iOS开发总结

1、禁止手机睡眠
[UIApplication sharedApplication].idleTimerDisabled = YES;

2、隐藏某行cell

  • (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath{// 如果是你需要隐藏的那一行,返回高度为0 if(indexPath.row == YouWantToHideRow) return 0; return 44;}// 然后再你需要隐藏cell的时候调用[self.tableView beginUpdates];[self.tableView endUpdates];

3、禁用button高亮
button.adjustsImageWhenHighlighted = NO;或者在创建的时候 UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];

4、tableview遇到这种报错failed to obtain a cell from its dataSource
是因为你的cell被调用的早了。先循环使用了cell,后又创建cell。顺序错了可能原因:1、xib的cell没有注册 2、内存中已经有这个cell的缓存了(也就是说通过你的cellId找到的cell并不是你想要的类型),这时候需要改下cell的标识

5、cocoa pods报这个错误:unable to access 'https://github.com/facebook/pop.git/': Operation timed out after 0 milliseconds with 0 out of 0 bytes received
解决办法:原因可能是网络问题,网络请求超时了,只需要重试就行了

6、cocoa pods 出现ERROR: While executing gem ... (Errno::EPERM)
解决办法:https://segmentfault.com/q/1010000002926243

7、动画切换window的根控制器
// options是动画选项[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、去除数组中重复的对象
NSArray *newArr = [oldArr valueForKeyPath:@“@distinctUnionOfObjects.self"];

9、编译的时候遇到 no such file or directory: /users/apple/XXX
是因为编译的时候,在此路径下找不到这个文件,解决这个问题,首先是是要检查缺少的文件是不是在工程中,如果不在工程中,需要从本地拖进去,如果发现已经存在工程中了,或者拖进去还是报错,这时候需要去build phases中搜索这个文件,这时候很可能会搜出现两个相同的文件,这时候,有一个路径是正确的,删除另外一个即可。如果删除了还是不行,需要把两个都删掉,然后重新往工程里拖进这个文件即可

Sbuild phases

10、iOS8系统中,tableView最好实现下-tableView: heightForRowAtIndexPath:这个代理方法,要不然在iOS8中可能就会出现显示不全或者无法响应事件的问题
11、iOS8中实现侧滑功能的时候这个方法必须实现,要不然在iOS8中无法侧滑
// 必须写的方法,和editActionsForRowAtIndexPath配对使用,里面什么不写也行- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {}

12、三个通知
NSSystemTimeZoneDidChangeNotification监听修改时间界面的两个按钮状态变化UIApplicationSignificantTimeChangeNotification 监听用户改变时间 (只要点击自动设置按钮就会调用) NSSystemClockDidChangeNotification 监听用户修改时间(时间不同才会调用)

13、SDWebImage本地缓存有时候会害人。如果之前缓存过一张图片,即使下次服务器换了这张图片,但是图片url没换,用sdwebimage下载下来的还是以前那张,所以遇到这种问题,不要先去怼服务器,清空下缓存再试就好了。
14、上线前注意:
1)、删掉代码中所有的测试代码2)、如果后台有审核模式,提醒后台开启此模式3)、主流程再跑一跑4)、全局搜索waring,检查所有标记waring的地方

15、跳进app权限设置
// 跳进app设置 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、给一个view截图
UIGraphicsBeginImageContextWithOptions(view.bounds.size, YES, 0.0); [view.layer renderInContext:UIGraphicsGetCurrentContext()]; UIImage *img = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext();

17、开发中如果要动态修改tableView的tableHeaderView或者tableFooterView的高度,需要给tableView重新设置,而不是直接更改高度。正确的做法是重新设置一下tableView.tableFooterView = 更改过高度的view。为什么?其实在iOS8以上直接改高度是没有问题的,在iOS8中出现了contentSize不准确的问题,这是解决办法。
18、注意对象为nil的时候,调用此对象分类的方法不会执行
19、collectionView的内容小于其宽高的时候是不能滚动的,设置可以滚动:
collectionView.alwaysBounceHorizontal = YES;collectionView.alwaysBounceVertical = YES;

20、设置navigationBar上的title颜色和大小
[self.navigationController.navigationBar setTitleTextAttributes:@{NSForegroundColorAttributeName : [UIColor youColor], NSFontAttributeName : [UIFont systemFontOfSize:15]}]

21、颜色转图片

  • (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设置圆角

define ViewBorderRadius(View, Radius, Width, Color)\[View.layer setCornerRadius:(Radius)];[View.layer setMasksToBounds:YES];[View.layer setBorderWidth:(Width)];[View.layer setBorderColor:[Color CGColor]] // view圆角

23、强/弱引用

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

24、由角度转换弧度

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

25、由弧度转换角度

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

26、获取图片资源

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

27、获取temp

define PathTemp NSTemporaryDirectory()

28、获取沙盒 Document

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

29、获取沙盒 Cache

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

30、GCD代码只执行一次

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

31、自定义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、在主线程上运行

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

35、开启异步线程

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、随机颜色

  • (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、获取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的字体颜色、大小
[textField setValue:[UIColor redColor] forKeyPath:@"_placeholderLabel.textColor"];[textField setValue:[UIFont boldSystemFontOfSize:16] forKeyPath:@"_placeholderLabel.font"];

40、统一收起键盘
[[[UIApplication sharedApplication] keyWindow] endEditing:YES];

41、控制屏幕旋转,在控制器中写
/** 是否支持自动转屏 /- (BOOL)shouldAutorotate { return YES;}/* 支持哪些屏幕方向 /- (UIInterfaceOrientationMask)supportedInterfaceOrientations { return UIInterfaceOrientationMaskLandscapeLeft | UIInterfaceOrientationMaskLandscapeRight;}/* 默认的屏幕方向(当前ViewController必须是通过模态出来的UIViewController(模态带导航的无效)方式展现出来的,才会调用这个方法) */- (UIInterfaceOrientation)preferredInterfaceOrientationForPresentation { return UIInterfaceOrientationLandscapeLeft | UIInterfaceOrientationLandscapeRight;}

42、获取app缓存大小

  • (CGFloat)getCachSize { NSUInteger imageCacheSize = [[SDImageCache sharedImageCache] getSize]; //获取自定义缓存大小 //用枚举器遍历 一个文件夹的内容 //1.获取 文件夹枚举器 NSString *myCachePath = [NSHomeDirectory() stringByAppendingPathComponent:@"Library/Caches"]; NSDirectoryEnumerator *enumerator = [[NSFileManager defaultManager] enumeratorAtPath:myCachePath]; __block NSUInteger count = 0; //2.遍历 for (NSString *fileName in enumerator) { NSString *path = [myCachePath stringByAppendingPathComponent:fileName]; NSDictionary *fileDict = [[NSFileManager defaultManager] attributesOfItemAtPath:path error:nil]; count += fileDict.fileSize;//自定义所有缓存大小 } // 得到是字节 转化为M CGFloat totalSize = ((CGFloat)imageCacheSize+count)/1024/1024; return totalSize;}

43、清理app缓存

  • (void)handleClearView { //删除两部分 //1.删除 sd 图片缓存 //先清除内存中的图片缓存 [[SDImageCache sharedImageCache] clearMemory]; //清除磁盘的缓存 [[SDImageCache sharedImageCache] clearDisk]; //2.删除自己缓存 NSString *myCachePath = [NSHomeDirectory() stringByAppendingPathComponent:@"Library/Caches"]; [[NSFileManager defaultManager] removeItemAtPath:myCachePath error:nil];}

44、模型转字典
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); // 获得父类 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) { // 集合中没有NSObject,因为几乎所有的类都是继承自NSObject,具体是不是NSObject需要特殊判断 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、交换两个方法实现
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、打印百分号和引号
NSLog(@"%%"); NSLog(@""");

47、几个常用权限判断
if ([CLLocationManager authorizationStatus] ==kCLAuthorizationStatusDenied) { NSLog(@"没有定位权限"); } AVAuthorizationStatus statusVideo = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo]; if (statusVideo == AVAuthorizationStatusDenied) { NSLog(@"没有摄像头权限"); } //是否有麦克风权限 AVAuthorizationStatus statusAudio = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeAudio]; if (statusAudio == AVAuthorizationStatusDenied) { NSLog(@"没有录音权限"); } [PHPhotoLibrary requestAuthorization:^(PHAuthorizationStatus status) { if (status == PHAuthorizationStatusDenied) { NSLog(@"没有相册权限"); } }];

48、获取手机型号

  • (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"; // 日行两款手机型号均为日本独占,可能使用索尼FeliCa支付方案而不是苹果支付 if ([platform isEqualToString:@"iPhone9,1"]) return @"国行、日版、港行iPhone 7"; if ([platform isEqualToString:@"iPhone9,2"]) return @"港行、国行iPhone 7 Plus"; if ([platform isEqualToString:@"iPhone9,3"]) return @"美版、台版iPhone 7"; if ([platform isEqualToString:@"iPhone9,4"]) return @"美版、台版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、长按复制功能

  • (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 = @"需要复制的文本"; }}

50、cocoapods升级
在终端执行 sudo gem install -n / usr / local / bin cocoapods --pre

51、设置启动页后,依然显示之前的
删除app,手机重启,重新安装

52、判断图片类型
//通过图片Data数据第一个字节 来获取图片扩展名- (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、获取手机和app信息
NSDictionary infoDictionary = [[NSBundle mainBundle] infoDictionary]; CFShow(infoDictionary); // app名称 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"]; //手机序列号 NSString identifierNumber = [[UIDevice currentDevice] uniqueIdentifier]; NSLog(@"手机序列号: %@",identifierNumber); //手机别名: 用户定义的名称 NSString userPhoneName = [[UIDevice currentDevice] name]; NSLog(@"手机别名: %@", userPhoneName); //设备名称 NSString deviceName = [[UIDevice currentDevice] systemName]; NSLog(@"设备名称: %@",deviceName ); //手机系统版本 NSString phoneVersion = [[UIDevice currentDevice] systemVersion]; NSLog(@"手机系统版本: %@", phoneVersion); //手机型号 NSString* phoneModel = [[UIDevice currentDevice] model]; NSLog(@"手机型号: %@",phoneModel ); //地方型号 (国际化区域名称) NSString* localPhoneModel = [[UIDevice currentDevice] localizedModel]; NSLog(@"国际化区域名称: %@",localPhoneModel ); NSDictionary *infoDictionary = [[NSBundle mainBundle] infoDictionary]; // 当前应用名称 NSString *appCurName = [infoDictionary objectForKey:@"CFBundleDisplayName"]; NSLog(@"当前应用名称:%@",appCurName); // 当前应用软件版本 比如:1.0.1 NSString *appCurVersion = [infoDictionary objectForKey:@"CFBundleShortVersionString"]; NSLog(@"当前应用软件版本:%@",appCurVersion); // 当前应用版本号码 int类型 NSString *appCurVersionNum = [infoDictionary objectForKey:@"CFBundleVersion"]; NSLog(@"当前应用版本号码:%@",appCurVersionNum);

54、获取一个类的所有属性
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圆角

  • (UIImage *)circleImage{ // NO代表透明 UIGraphicsBeginImageContextWithOptions(self.size, NO, 1); // 获得上下文 CGContextRef ctx = UIGraphicsGetCurrentContext(); // 添加一个圆 CGRect rect = CGRectMake(0, 0, self.size.width, self.size.height); // 方形变圆形 CGContextAddEllipseInRect(ctx, rect); // 裁剪 CGContextClip(ctx); // 将图片画上去 [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字符串转字典

  • (NSDictionary *)parseJSONStringToNSDictionary:(NSString *)JSONString { NSData *JSONData = [JSONString dataUsingEncoding:NSUTF8StringEncoding]; NSDictionary *responseJSON = [NSJSONSerialization JSONObjectWithData:JSONData options:NSJSONReadingMutableLeaves error:nil]; return responseJSON;}

58、身份证号验证

  • (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、获取设备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、导入自定义字体库
1、找到你想用的字体的 ttf 格式,拖入工程2、在工程的plist中增加一行数组,“Fonts provided by application”3、为这个key添加一个item,value为你刚才导入的ttf文件名4、直接使用即可:label.font = [UIFont fontWithName:@"你刚才导入的ttf文件名" size:20.0];

61、拿到当前正在显示的控制器,不管是push进去的,还是present进去的都能拿到

  • (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为一个类动态添加属性
// 动态添加属性的本质是: 让对象的某个属性与值产生关联 objc_setAssociatedObject(self, WZBPlaceholderViewKey, placeholderView, OBJC_ASSOCIATION_RETAIN_NONATOMIC);

63、获取runtime为一个类动态添加的属性
objc_getAssociatedObject(self, WZBPlaceholderViewKey);

64、KVO监听某个对象的属性
// 添加监听者[self addObserver:self forKeyPath:property options:NSKeyValueObservingOptionNew context:nil];// 当监听的属性值变化的时候会来到这个方法- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context { if ([keyPath isEqualToString:@"property"]) { [self textViewTextChange]; } else { }}

65、Reachability判断网络状态
NetworkStatus status = [[Reachability reachabilityForInternetConnection] currentReachabilityStatus]; if (status == NotReachable) { NSLog(@"当前设备无网络"); } if (status == ReachableViaWiFi) { NSLog(@"当前wifi网络"); } if (status == ReachableViaWWAN) { NSLog(@"当前蜂窝移动网络"); }

66、AFNetworking监听网络状态
// 监听网络状况 AFNetworkReachabilityManager *mgr = [AFNetworkReachabilityManager sharedManager]; [mgr setReachabilityStatusChangeBlock:^(AFNetworkReachabilityStatus status) { switch (status) { case AFNetworkReachabilityStatusUnknown: break; case AFNetworkReachabilityStatusNotReachable: { [SVProgressHUD showInfoWithStatus:@"当前设备无网络"]; } break; case AFNetworkReachabilityStatusReachableViaWiFi: [SVProgressHUD showInfoWithStatus:@"当前Wi-Fi网络"]; break; case AFNetworkReachabilityStatusReachableViaWWAN: [SVProgressHUD showInfoWithStatus:@"当前蜂窝移动网络"]; break; default: break; } }]; [mgr startMonitoring];

67、透明颜色不影响子视图透明度
[UIColor colorWithRed:<#(CGFloat)#> green:<#(CGFloat)#> blue:<#(CGFloat)#> alpha:<#(CGFloat)#>];

68、取图片某一点的颜色
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、判断该图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、获得灰度图

  • (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、根据bundle中的文件名读取图片

  • (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))]; } // 如果为Retina屏幕且存在对应图片,则返回Retina图片,否则查找普通图片 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、合并两个图片

  • (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、根据bundle中的图片名创建imageview

  • (id)imageViewWithImageNamed:(NSString*)imageName{ return [[UIImageView alloc] initWithImage:[UIImage imageNamed:imageName]];}

74、为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、画水印
// 画水印- (void) setImage:(UIImage *)image withWaterMark:(UIImage *)mark inRect:(CGRect)rect{ if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 4.0) { UIGraphicsBeginImageContextWithOptions(self.frame.size, NO, 0.0); } //原图 [image drawInRect:self.bounds]; //水印图 [mark drawInRect:rect]; UIImage *newPic = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); self.image = newPic;}

76、让label的文字内容显示在左上/右上/左下/右下/中心顶/中心底部
自定义UILabel// 重写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上的输入框,键盘挡住的问题
推荐用IQKeyboardManager这个框架!手动解决如下1、监听键盘弹出/消失的通知2、在通知中加入代码: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动态高度
这种通常在你的模型中添加一个辅助属性cellHeight,在模型中重写这个属性的get方法,根据你的布局和模型中的其他属性值计算出总高度。最后在tableView:heightForRow方法中,根据indexPath找出对应的模型,返回这个高度即可。

79、AutoLayout布局的cell动态高度
// 1、设置tableView的属性self.tableView.rowHeight = UITableViewAutomaticDimension;self.tableView.estimatedRowHeight = 44.0; // 这个属性非0,估计cell高度

// 2、至上而下设置cell的约束,注意,上下左右最好都要顶到cell的四周

Scell

80、使用performSelector:调用函数,内存泄漏问题
当我们在开发中使用[obj performSelector:NSSelectorFromString(@"aMethod")];这类方法时可能会收到一个警告"performSelector may cause a leak because its selector is unknown".是因为编译器不清楚这个对象能不能相应这个方法,如果不能,则是不安全的,而且编译器也不清楚该怎么处理这个方法的返回值!

使用以下代码调用即可: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、一个字符串是否包含另一个字符串
// 方法1if ([str1 containsString:str2]) { NSLog(@"str1包含str2"); } else { NSLog(@"str1不包含str2"); }// 方法2if ([str1 rangeOfString: str2].location == NSNotFound) { NSLog(@"str1不包含str2"); } else { NSLog(@"str1包含str2"); }

82、cell去除选中效果
cell.selectionStyle = UITableViewCellSelectionStyleNone;

83、cell点按效果

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

84、当删除一个从xib拖出来的属性时,一定记得把xib中对应的线也删掉,不然会报类似[<ViewController 0x7fea6ed05980> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key的crash


点击这个叉号删除

85、真机测试的时候报错:Could not launch "你的 App",process launch failed: Security
因为你的app没有上线,iOS9开始,需要手动信任Xcode生成的描述文件,打开手机设置->通用->描述文件->点击你的app的描述文件->点击信任

86、真机测试的时候报错:Could not find Developer Disk Image
这是因为你的设备系统版本大于Xcode能兼容的系统版本,比如你的设备是iOS10.3,而Xcode版本是8.2(Xcode8.2最大兼容iOS10.2),就会报这个错误。解决办法就是升级Xcode!

87、UITextView没有placeholder的问题?
网上有很多此类自定义控件,也可以参考下我写的一个UITextView分类 UITextView-WZB

88、移除字符串中的空格和换行

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

89、判断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 { //没有空格 return NO; }}

90、获取一个视频的第一帧图片
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、获取视频的时长

  • (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、字符串是否为空

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

93、将app上传到App Store的时候通常会遇到这个问题


try again

很多人说这事苹果爸爸服务器问题,重复尝试几次,总会成功的!但是经过尝试发现如果使用Application Loader上传成功率就非常高,所以还是推荐把ipa文件导出直接用Application Loader上传。如果Application Loader也不行,需要检查下自己的网络,有时候vpn也会提高速度。

94、当tableView占不满一屏时,去除下边多余的单元格
self.tableView.tableHeaderView = [UIView new];self.tableView.tableFooterView = [UIView new];

95、isKindOfClass和isMemberOfClass的区别
isKindOfClass可以判断某个对象是否属于某个类,或者这个类的子类。isMemberOfClass更加精准,它只能判断这个对象类型是否为这个类(不能判断子类)

96、__block
当一个局部变量需要在block里改变时,需要在定义时加上__block修饰,具体请看官方文档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
这是一个经典错误,ViewController不能响应aMethod这个方法,错误原因可能viewController文件中没有实现aMethod这个方法

98、UITableView (<UITableView: 0x7ff19b027000; >) failed to obtain a cell from its dataSource (<ViewController: 0x7ff19a507520>)
这个错误原因是tableView的代理方法-tableView:cellForRowAtIndexPath:需要返回一个UITableViewCell,而你返回了一个nil。另外这个地方返回值不是UITableViewCell类型也会导致崩溃

99、约束如何做UIView动画?
1、把需要改的约束Constraint拖条线出来,成为属性2、在需要动画的地方加入代码,改变此属性的constant属性3、开始做UIView动画,动画里边调用layoutIfNeeded方法@property (weak, nonatomic) IBOutlet NSLayoutConstraint *buttonTopConstraint;self.buttonTopConstraint.constant = 100; [UIView animateWithDuration:.5 animations:^{ [self.view layoutIfNeeded]; }];

100、从NSURL中拿到链接字符串
NSString *urlString = myURL.absoluteString;

101、将tableView滚动到顶部
[tableView setContentOffset:CGPointZero animated:YES];或者[tableView scrollRectToVisible:CGRectMake(0, 0, 1, 1) animated:YES];

102、如果用addTarget:action:forControlEvents:方法为一个button添加了很多点击事件,在某个时刻想一次删除怎么办?只需要调用下边这句代码
[youButton removeTarget:nil action:nil forControlEvents:UIControlEventAllEvents];

103、某个字体的高度
font.lineHeight;

104、删除某个view所有的子视图
[[someView subviews] makeObjectsPerformSelector:@selector(removeFromSuperview)];

105、删除NSUserDefaults所有记录
//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、禁用系统滑动返回功能

  • (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、模拟器报错


模拟器报错

解决办法:打开模拟器->Simulator->Reset Content and Settings...如果不行,就重启试试!

108、自定义cell选中背景颜色
UIView *bgColorView = [[UIView alloc] init];bgColorView.backgroundColor = [UIColor redColor];[cell setSelectedBackgroundView:bgColorView];

109、UILabel设置内边距
子类化UILabel,重写drawTextInRect方法- (void)drawTextInRect:(CGRect)rect { // 边距,上左下右 UIEdgeInsets insets = {0, 5, 0, 5}; [super drawTextInRect:UIEdgeInsetsInsetRect(rect, insets)];}

110、UILabel设置文字描边
子类化UILabel,重写drawTextInRect方法- (void)drawTextInRect:(CGRect)rect{ CGContextRef c = UIGraphicsGetCurrentContext(); // 设置描边宽度 CGContextSetLineWidth(c, 1); CGContextSetLineJoin(c, kCGLineJoinRound); CGContextSetTextDrawingMode(c, kCGTextStroke); // 描边颜色 self.textColor = [UIColor redColor]; [super drawTextInRect:rect]; // 文本颜色 self.textColor = [UIColor yellowColor]; CGContextSetTextDrawingMode(c, kCGTextFill); [super drawTextInRect:rect];}

111、使用模拟器截图
快捷键command + s或者File->Save Screen Shot

112、scrollView滚动到最下边
CGPoint bottomOffset = CGPointMake(0, scrollView.contentSize.height - scrollView.bounds.size.height);[scrollView setContentOffset:bottomOffset animated:YES];

113、UIView背景颜色渐变
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动画
[yourView.layer removeAllAnimations]

115、为UIView某个角添加圆角
// 左上角和右下角添加圆角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、删除Xcode Derived data缓存数据
依次点击Xcode -> Preferences -> location,然后点击 Derived data路径后到小箭头,删除这个文件夹下的数据就可以了,如图


Xcode Derived data

117、将一个view放置在其兄弟视图的最上面
[parentView bringSubviewToFront:yourView]

118、将一个view放置在其兄弟视图的最下面
[parentView sendSubviewToBack:yourView]

119、让手机震动一下
倒入框架#import <AudioToolbox/AudioToolbox.h>AudioServicesPlayAlertSound(kSystemSoundID_Vibrate);或者AudioServicesPlaySystemSound(kSystemSoundID_Vibrate);

120、layoutSubviews方法什么时候调用?
1、init方法不会调用2、addSubview方法等时候会调用3、bounds改变的时候调用4、scrollView滚动的时候会调用scrollView的layoutSubviews方法(所以不建议在scrollView的layoutSubviews方法中做复杂逻辑)5、旋转设备的时候调用6、子视图被移除的时候调用参考请看:http://blog.logichigh.com/2011/03/16/when-does-layoutsubviews-get-called/

121、让UILabel在指定的地方换行
// 换行符为\n,在需要换行的地方加上这个符号即可,如 label.numberOfLines = 0;label.text = @"此处\n换行";

122、摇一摇功能
1、打开摇一摇功能 [UIApplication sharedApplication].applicationSupportsShakeToEdit = YES;2、让需要摇动的控制器成为第一响应者[self becomeFirstResponder];3、实现以下方法// 开始摇动- (void)motionBegan:(UIEventSubtype)motion withEvent:(UIEvent *)event// 取消摇动- (void)motionCancelled:(UIEventSubtype)motion withEvent:(UIEvent *)event// 摇动结束- (void)motionEnded:(UIEventSubtype)motion withEvent:(UIEvent *)event

123、获取图片大小
CGFloat imageWidth = image.size.width; CGFloat imageHeight = imageWidth * image.scale;

124、获取view的坐标在整个window上的位置
// v上的(0, 0)点在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审核程序限制
您的应用程序的未压缩大小必须小于4GB。每个Mach-O可执行文件(例如app_name.app/app_name)不能超过这些限制:对于MinimumOSVersion小于7.0的应用程序:TEXT二进制文件中所有部分的总数最多为80 MB 。对于MinimumOSVersion7.x到8.x的应用程序:TEXT对于二进制文件中每个体系结构片段的每个片段,最大为60 MB 。对于MinimumOSVersion9.0或更高版本的应用程序:__TEXT二进制文件中所有部分的总数最多为500 MB 。参阅:iTunes Connect开发者指南

126、修改UISegmentedControl的字体大小
[segment setTitleTextAttributes:@{NSFontAttributeName : [UIFont systemFontOfSize:15.0f]} forState:UIControlStateNormal];

127、在非ViewController的地方弹出UIAlertController对话框
// 最好抽成一个分类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、获取一个view所属的控制器
// view分类方法- (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互转
// view分类方法- (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设置背景透明
[webView setBackgroundColor:[UIColor clearColor]];[webView setOpaque:NO];

131、判断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、设置tableView分割线颜色
[self.tableView setSeparatorColor:[UIColor myColor]];

133、设置屏幕方向
[[UIDevice currentDevice] setValue:@(UIInterfaceOrientationLandscapeLeft) forKey:@"orientation"];

134、比较两个颜色是否相等

  • (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; } else return color; }; UIColor *selfColor = convertColorToRGBSpace(self); otherColor = convertColorToRGBSpace(otherColor); CGColorSpaceRelease(colorSpaceRGB); return [selfColor isEqual:otherColor];}

135、tableViewCell分割线顶到头

  • (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、不让控制器的view随着控制器的xib拉伸或压缩
self.view.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;

137、cocoaPods报错 : [!] 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
.
解决方法:这是因为电脑里安装了另外一个Xcode导致cocoapods找不到路径了在终端执行 sudo xcode-select -switch /Applications/Xcode.app 即可

138、安装cocoapods的时候出现 ERROR: While executing gem ... (Errno::EPERM)
Operation not permitted - /usr/bin/pod

解决办法:直接在终端执行 sudo gem install -n /usr/local/bin cocoapods

139、在状态栏增加网络请求的菊花,类似safari加载网页的时候状态栏菊花
[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;

140、检查一个rect是否包含一个point
// point是否在rect内BOOL isContains = CGRectContainsPoint(rect, point);

141、在指定的宽度下,让UILabel自动设置最佳font
label.adjustsFontSizeToFitWidth = YES;

142、将一个image保存在相册中
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、为一个view添加虚线边框
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中打开或禁用复制,剪切,选择,全选等功能
// 继承UITextView重写这个方法- (BOOL)canPerformAction:(SEL)action withSender:(id)sender{// 返回NO为禁用,YES为开启 // 粘贴 if (action == @selector(paste:)) return NO; // 剪切 if (action == @selector(cut:)) return NO; // 复制 if (action == @selector(copy:)) return NO; // 选择 if (action == @selector(select:)) return NO; // 选中全部 if (action == @selector(selectAll:)) return NO; // 删除 if (action == @selector(delete:)) return NO; // 分享 if (action == @selector(share)) return NO; return [super canPerformAction:action withSender:sender];}

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