iOS 開發經驗 - 轉載
1、禁止手機睡眠 [UIApplication sharedApplication].idleTimerDisabled = YES;2、隱藏某行cell - (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath{// 如果是你需要隱藏的那一行,返回高度為0 if(indexPath.row == YouWantToHideRow) return 0; return 44;}// 然後再你需要隱藏cell的時候呼叫[self.tableView beginUpdates];[self.tableView endUpdates]; 3、禁用button高亮
是因為你的cell被呼叫的早了。先迴圈使用了cell,後又建立cell。順序錯了
可能原因:1、xib的cell沒有註冊 2、記憶體中已經有這個cell的快取了(也就是說通過你的cellId找到的cell並不是你想要的型別),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:原因可能是網路問題,網路請求超時了,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
是因為編譯的時候,在此路徑下找不到這個檔案,解決這個問題,首先是是要檢查缺少的檔案是不是在工程中,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中搜索這個檔案,這時候很可能會搜出現兩個相同的檔案,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,然後重新往工程裡拖進這個檔案即可
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,裡面什麼不寫也行- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {} 12、三個通知
NSSystemTimeZoneDidChangeNotification監聽修改時間介面的兩個按鈕狀態變化
UIApplicationSignificantTimeChangeNotification 監聽使用者改變時間 (只要點選自動設定按鈕就會呼叫) NSSystemClockDidChangeNotification 監聽使用者修改時間(時間不同才會呼叫)
13、SDWebImage本地快取有時候會害人。如果之前快取過一張圖片,即使下次伺服器換了這張圖片,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,不要先去懟伺服器,清空下快取再試就好了。 14、上線前注意:
1)、刪掉程式碼中所有的測試程式碼
2)、如果後臺有稽核模式,提醒後臺開啟此模式
3)、主流程再跑一跑
4)、全域性搜尋waring,檢查所有標記waring的地方
15、跳進app許可權設定 // 跳進app設定 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重新設定,而不是直接更改高度。正確的做法是重新設定一下tableView.tableFooterView = 更改過高度的view。為什麼?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、注意物件為nil的時候,呼叫此物件分類的方法不會執行 19、collectionView的內容小於其寬高的時候是不能滾動的,設定可以滾動: collectionView.alwaysBounceHorizontal = YES;collectionView.alwaysBounceVertical = YES; 20、設定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設定圓角 #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程式碼只執行一次 #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、在主執行緒上執行 #define kDISPATCH_MAIN_THREAD(mainQueueBlock) dispatch_async(dispatch_get_main_queue(), mainQueueBlock); 35、開啟非同步執行緒 #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的字型顏色、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、控制螢幕旋轉,在控制器中寫 /** 是否支援自動旋轉螢幕 */- (BOOL)shouldAutorotate { return YES;}/** 支援哪些螢幕方向 */- (UIInterfaceOrientationMask)supportedInterfaceOrientations { return UIInterfaceOrientationMaskLandscapeLeft | UIInterfaceOrientationMaskLandscapeRight;}/** 預設的螢幕方向(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,才會呼叫這個方法) */- (UIInterfaceOrientation)preferredInterfaceOrientationForPresentation { return UIInterfaceOrientationLandscapeLeft | UIInterfaceOrientationLandscapeRight;}42、獲取app快取大小 - (CGFloat)getCachSize { NSUInteger imageCacheSize = [[SDImageCache sharedImageCache] getSize]; //獲取自定義快取大小 //用列舉器遍歷 一個資料夾的內容 //1.獲取 資料夾列舉器 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;//自定義所有快取大小 } // 得到是位元組 轉化為MCGFloat totalSize = ((CGFloat)imageCacheSize+count)/1024/1024; return totalSize;} 43、清理app快取 - (void)handleClearView { //刪除兩部分 //1.刪除 sd 圖片快取 //先清除記憶體中的圖片快取 [[SDImageCache sharedImageCache] clearMemory]; //清除磁碟的快取 [[SDImageCache sharedImageCache] clearDisk]; //2.刪除自己快取 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、列印百分號和引號 NSLog(@"%%"); NSLog(@"/""); 47、幾個常用許可權判斷 if ([CLLocationManager authorizationStatus] ==kCLAuthorizationStatusDenied) { NSLog(@"沒有定位許可權"); } AVAuthorizationStatus statusVideo = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo]; if (statusVideo == AVAuthorizationStatusDenied) { NSLog(@"沒有攝像頭許可權"); }//是否有麥克風許可權 AVAuthorizationStatus statusAudio = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeAudio]; if (statusAudio == AVAuthorizationStatusDenied) { NSLog(@"沒有錄音許可權"); } [PHPhotoLibrary requestAuthorization:^(PHAuthorizationStatus status) { if (status == PHAuthorizationStatusDenied) { NSLog(@"沒有相簿許可權"); } }]; 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佔,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、長按複製功能 - (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 = @"需要複製的文字"; }}50、cocoapods升級
在終端執行 sudo gem install -n / usr / local / bin cocoapods --pre
51、設定啟動頁後,依然顯示之前的
刪除app,手機重啟,重新安裝
52、判斷圖片型別 //通過圖片Data資料第一個位元組 來獲取圖片副檔名- (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資訊 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: 使用者定義的名稱NSString* userPhoneName = [[UIDevice currentDevice] name]; NSLog(@"手機別名: %@", userPhoneName); //裝置名稱 NSString* deviceName = [[UIDevice currentDevice] systemName]; NSLog(@"裝置名稱: %@",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); // 當前應用軟體版本 比如:1.0.1 NSString *appCurVersion = [infoDictionary objectForKey:@"CFBundleShortVersionString"]; NSLog(@"當前應用軟體版本:%@",appCurVersion); // 當前應用版本號碼 int型別 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(); // 新增一個圓 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、獲取裝置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、匯入自定義字型庫
1、找到你想用的字型的 ttf 格式,拖入工程
2、在工程的plist中增加一行陣列,“Fonts provided by application”
3、為這個key新增一個item,value為你剛才匯入的ttf檔名
4、直接使用即可:label.font = [UIFont fontWithName:@"你剛才匯入的ttf檔名" 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為一個類動態新增屬性 // 動態新增屬性的本質是: 讓物件的某個屬性與值產生關聯 objc_setAssociatedObject(self, WZBPlaceholderViewKey, placeholderView, OBJC_ASSOCIATION_RETAIN_NONATOMIC); 63、獲取runtime為一個類動態新增的屬性 objc_getAssociatedObject(self, WZBPlaceholderViewKey); 64、KVO監聽某個物件的屬性 // 新增監聽者[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判斷網路狀態 NetworkStatus status = [[Reachability reachabilityForInternetConnection] currentReachabilityStatus]; if (status == NotReachable) { NSLog(@"當前裝置無網路"); } if (status == ReachableViaWiFi) { NSLog(@"當前wifi網路"); } if (status == ReachableViaWWAN) { NSLog(@"當前蜂窩行動網路"); } 66、AFNetworking監聽網路狀態 // 監聽網路狀況 AFNetworkReachabilityManager *mgr = [AFNetworkReachabilityManager sharedManager]; [mgr setReachabilityStatusChangeBlock:^(AFNetworkReachabilityStatus status) {switch (status) { case AFNetworkReachabilityStatusUnknown: break; case AFNetworkReachabilityStatusNotReachable: { [SVProgressHUD showInfoWithStatus:@"當前裝置無網路"]; } break; case AFNetworkReachabilityStatusReachableViaWiFi: [SVProgressHUD showInfoWithStatus:@"當前Wi-Fi網路"]; break; case AFNetworkReachabilityStatusReachableViaWWAN: [SVProgressHUD showInfoWithStatus:@"當前蜂窩行動網路"]; break; default: break; } }]; [mgr startMonitoring]; 67、透明顏色不影響子檢視透明度 [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中的檔名讀取圖片 + (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螢幕且存在對應圖片,則返回Retina圖片,否則查詢普通圖片 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、合併兩個圖片 + (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中的圖片名建立imageview + (id)imageViewWithImageNamed:(NSString*)imageName{ return [[UIImageView alloc] initWithImage:[UIImage imageNamed:imageName]];}74、為imageView新增倒影 CGRect frame = self.frame; frame.origin.y += (frame.size.height + 1); UIImageView *reflectionImageView = [[UIImageView alloc] initWithFrame:frame]; self.clipsToBounds = TRUE; reflectionImageView.contentMode = self.contentMode; [reflectionImageView setImage:self.image]; reflectionImageView.transform = CGAffineTransformMakeScale(1.0, -1.0); CALayer *reflectionLayer = [reflectionImageView layer]; CAGradientLayer *gradientLayer = [CAGradientLayer layer]; gradientLayer.bounds = reflectionLayer.bounds; gradientLayer.position = CGPointMake(reflectionLayer.bounds.size.width / 2, reflectionLayer.bounds.size.height * 0.5); gradientLayer.colors = [NSArray arrayWithObjects: (id)[[UIColor clearColor] CGColor], (id)[[UIColor colorWithRed:1.0 green:1.0 blue:1.0 alpha:0.3] CGColor], nil]; gradientLayer.startPoint = CGPointMake(0.5,0.5); gradientLayer.endPoint = CGPointMake(0.5,1.0); reflectionLayer.mask = gradientLayer; [self.superview addSubview:reflectionImageView]; 75、畫水印 // 畫水印- (void) setImage:(UIImage *)image withWaterMark:(UIImage *)mark inRect:(CGRect)rect{ if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 4.0) {UIGraphicsBeginImageContextWithOptions(self.frame.size, NO, 0.0); } //原圖 [image drawInRect:self.bounds]; //水印圖 [mark drawInRect:rect]; UIImage *newPic = UIGraphicsGetImageFromCurrentImageContext();UIGraphicsEndImageContext(); self.image = newPic;} 76、讓label的文字內容顯示在左上/右上/左下/右下/中心頂/中心底部 自定義UILabel// 重寫label的textRectForBounds方法- (CGRect)textRectForBounds:(CGRect)bounds limitedToNumberOfLines:(NSInteger)numberOfLines { CGRect rect = [super textRectForBounds:bounds limitedToNumberOfLines:numberOfLines]; switch (self.textAlignmentType) { case WZBTextAlignmentTypeLeftTop: { rect.origin = bounds.origin; } break; case WZBTextAlignmentTypeRightTop: { rect.origin = CGPointMake(CGRectGetMaxX(bounds) - rect.size.width, bounds.origin.y); } break; case WZBTextAlignmentTypeLeftBottom: { rect.origin = CGPointMake(bounds.origin.x, CGRectGetMaxY(bounds) - rect.size.height); }break; case WZBTextAlignmentTypeRightBottom: { rect.origin = CGPointMake(CGRectGetMaxX(bounds) - rect.size.width, CGRectGetMaxY(bounds) - rect.size.height); } break; case WZBTextAlignmentTypeTopCenter: { rect.origin = CGPointMake((CGRectGetWidth(bounds) - CGRectGetWidth(rect)) / 2, CGRectGetMaxY(bounds) - rect.origin.y); } break; case WZBTextAlignmentTypeBottomCenter: { rect.origin = CGPointMake((CGRectGetWidth(bounds) - CGRectGetWidth(rect)) / 2, CGRectGetMaxY(bounds) - CGRectGetMaxY(bounds) - rect.size.height); }break; case WZBTextAlignmentTypeLeft: { rect.origin = CGPointMake(0, rect.origin.y); } break; case WZBTextAlignmentTypeRight: { rect.origin = CGPointMake(rect.origin.x, 0); } break; case WZBTextAlignmentTypeCenter: {rect.origin = CGPointMake((CGRectGetWidth(bounds) - CGRectGetWidth(rect)) / 2, (CGRectGetHeight(bounds) - CGRectGetHeight(rect)) / 2); } break; default: break; } return rect;}- (void)drawTextInRect:(CGRect)rect { CGRect textRect = [self textRectForBounds:rect limitedToNumberOfLines:self.numberOfLines]; [super drawTextInRect:textRect];} 77、scrollView上的輸入框,鍵盤擋住的問題 推薦用IQKeyboardManager這個框架!手動解決如下1、監聽鍵盤彈出/消失的通知2、在通知中加入程式碼:NSDictionary* info = [aNotification userInfo];CGRect keyPadFrame=[[UIApplication sharedApplication].keyWindow convertRect:[[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue] fromView:self.view];CGSize kbSize =keyPadFrame.size;CGRect activeRect=[self.view convertRect:activeField.frame fromView:activeField.superview];CGRect aRect = self.view.bounds;aRect.size.height -= (kbSize.height);CGPoint origin = activeRect.origin;origin.y -= backScrollView.contentOffset.y;if (!CGRectContainsPoint(aRect, origin)) { CGPoint scrollPoint = CGPointMake(0.0,CGRectGetMaxY(activeRect)-(aRect.size.height)); [backScrollView setContentOffset:scrollPoint animated:YES];} 78、frame佈局的cell動態高度
這種通常在你的模型中新增一個輔助屬性cellHeight,在模型中重寫這個屬性的get方法,根據你的佈局和模型中的其他屬性值計算出總高度。最後在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佈局的cell動態高度 // 1、設定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、至上而下設定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:呼叫函式,記憶體洩漏問題
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物件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麼處理這個方法的返回值!
使用以下程式碼呼叫即可: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、一個字串是否包含另一個字串 // 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 
點選這個叉號刪除 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生成的描述檔案,開啟手機設定->通用->描述檔案->點選你的app的描述檔案->點選信任
86、真機測試的時候報錯:Could not find Developer Disk Image
這是因為你的裝置系統版本大於Xcode能相容的系統版本,比如你的裝置是iOS10.3,而Xcode版本是8.2(Xcode8.2最大相容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制元件,也可以參考下我寫的一個UITextView分類 UITextView-WZB
88、移除字串中的空格和換行 + (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、獲取一個視訊的第一幀圖片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、獲取視訊的時長 + (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伺服器問題,重複嘗試幾次,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檔案匯出直接用Application Loader上傳。
如果Application Loader也不行,需要檢查下自己的網路,有時候vpn也會提高速度。
94、當tableView佔不滿一屏時,去除下邊多餘的單元格self.tableView.tableHeaderView = [UIView new];self.tableView.tableFooterView = [UIView new]; 95、isKindOfClass和isMemberOfClass的區別 isKindOfClass可以判斷某個物件是否屬於某個類,或者這個類的子類。isMemberOfClass更加精準,它只能判斷這個物件型別是否為這個類(不能判斷子類) 96、__block
當一個區域性變數需要在block裡改變時,需要在定義時加上__block修飾,具體請看官方文件 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檔案中沒有實現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型別也會導致崩潰
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程式碼,改變此屬性的constant屬性3、開始做UIView動畫,動畫裡邊呼叫layoutIfNeeded方法@property (weak, nonatomic) IBOutlet NSLayoutConstraint *buttonTopConstraint;self.buttonTopConstraint.constant = 100; [UIView animateWithDuration:.5 animations:^{ [self.view layoutIfNeeded]; }]; 100、從NSURL中拿到連結字串 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添加了很多點選事件,在某個時刻想一次刪除怎麼辦?只需要呼叫下邊這句程式碼 [youButton removeTarget:nil action:nil forControlEvents:UIControlEventAllEvents]; 103、某個字型的高度font.lineHeight; 104、刪除某個view所有的子檢視 [[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:
開啟模擬器->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設定內邊距 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設定文字描邊 子類化UILabel,重寫drawTextInRect方法- (void)drawTextInRect:(CGRect)rect{ CGContextRef c = UIGraphicsGetCurrentContext(); // 設定描邊寬度 CGContextSetLineWidth(c, 1); CGContextSetLineJoin(c, kCGLineJoinRound); CGContextSetTextDrawingMode(c, kCGTextStroke); // 描邊顏色 self.textColor = [UIColor redColor]; [super drawTextInRect:rect]; // 文字顏色 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某個角新增圓角 // 左上角和右下角新增圓角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快取資料
依次點選Xcode -> Preferences -> location,然後點選 Derived data路徑後到小箭頭,刪除這個資料夾下的資料就可以了,如圖
Xcode Derived data
117、將一個view放置在其兄弟檢視的最上面 [parentView bringSubviewToFront:yourView] 118、將一個view放置在其兄弟檢視的最下面[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方法什麼時候呼叫?
1、init方法不會呼叫
2、addSubview方法等時候會呼叫
3、bounds改變的時候呼叫
4、scrollView滾動的時候會呼叫scrollView的layoutSubviews方法(所以不建議在scrollView的layoutSubviews方法中做複雜邏輯)
5、旋轉裝置的時候呼叫
6、子檢視被移除的時候呼叫
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、開啟搖一搖功能 [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的座標在整個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稽核程式限制
您的應用程式的未壓縮大小必須小於4GB。每個Mach-O可執行檔案(例如app_name.app/app_name)不能超過這些限制:
對於MinimumOSVersion小於7.0的應用程式:TEXT二進位制檔案中所有部分的總數最多為80 MB 。
對於MinimumOSVersion7.x到8.x的應用程式:TEXT對於二進位制檔案中每個體系結構片段的每個片段,最大為60 MB 。
對於MinimumOSVersion9.0或更高版本的應用程式:__TEXT二進位制檔案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的字型大小 [segment setTitleTextAttributes:@{NSFontAttributeName : [UIFont systemFontOfSize:15.0f]} forState:UIControlStateNormal]; 127、在非ViewController的地方彈出UIAlertController對話方塊 // 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設定背景透明 [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、設定tableView分割線顏色 [self.tableView setSeparatorColor:[UIColor myColor]]; 133、設定螢幕方向 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; } else return 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:這是因為電腦裡安裝了另外一個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、在狀態列增加網路請求的菊花,類似safari載入網頁的時候狀態列菊花[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自動設定最佳font label.adjustsFontSizeToFitWidth = YES; 142、將一個image儲存在相簿中 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新增虛線邊框 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中開啟或禁用複製,剪下,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 // 貼上 if (action == @selector(paste:)) return NO; // 剪下 if (action == @selector(cut:)) return NO; // 複製 if (action == @selector(copy:)) return NO; // 選擇 if (action == @selector(select:)) return NO; // 選中全