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关于iOS 的一些总结

發布時間：2023/12/3 综合教程 32 生活家

生活随笔收集整理的這篇文章主要介紹了关于iOS 的一些总结小編覺得挺不錯的,現在分享給大家,幫大家做個參考.

總結了幾個月的東西終于能和大家分享了，不多說，直接看東西！由于比較懶部分直接從別人那里拿來的，在這里感謝一下原作者。不喜勿噴

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0if(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

build phases

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) {UIApplication *application = [UIApplication sharedApplication];NSURL *URL = [NSURL URLWithString:UIApplicationOpenSettingsURLString];if ([application respondsToSelector:@selector(openURL:options:completionHandler:)]) {[application openURL:URL options:@{}
                       completionHandler:nil];} else {[application 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MCGFloat 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:@"%02X:%02X:%02X:%02X:%02X:%02X",*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 == ReachableViaWWAN) {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:<#(CGFloat)#> green:<#(CGFloat)#> blue:<#(CGFloat)#> alpha:<#(CGFloat)#>];

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;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:[ 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。

79、AutoLayout布局的cell動態高度

// 1、設置tableView的屬性
self.tableView.rowHeight = UITableViewAutomaticDimension;
self.tableView.estimatedRowHeight = 44.0; // 這個屬性非0，估計cell高度

// 2、至上而下設置cell的約束，注意，上下左右最好都要頂到cell的四周

cell

80、使用performSelector:調用函數，內存泄漏問題

當我們在開發中使用[obj performSelector:NSSelectorFromString(@"aMethod")];這類方法時可能會收到一個警告"performSelector may cause a leak because its selector is unknown".
是因為編譯器不清楚這個對象能不能相應這個方法，如果不能，則是不安全的，而且編譯器也不清楚該怎么處理這個方法的返回值！

使用以下代碼調用即可：
if (! obj) { return; }
SEL selector = NSSelectorFromString(@"aMethod");
IMP imp = [obj methodForSelector:selector];
void (*func)(id, SEL) = (void *)imp;
func(obj, selector);或者：
SEL selector = NSSelectorFromString(@"aMethod");
((void (*)(id, SEL))[obj methodForSelector:selector])(obj, selector);

81、一個字符串是否包含另一個字符串

// 方法1
if ([str1 containsString:str2]) {NSLog(@"str1包含str2");} else {NSLog(@"str1不包含str2");}// 方法2
if ([str1 rangeOfString: str2].location == NSNotFound) {NSLog(@"str1不包含str2");} else {NSLog(@"str1包含str2");}

82、cell去除選中效果

cell.selectionStyle = UITableViewCellSelectionStyleNone;

83、cell點按效果

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {[tableView deselectRowAtIndexPath:indexPath animated:YES];
}

84、當刪除一個從xib拖出來的屬性時，一定記得把xib中對應的線也刪掉，不然會報類似[<ViewController 0x7fea6ed05980> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key的crash

點擊這個叉號刪除

85、真機測試的時候報錯：Could not launch "你的 App"，process launch failed: Security

因為你的app沒有上線，iOS9開始，需要手動信任Xcode生成的描述文件，打開手機設置->通用->描述文件->點擊你的app的描述文件->點擊信任

86、真機測試的時候報錯：Could not find Developer Disk Image

這是因為你的設備系統版本大于Xcode能兼容的系統版本，比如你的設備是iOS10.3，而Xcode版本是8.2（Xcode8.2最大兼容iOS10.2），就會報這個錯誤。解決辦法就是升級Xcode！

87、UITextView沒有placeholder的問題？

網上有很多此類自定義控件，也可以參考下我寫的一個UITextView分類 UITextView-WZB

88、移除字符串中的空格和換行

+ (NSString *)removeSpaceAndNewline:(NSString *)str {NSString *temp = [str stringByReplacingOccurrencesOfString:@" " withString:@""];temp = [temp stringByReplacingOccurrencesOfString:@"\r" withString:@""];temp = [temp stringByReplacingOccurrencesOfString:@"\n" withString:@""];return temp;
}

89、判斷字符串中是否有空格

+ (BOOL)isBlank:(NSString *)str {NSRange _range = [str rangeOfString:@" "];if (_range.location != NSNotFound) {//有空格return YES;} else {//沒有空格return NO;}
}

90、獲取一個視頻的第一幀圖片

    NSURL *url = [NSURL URLWithString:filepath];AVURLAsset *asset1 = [[AVURLAsset alloc] initWithURL:url options:nil];AVAssetImageGenerator *generate1 = [[AVAssetImageGenerator alloc] initWithAsset:asset1];generate1.appliesPreferredTrackTransform = YES;NSError *err = NULL;CMTime time = CMTimeMake(1, 2);CGImageRef oneRef = [generate1 copyCGImageAtTime:time actualTime:NULL error:&err];UIImage *one = [[UIImage alloc] initWithCGImage:oneRef];return one;

91、獲取視頻的時長

+ (NSInteger)getVideoTimeByUrlString:(NSString *)urlString {NSURL *videoUrl = [NSURL URLWithString:urlString];AVURLAsset *avUrl = [AVURLAsset assetWithURL:videoUrl];CMTime time = [avUrl duration];int seconds = ceil(time.value/time.timescale);return seconds;
}

92、字符串是否為空

+ (BOOL)isEqualToNil:(NSString *)str {return str.length <= 0 || [str isEqualToString:@""] || !str;
}

93、將app上傳到App Store的時候通常會遇到這個問題

try again

很多人說這事蘋果爸爸服務器問題，重復嘗試幾次，總會成功的！
但是經過嘗試發現如果使用Application Loader上傳成功率就非常高，所以還是推薦把ipa文件導出直接用Application Loader上傳。
如果Application Loader也不行，需要檢查下自己的網絡，有時候vpn也會提高速度。

94、當tableView占不滿一屏時，去除下邊多余的單元格

self.tableView.tableHeaderView = [UIView new];
self.tableView.tableFooterView = [UIView new];

95、isKindOfClass和isMemberOfClass的區別

isKindOfClass可以判斷某個對象是否屬于某個類，或者這個類的子類。
isMemberOfClass更加精準，它只能判斷這個對象類型是否為這個類(不能判斷子類)

96、__block

當一個局部變量需要在block里改變時，需要在定義時加上__block修飾，具體請看官方文檔 http://developer.apple.com/library/ios/documentation/cocoa/Conceptual/Blocks/Articles/bxVariables.html#//apple_ref/doc/uid/TP40007502-CH6-SW6

97、-[ViewController aMethod:]: unrecognized selector sent to instance 0x7fe91e607fb0

這是一個經典錯誤，ViewController不能響應aMethod這個方法，錯誤原因可能viewController文件中沒有實現aMethod這個方法

98、UITableView (<UITableView: 0x7ff19b027000; >) failed to obtain a cell from its dataSource (<ViewController: 0x7ff19a507520>)

這個錯誤原因是tableView的代理方法-tableView:cellForRowAtIndexPath:需要返回一個UITableViewCell,而你返回了一個nil。另外這個地方返回值不是UITableViewCell類型也會導致崩潰

99、約束如何做UIView動畫？

1、把需要改的約束Constraint拖條線出來，成為屬性
2、在需要動畫的地方加入代碼，改變此屬性的constant屬性
3、開始做UIView動畫，動畫里邊調用layoutIfNeeded方法@property (weak, nonatomic) IBOutlet NSLayoutConstraint *buttonTopConstraint;
self.buttonTopConstraint.constant = 100;[UIView animateWithDuration:.5 animations:^{[self.view layoutIfNeeded];}];

100、從NSURL中拿到鏈接字符串

NSString *urlString = myURL.absoluteString;

101、將tableView滾動到頂部

[tableView setContentOffset:CGPointZero animated:YES];
或者
[tableView scrollRectToVisible:CGRectMake(0, 0, 1, 1) animated:YES];

102、如果用addTarget:action:forControlEvents:方法為一個button添加了很多點擊事件，在某個時刻想一次刪除怎么辦？只需要調用下邊這句代碼

[youButton removeTarget:nil action:nil forControlEvents:UIControlEventAllEvents];

103、某個字體的高度

font.lineHeight;

104、刪除某個view所有的子視圖

[[someView subviews]makeObjectsPerformSelector:@selector(removeFromSuperview)];

105、刪除NSUserDefaults所有記錄

//方法一NSString *appDomain = [[NSBundle mainBundle] bundleIdentifier];[[NSUserDefaults standardUserDefaults] removePersistentDomainForName:appDomain];   //方法二  
- (void)resetDefaults {   NSUserDefaults * defs = [NSUserDefaults standardUserDefaults];NSDictionary * dict = [defs dictionaryRepresentation];for (id key in dict) {[defs removeObjectForKey:key];}[defs synchronize];}
// 方法三
[[NSUserDefaults standardUserDefaults] setPersistentDomain:[NSDictionary dictionary] forName:[[NSBundle mainBundle] bundleIdentifier]];

106、禁用系統滑動返回功能

- (void)viewDidAppear:(BOOL)animated
{[super viewDidAppear:animated];
if ([self.navigationController respondsToSelector:@selector(interactivePopGestureRecognizer)]) {self.navigationController.interactivePopGestureRecognizer.delegate = self;}
}- (void)viewWillDisappear:(BOOL)animated {[super viewWillDisappear:animated];if ([self.navigationController respondsToSelector:@selector(interactivePopGestureRecognizer)]) {self.navigationController.interactivePopGestureRecognizer.delegate = nil;}
}
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
{return NO;
}

107、模擬器報錯

模擬器報錯

解決辦法：
打開模擬器->Simulator->Reset Content and Settings...
如果不行，就重啟試試！

108、自定義cell選中背景顏色

UIView *bgColorView = [[UIView alloc] init];
bgColorView.backgroundColor = [UIColor redColor];
[cell setSelectedBackgroundView:bgColorView];

109、UILabel設置內邊距

子類化UILabel，重寫drawTextInRect方法
- (void)drawTextInRect:(CGRect)rect {// 邊距，上左下右UIEdgeInsets insets = {0, 5, 0, 5};[super drawTextInRect:UIEdgeInsetsInsetRect(rect, insets)];
}

110、UILabel設置文字描邊

子類化UILabel，重寫drawTextInRect方法
- (void)drawTextInRect:(CGRect)rect
{CGContextRef c = UIGraphicsGetCurrentContext();// 設置描邊寬度CGContextSetLineWidth(c, 1);CGContextSetLineJoin(c, kCGLineJoinRound);CGContextSetTextDrawingMode(c, kCGTextStroke);// 描邊顏色self.textColor = [UIColor redColor];[super drawTextInRect:rect];// 文本顏色self.textColor = [UIColor yellowColor];CGContextSetTextDrawingMode(c, kCGTextFill);[super drawTextInRect:rect];
}

111、使用模擬器截圖

快捷鍵command + s
或者File->Save Screen Shot

112、scrollView滾動到最下邊

CGPoint bottomOffset = CGPointMake(0, scrollView.contentSize.height - scrollView.bounds.size.height);
[scrollView setContentOffset:bottomOffset animated:YES];

113、UIView背景顏色漸變

    UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 100)];[self.view addSubview:view];CAGradientLayer *gradient = [CAGradientLayer layer];gradient.frame = view.bounds;gradient.colors = [NSArray arrayWithObjects:(id)[[UIColor blackColor] CGColor], (id)[[UIColor whiteColor] CGColor], nil];[view.layer insertSublayer:gradient atIndex:0];

114、停止UIView動畫

[yourView.layer removeAllAnimations]

115、為UIView某個角添加圓角

// 左上角和右下角添加圓角
UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:view.bounds byRoundingCorners:(UIRectCornerTopLeft | UIRectCornerBottomRight) cornerRadii:CGSizeMake(20, 20)];CAShapeLayer *maskLayer = [CAShapeLayer layer];maskLayer.frame = view.bounds;maskLayer.path = maskPath.CGPath;view.layer.mask = maskLayer;

116、刪除Xcode Derived data緩存數據

依次點擊Xcode -> Preferences -> location，然后點擊 Derived data路徑后到小箭頭，刪除這個文件夾下的數據就可以了，如圖

Xcode Derived data

117、將一個view放置在其兄弟視圖的最上面

[parentView bringSubviewToFront:yourView]

118、將一個view放置在其兄弟視圖的最下面

[parentView sendSubviewToBack:yourView]

119、讓手機震動一下

倒入框架
#import <AudioToolbox/AudioToolbox.h>
AudioServicesPlayAlertSound(kSystemSoundID_Vibrate);
或者
AudioServicesPlaySystemSound(kSystemSoundID_Vibrate);

120、layoutSubviews方法什么時候調用？

1、init方法不會調用
2、addSubview方法等時候會調用
3、bounds改變的時候調用
4、scrollView滾動的時候會調用scrollView的layoutSubviews方法(所以不建議在scrollView的layoutSubviews方法中做復雜邏輯)
5、旋轉設備的時候調用
6、子視圖被移除的時候調用
參考請看：http://blog.logichigh.com/2011/03/16/when-does-layoutsubviews-get-called/

121、讓UILabel在指定的地方換行

// 換行符為\n,在需要換行的地方加上這個符號即可，如 
label.numberOfLines = 0;
label.text = @"此處\n換行";

122、搖一搖功能

1、打開搖一搖功能[UIApplication sharedApplication].applicationSupportsShakeToEdit = YES;
2、讓需要搖動的控制器成為第一響應者
[self becomeFirstResponder];
3、實現以下方法// 開始搖動
- (void)motionBegan:(UIEventSubtype)motion withEvent:(UIEvent *)event
// 取消搖動
- (void)motionCancelled:(UIEventSubtype)motion withEvent:(UIEvent *)event
// 搖動結束
- (void)motionEnded:(UIEventSubtype)motion withEvent:(UIEvent *)event

123、獲取圖片大小

CGFloat imageWidth = image.size.width;CGFloat imageHeight = imageWidth * image.scale;

124、獲取view的坐標在整個window上的位置

// v上的(0, 0)點在toView上的位置
CGPoint point = [v convertPoint:CGPointMake(0, 0) toView:[UIApplication sharedApplication].windows.lastObject];
或者
CGPoint point = [v.superview convertPoint:v.frame.origin toView:[UIApplication sharedApplication].windows.lastObject];

125、提交App Store審核程序限制

您的應用程序的未壓縮大小必須小于4GB。每個Mach-O可執行文件（例如app_name.app/app_name）不能超過這些限制：
對于MinimumOSVersion小于7.0的應用程序：TEXT二進制文件中所有部分的總數最多為80 MB 。
對于MinimumOSVersion7.x到8.x的應用程序：TEXT對于二進制文件中每個體系結構片段的每個片段，最大為60 MB 。
對于MinimumOSVersion9.0或更高版本的應用程序：__TEXT二進制文件中所有部分的總數最多為500 MB 。參閱：iTunes Connect開發者指南

126、修改UISegmentedControl的字體大小

[segment setTitleTextAttributes:@{NSFontAttributeName : [UIFont systemFontOfSize:15.0f]} forState:UIControlStateNormal];

127、在非ViewController的地方彈出UIAlertController對話框

//  最好抽成一個分類
UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"Title" message:@"message" preferredStyle:UIAlertControllerStyleAlert];
//...
id rootViewController = [UIApplication sharedApplication].delegate.window.rootViewController;
if([rootViewController isKindOfClass:[UINavigationController class]])
{rootViewController = ((UINavigationController *)rootViewController).viewControllers.firstObject;
}
if([rootViewController isKindOfClass:[UITabBarController class]])
{rootViewController = ((UITabBarController *)rootViewController).selectedViewController;
}
[rootViewController presentViewController:alertController animated:YES completion:nil];

128、獲取一個view所屬的控制器

// view分類方法
- (UIViewController *)belongViewController {for (UIView *next = [self superview]; next; next = next.superview) {UIResponder* nextResponder = [next nextResponder];if ([nextResponder isKindOfClass:[UIViewController class]]) {return (UIViewController *)nextResponder;}}return nil;
}

129、UIImage和base64互轉

// view分類方法
- (NSString *)encodeToBase64String:(UIImage *)image {return [UIImagePNGRepresentation(image) base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
}- (UIImage *)decodeBase64ToImage:(NSString *)strEncodeData {NSData *data = [[NSData alloc]initWithBase64EncodedString:strEncodeData options:NSDataBase64DecodingIgnoreUnknownCharacters];return [UIImage imageWithData:data];
}

130、UIWebView設置背景透明

[webView setBackgroundColor:[UIColor clearColor]];
[webView setOpaque:NO];

131、判斷NSDate是不是今天

NSDateComponents *otherDay = [[NSCalendar currentCalendar] components:NSCalendarUnitEra | NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay fromDate:aDate];
NSDateComponents *today = [[NSCalendar currentCalendar] components:NSCalendarUnitEra | NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay fromDate:[NSDate date]];
if([today day] == [otherDay day] &&[today month] == [otherDay month] &&[today year] == [otherDay year] &&[today era] == [otherDay era]) {// 是今天
}

132、設置tableView分割線顏色

[self.tableView setSeparatorColor:[UIColor myColor]];

133、設置屏幕方向

 NSNumber *orientationTarget = [NSNumber numberWithInt:UIInterfaceOrientationLandscapeLeft];
[[UIDevice currentDevice] setValue:orientationTarget forKey:@"orientation"];
[UIViewController attemptRotationToDeviceOrientation];

134、比較兩個顏色是否相等

- (BOOL)isEqualToColor:(UIColor *)otherColor {CGColorSpaceRef colorSpaceRGB = CGColorSpaceCreateDeviceRGB();UIColor *(^convertColorToRGBSpace)(UIColor*) = ^(UIColor *color) {if (CGColorSpaceGetModel(CGColorGetColorSpace(color.CGColor)) == kCGColorSpaceModelMonochrome) {const CGFloat *oldComponents = CGColorGetComponents(color.CGColor);CGFloat components[4] = {oldComponents[0], oldComponents[0], oldComponents[0], oldComponents[1]};CGColorRef colorRef = CGColorCreate( colorSpaceRGB, components );UIColor *color = [UIColor colorWithCGColor:colorRef];CGColorRelease(colorRef);return color;            } elsereturn color;};UIColor *selfColor = convertColorToRGBSpace(self);otherColor = convertColorToRGBSpace(otherColor);CGColorSpaceRelease(colorSpaceRGB);return [selfColor isEqual:otherColor];
}

135、tableViewCell分割線頂到頭

- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath {[cell setSeparatorInset:UIEdgeInsetsZero];[cell setLayoutMargins:UIEdgeInsetsZero];cell.preservesSuperviewLayoutMargins = NO;
}- (void)viewDidLayoutSubviews {[self.tableView setSeparatorInset:UIEdgeInsetsZero];[self.tableView setLayoutMargins:UIEdgeInsetsZero];
}

136、不讓控制器的view隨著控制器的xib拉伸或壓縮

self.view.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;

137、cocoaPods報錯 : [!] Unable to add a source with url `https://github.com/CocoaPods/Specs.git` named`master-1`.

You can try adding it manually in ~/.cocoapods/repos or via pod repo add.

解決方法：這是因為電腦里安裝了另外一個Xcode導致cocoapods找不到路徑了
在終端執行 sudo xcode-select -switch /Applications/Xcode.app 即可

138、安裝cocoapods的時候出現 ERROR: While executing gem ... (Errno::EPERM)

Operation not permitted - /usr/bin/pod

解決辦法：直接在終端執行 sudo gem install -n /usr/local/bin cocoapods

139、在狀態欄增加網絡請求的菊花，類似safari加載網頁的時候狀態欄菊花

[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;

140、檢查一個rect是否包含一個point

// point是否在rect內
BOOL isContains = CGRectContainsPoint(rect, point);

141、在指定的寬度下，讓UILabel自動設置最佳font

label.adjustsFontSizeToFitWidth = YES;

142、將一個image保存在相冊中

UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil);或者
#import <Photos/Photos.h>
[[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{PHAssetChangeRequest *changeRequest = [PHAssetChangeRequest creationRequestForAssetFromImage:image];changeRequest.creationDate          = [NSDate date];} completionHandler:^(BOOL success, NSError *error) {if (success) {NSLog(@"successfully saved");}else {NSLog(@"error saving to photos: %@", error);}}];

143、修改cell.imageView的大小

UIImage *icon = [UIImage imageNamed:@""];
CGSize itemSize = CGSizeMake(30, 30);
UIGraphicsBeginImageContextWithOptions(itemSize, NO ,0.0);
CGRect imageRect = CGRectMake(0.0, 0.0, itemSize.width, itemSize.height);
[icon drawInRect:imageRect];
cell.imageView.image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

144、為一個view添加虛線邊框

 CAShapeLayer *border = [CAShapeLayer layer];border.strokeColor = [UIColor colorWithRed:67/255.0f green:37/255.0f blue:83/255.0f alpha:1].CGColor;border.fillColor = nil;border.lineDashPattern = @[@4, @2];border.path = [UIBezierPath bezierPathWithRect:view.bounds].CGPath;
    border.frame = view.bounds;
    [view.layer addSublayer:border];

145、UITextView中打開或禁用復制，剪切，選擇，全選等功能

// 繼承UITextView重寫這個方法
- (BOOL)canPerformAction:(SEL)action withSender:(id)sender
{
// 返回NO為禁用，YES為開啟// 粘貼if (action == @selector(paste:)) return NO;// 剪切if (action == @selector(cut:)) return NO;// 復制if (action == @selector(copy:)) return NO;// 選擇if (action == @selector(select:)) return NO;// 選中全部if (action == @selector(selectAll:)) return NO;// 刪除if (action == @selector(delete:)) return NO;// 分享if (action == @selector(share)) return NO;return [super canPerformAction:action withSender:sender];
}

總結

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