGImageGetWidth(imageRef);

NSUInteger height = CGImageGetHeight(imageRef);

if (point.x >= width || point.y >= height) return nil;

unsigned char *rawData = malloc(height * width * 4);

if (!rawData) return nil;

CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();

NSUInteger bytesPerPixel = 4;

NSUInteger bytesPerRow = bytesPerPixel * width;

NSUInteger bitsPerComponent = 8;

CGContextRef context = CGBitmapContextCreate(rawData,

width,

height,

bitsPerComponent,

bytesPerRow,

colorSpace,

kCGImageAlphaPremultipliedLast

| kCGBitmapByteOrder32Big);

if (!context) {

free(rawData);

return nil;

}

CGColorSpaceRelease(colorSpace);

CGContextDrawImage(context, CGRectMake(0, 0, width, height), imageRef);

CGContextRelease(context);

int byteIndex = (bytesPerRow * point.y) + point.x * bytesPerPixel;

CGFloat red? = (rawData[byteIndex]? ? * 1.0) / 255.0;

CGFloat green = (rawData[byteIndex + 1] * 1.0) / 255.0;

CGFloat blue? = (rawData[byteIndex + 2] * 1.0) / 255.0;

CGFloat alpha = (rawData[byteIndex + 3] * 1.0) / 255.0;

UIColor *result = nil;

result = [UIColor colorWithRed:red green:green blue:blue alpha:alpha];

free(rawData);

return result;

69、判斷該圖片是否有透明度通道

- (BOOL)hasAlphaChannel

{

CGImageAlphaInfo alpha = CGImageGetAlphaInfo(self.CGImage);

return (alpha == kCGImageAlphaFirst ||

alpha == kCGImageAlphaLast ||

alpha == kCGImageAlphaPremultipliedFirst ||

alpha == kCGImageAlphaPremultipliedLast);

}

70、獲得灰度圖

+ (UIImage*)covertToGrayImageFromImage:(UIImage*)sourceImage

{

int width = sourceImage.size.width;

int height = sourceImage.size.height;

CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceGray();

CGContextRef context = CGBitmapContextCreate (nil,width,height,8,0,colorSpace,kCGImageAlphaNone);

CGColorSpaceRelease(colorSpace);

if (context == NULL) {

return nil;

}

CGContextDrawImage(context,CGRectMake(0, 0, width, height), sourceImage.CGImage);

CGImageRef contextRef = CGBitmapContextCreateImage(context);

UIImage *grayImage = [UIImage imageWithCGImage:contextRef];

CGContextRelease(context);

CGImageRelease(contextRef);

return grayImage;

}

71、根據bundle中的文件名讀取圖片

+ (UIImage *)imageWithFileName:(NSString *)name {

NSString *extension = @"png";

NSArray *components = [name componentsSeparatedByString:@"."];

if ([components count] >= 2) {

NSUInteger lastIndex = components.count - 1;

extension = [components objectAtIndex:lastIndex];

name = [name substringToIndex:(name.length-(extension.length+1))];

}

// 如果為Retina屏幕且存在對應圖片，則返回Retina圖片，否則查找普通圖片

if ([UIScreen mainScreen].scale == 2.0) {

name = [name stringByAppendingString:@"@2x"];

NSString *path = [[NSBundle mainBundle] pathForResource:name ofType:extension];

if (path != nil) {

return [UIImage imageWithContentsOfFile:path];

}

}

if ([UIScreen mainScreen].scale == 3.0) {

name = [name stringByAppendingString:@"@3x"];

NSString *path = [[NSBundle mainBundle] pathForResource:name ofType:extension];

if (path != nil) {

return [UIImage imageWithContentsOfFile:path];

}

}

NSString *path = [[NSBundle mainBundle] pathForResource:name ofType:extension];

if (path) {

return [UIImage imageWithContentsOfFile:path];

}

return nil;

}

72、合并兩個圖片

+ (UIImage*)mergeImage:(UIImage*)firstImage withImage:(UIImage*)secondImage {

CGImageRef firstImageRef = firstImage.CGImage;

CGFloat firstWidth = CGImageGetWidth(firstImageRef);

CGFloat firstHeight = CGImageGetHeight(firstImageRef);

CGImageRef secondImageRef = secondImage.CGImage;

CGFloat secondWidth = CGImageGetWidth(secondImageRef);

CGFloat secondHeight = CGImageGetHeight(secondImageRef);

CGSize mergedSize = CGSizeMake(MAX(firstWidth, secondWidth), MAX(firstHeight, secondHeight));

UIGraphicsBeginImageContext(mergedSize);

[firstImage drawInRect:CGRectMake(0, 0, firstWidth, firstHeight)];

[secondImage drawInRect:CGRectMake(0, 0, secondWidth, secondHeight)];

UIImage *image = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

return image;

}

73、根據bundle中的圖片名創建imageview

+ (id)imageViewWithImageNamed:(NSString*)imageName

{

return [[UIImageView alloc] initWithImage:[UIImage imageNamed:imageName]];

}

74、為imageView添加倒影

CGRect frame = self.frame;

frame.origin.y += (frame.size.height + 1);

UIImageView *reflectionImageView = [[UIImageView alloc] initWithFrame:frame];

self.clipsToBounds = TRUE;

reflectionImageView.contentMode = self.contentMode;

[reflectionImageView setImage:self.image];

reflectionImageView.transform = CGAffineTransformMakeScale(1.0, -1.0);

CALayer *reflectionLayer = [reflectionImageView layer];

CAGradientLayer *gradientLayer = [CAGradientLayer layer];

gradientLayer.bounds = reflectionLayer.bounds;

gradientLayer.position = CGPointMake(reflectionLayer.bounds.size.width / 2, reflectionLayer.bounds.size.height * 0.5);

gradientLayer.colors = [NSArray arrayWithObjects:

(id)[[UIColor clearColor] CGColor],

(id)[[UIColor colorWithRed:1.0 green:1.0 blue:1.0 alpha:0.3] CGColor], nil];

gradientLayer.startPoint = CGPointMake(0.5,0.5);

gradientLayer.endPoint = CGPointMake(0.5,1.0);

reflectionLayer.mask = gradientLayer;

[self.superview addSubview:reflectionImageView];

75、畫水印

// 畫水印

- (void) setImage:(UIImage *)image withWaterMark:(UIImage *)mark inRect:(CGRect)rect

{

if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 4.0)

{

UIGraphicsBeginImageContextWithOptions(self.frame.size, NO, 0.0);

}

//原圖

[image drawInRect:self.bounds];

//水印圖

[mark drawInRect:rect];

UIImage *newPic = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

self.image = newPic;

}

76、讓label的文字內容顯示在左上／右上／左下／右下／中心頂／中心底部

自定義UILabel

// 重寫label的textRectForBounds方法

- (CGRect)textRectForBounds:(CGRect)bounds limitedToNumberOfLines:(NSInteger)numberOfLines {

CGRect rect = [super textRectForBounds:bounds limitedToNumberOfLines:numberOfLines];

switch (self.textAlignmentType) {

case WZBTextAlignmentTypeLeftTop: {

rect.origin = bounds.origin;

}

break;

case WZBTextAlignmentTypeRightTop: {

rect.origin = CGPointMake(CGRectGetMaxX(bounds) - rect.size.width, bounds.origin.y);

}

break;

case WZBTextAlignmentTypeLeftBottom: {

rect.origin = CGPointMake(bounds.origin.x, CGRectGetMaxY(bounds) - rect.size.height);

}

break;

case WZBTextAlignmentTypeRightBottom: {

rect.origin = CGPointMake(CGRectGetMaxX(bounds) - rect.size.width, CGRectGetMaxY(bounds) - rect.size.height);

}

break;

case WZBTextAlignmentTypeTopCenter: {

rect.origin = CGPointMake((CGRectGetWidth(bounds) - CGRectGetWidth(rect)) / 2, CGRectGetMaxY(bounds) - rect.origin.y);

}

break;

case WZBTextAlignmentTypeBottomCenter: {

rect.origin = CGPointMake((CGRectGetWidth(bounds) - CGRectGetWidth(rect)) / 2, CGRectGetMaxY(bounds) - CGRectGetMaxY(bounds) - rect.size.height);

}

break;

case WZBTextAlignmentTypeLeft: {

rect.origin = CGPointMake(0, rect.origin.y);

}

break;

case WZBTextAlignmentTypeRight: {

rect.origin = CGPointMake(rect.origin.x, 0);

}

break;

case WZBTextAlignmentTypeCenter: {

rect.origin = CGPointMake((CGRectGetWidth(bounds) - CGRectGetWidth(rect)) / 2, (CGRectGetHeight(bounds) - CGRectGetHeight(rect)) / 2);

}

break;

default:

break;

}

return rect;

}

- (void)drawTextInRect:(CGRect)rect {

CGRect textRect = [self textRectForBounds:rect limitedToNumberOfLines:self.numberOfLines];

[super drawTextInRect:textRect];

}

77、scrollView上的輸入框，鍵盤擋住的問題

推薦用IQKeyboardManager這個框架！

手動解決如下

1、監聽鍵盤彈出／消失的通知

2、在通知中加入代碼：

NSDictionary* info = [aNotification userInfo];

CGRect keyPadFrame=[[UIApplication sharedApplication].keyWindow convertRect:[[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue] fromView:self.view];

CGSize kbSize =keyPadFrame.size;

CGRect activeRect=[self.view convertRect:activeField.frame fromView:activeField.superview];

CGRect aRect = self.view.bounds;

aRect.size.height -= (kbSize.height);

CGPoint origin =? activeRect.origin;

origin.y -= backScrollView.contentOffset.y;

if (!CGRectContainsPoint(aRect, origin)) {

CGPoint scrollPoint = CGPointMake(0.0,CGRectGetMaxY(activeRect)-(aRect.size.height));

[backScrollView setContentOffset:scrollPoint animated:YES];

}

78、frame布局的cell動態高度

這種通常在你的模型中添加一個輔助屬性cellHeight，在模型中重寫這個屬性的get方法，根據你的布局和模型中的其他屬性值計算出總高度。最后在tableView：heightForRow方法中，根據indexPath找出對應的模型，返回這個高度即可。

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