首页 > 代码库 > 在这里总结一些iOS开发中的小技巧,能大大方便我们的开发,持续更新。
在这里总结一些iOS开发中的小技巧,能大大方便我们的开发,持续更新。
UITableView的Group样式下顶部空白处理 //分组列表头部空白处理 UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 0, 0.1)]; self.tableView.tableHeaderView = view; UITableView的plain样式下,取消区头停滞效果 - (void)scrollViewDidScroll:(UIScrollView *)scrollView { CGFloat sectionHeaderHeight = sectionHead.height; if (scrollView.contentOffset.y=0) { scrollView.contentInset = UIEdgeInsetsMake(-scrollView.contentOffset.y, 0, 0, 0); } else if(scrollView.contentOffset.y>=sectionHeaderHeight) { scrollView.contentInset = UIEdgeInsetsMake(-sectionHeaderHeight, 0, 0, 0); } } 那个,其实,还是用Group样式吧哈哈。 获取某个view所在的控制器 - (UIViewController *)viewController { UIViewController *viewController = nil; UIResponder *next = self.nextResponder; while (next) { if ([next isKindOfClass:[UIViewController class]]) { viewController = (UIViewController *)next; break; } next = next.nextResponder; } return viewController; } 两种方法删除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]; } 打印系统所有已注册的字体名称 #pragma mark - 打印系统所有已注册的字体名称 void enumerateFonts() { for(NSString *familyName in [UIFont familyNames]) { NSLog(@"%@",familyName); NSArray *fontNames = [UIFont fontNamesForFamilyName:familyName]; for(NSString *fontName in fontNames) { NSLog(@"\t|- %@",fontName); } } } 获取图片某一点的颜色 - (UIColor*) getPixelColorAtLocation:(CGPoint)point inImage:(UIImage *)image { UIColor* color = nil; CGImageRef inImage = image.CGImage; CGContextRef cgctx = [self createARGBBitmapContextFromImage:inImage]; if (cgctx == NULL) { return nil; /* error */ } size_t w = CGImageGetWidth(inImage); size_t h = CGImageGetHeight(inImage); CGRect rect = {{0,0},{w,h}}; CGContextDrawImage(cgctx, rect, inImage); unsigned char* data = http://www.mamicode.com/CGBitmapContextGetData (cgctx);"%c", ch]; } return newString; } //第二种: - (NSString*)reverseWordsInString:(NSString*)str { NSMutableString *reverString = [NSMutableString stringWithCapacity:str.length]; [str enumerateSubstringsInRange:NSMakeRange(0, str.length) options:NSStringEnumerationReverse |NSStringEnumerationByComposedCharacterSequences usingBlock:^(NSString *substring, NSRange substringRange,NSRange enclosingRange, BOOL *stop) { [reverString appendString:substring]; }]; return reverString; } 禁止锁屏, 默认情况下,当设备一段时间没有触控动作时,iOS会锁住屏幕。但有一些应用是不需要锁屏的,比如视频播放器。 [UIApplication sharedApplication].idleTimerDisabled = YES; 或 [[UIApplication sharedApplication] setIdleTimerDisabled:YES]; 模态推出透明界面 UIViewController *vc = [[UIViewController alloc] init]; UINavigationController *na = [[UINavigationController alloc] initWithRootViewController:vc]; if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 8.0) { na.modalPresentationStyle = UIModalPresentationOverCurrentContext; } else { self.modalPresentationStyle=UIModalPresentationCurrentContext; } [self presentViewController:na animated:YES completion:nil]; Xcode调试不显示内存占用 editSCheme 里面有个选项叫叫做enable zoombie Objects 取消选中 显示隐藏文件 //显示 defaults write com.apple.finder AppleShowAllFiles -bool true killall Finder //隐藏 defaults write com.apple.finder AppleShowAllFiles -bool false killall Finder 字符串按多个符号分割 iOS跳转到App Store下载应用评分 [[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"itms-apps://itunes.apple.com/WebObjects/MZStore.woa/wa/viewContentsUserReviews?type=Purple+Software&id=APPID"]]; iOS 获取汉字的拼音 + (NSString *)transform:(NSString *)chinese { //将NSString装换成NSMutableString NSMutableString *pinyin = [chinese mutableCopy]; //将汉字转换为拼音(带音标) CFStringTransform((__bridge CFMutableStringRef)pinyin, NULL, kCFStringTransformMandarinLatin, NO); NSLog(@"%@", pinyin); //去掉拼音的音标 CFStringTransform((__bridge CFMutableStringRef)pinyin, NULL, kCFStringTransformStripCombiningMarks, NO); NSLog(@"%@", pinyin); //返回最近结果 return pinyin; } 手动更改iOS状态栏的颜色 - (void)setStatusBarBackgroundColor:(UIColor *)color { UIView *statusBar = [[[UIApplication sharedApplication] valueForKey:@"statusBarWindow"] valueForKey:@"statusBar"]; if ([statusBar respondsToSelector:@selector(setBackgroundColor:)]) { statusBar.backgroundColor = color; } } 判断当前ViewController是push还是present的方式显示的 NSArray *viewcontrollers=self.navigationController.viewControllers; if (viewcontrollers.count > 1) { if ([viewcontrollers objectAtIndex:viewcontrollers.count - 1] == self) { //push方式 [self.navigationController popViewControllerAnimated:YES]; } } else { //present方式 [self dismissViewControllerAnimated:YES completion:nil]; } 获取实际使用的LaunchImage图片 - (NSString *)getLaunchImageName { CGSize viewSize = self.window.bounds.size; // 竖屏 NSString *viewOrientation = @"Portrait"; NSString *launchImageName = nil; NSArray* imagesDict = [[[NSBundle mainBundle] infoDictionary] valueForKey:@"UILaunchImages"]; for (NSDictionary* dict in imagesDict) { CGSize imageSize = CGSizeFromString(dict[@"UILaunchImageSize"]); if (CGSizeEqualToSize(imageSize, viewSize) && [viewOrientationisEqualToString:dict[@"UILaunchImageOrientation"]]) { launchImageName = dict[@"UILaunchImageName"]; } } return launchImageName; } iOS在当前屏幕获取第一响应 UIWindow * keyWindow = [[UIApplication sharedApplication] keyWindow]; UIView * firstResponder = [keyWindow performSelector:@selector(firstResponder)]; 判断对象是否遵循了某协议 if ([self.selectedController conformsToProtocol:@protocol(RefreshPtotocol)]) { [self.selectedController performSelector:@selector(onTriggerRefresh)]; } 判断view是不是指定视图的子视图 BOOL isView = [textView isDescendantOfView:self.view]; NSArray 快速求总和 最大值 最小值 和 平均值 NSArray *array = [NSArray arrayWithObjects:@"2.0", @"2.3", @"3.0", @"4.0", @"10", nil]; CGFloat sum = [[array valueForKeyPath:@"@sum.floatValue"] floatValue]; CGFloat avg = [[array valueForKeyPath:@"@avg.floatValue"] floatValue]; CGFloat max =[[array valueForKeyPath:@"@max.floatValue"] floatValue]; CGFloat min =[[array valueForKeyPath:@"@min.floatValue"] floatValue]; NSLog(@"%f\n%f\n%f\n%f",sum,avg,max,min); 修改UITextField中Placeholder的文字颜色 [textField setValue:[UIColor redColor] forKeyPath:@"_placeholderLabel.textColor"]; 关于NSDateFormatter的格式 G: 公元时代,例如AD公元 yy: 年的后2位 yyyy: 完整年 MM: 月,显示为1-12 MMM: 月,显示为英文月份简写,如 Jan MMMM: 月,显示为英文月份全称,如 Janualy dd: 日,2位数表示,如02 d: 日,1-2位显示,如 2 EEE: 简写星期几,如Sun EEEE: 全写星期几,如Sunday aa: 上下午,AM/PM H: 时,24小时制,0-23 K:时,12小时制,0-11 m: 分,1-2位 mm: 分,2位 s: 秒,1-2位 ss: 秒,2位 S: 毫秒 获取一个类的所有子类 + (NSArray *) allSubclasses { Class myClass = [self class]; NSMutableArray *mySubclasses = [NSMutableArray array]; unsigned int numOfClasses; Class *classes = objc_copyClassList(&numOfClasses;); for (unsigned int ci = 0; ci 监测IOS设备是否设置了代理,需要CFNetwork.framework NSDictionary *proxySettings = (__bridge NSDictionary *)(CFNetworkCopySystemProxySettings()); NSArray *proxies = (__bridge NSArray *)(CFNetworkCopyProxiesForURL((__bridge CFURLRef _Nonnull)([NSURLURLWithString:@"http://www.baidu.com"]), (__bridge CFDictionaryRef _Nonnull)(proxySettings))); NSLog(@"\n%@",proxies); NSDictionary *settings = proxies[0]; NSLog(@"%@",[settings objectForKey:(NSString *)kCFProxyHostNameKey]); NSLog(@"%@",[settings objectForKey:(NSString *)kCFProxyPortNumberKey]); NSLog(@"%@",[settings objectForKey:(NSString *)kCFProxyTypeKey]); if ([[settings objectForKey:(NSString *)kCFProxyTypeKey] isEqualToString:@"kCFProxyTypeNone"]) { NSLog(@"没代理"); } else { NSLog(@"设置了代理"); } 阿拉伯数字转中文格式 +(NSString *)translation:(NSString *)arebic { NSString *str = arebic; NSArray *arabic_numerals = @[@"1",@"2",@"3",@"4",@"5",@"6",@"7",@"8",@"9",@"0"]; NSArray *chinese_numerals = @[@"一",@"二",@"三",@"四",@"五",@"六",@"七",@"八",@"九",@"零"]; NSArray *digits = @[@"个",@"十",@"百",@"千",@"万",@"十",@"百",@"千",@"亿",@"十",@"百",@"千",@"兆"]; NSDictionary *dictionary = [NSDictionary dictionaryWithObjects:chinese_numerals forKeys:arabic_numerals]; NSMutableArray *sums = [NSMutableArray array]; for (int i = 0; i Base64编码与NSString对象或NSData对象的转换 // Create NSData object NSData *nsdata = http://www.mamicode.com/[@"iOS Developer Tips encoded in Base64" dataUsingEncoding:NSUTF8StringEncoding]; // Get NSString from NSData object in Base64 NSString *base64Encoded = [nsdata base64EncodedStringWithOptions:0]; // Print the Base64 encoded string NSLog(@"Encoded: %@", base64Encoded); // Let‘s go the other way... // NSData from the Base64 encoded str NSData *nsdataFromBase64String = [[NSData alloc] initWithBase64EncodedString:base64Encoded options:0]; // Decoded NSString from the NSData NSString *base64Decoded = [[NSString alloc] initWithData:nsdataFromBase64String encoding:NSUTF8StringEncoding]; NSLog(@"Decoded: %@", base64Decoded); 取消UICollectionView的隐式动画 UICollectionView在reloadItems的时候,默认会附加一个隐式的fade动画,有时候很讨厌,尤其是当你的cell是复合cell的情况下(比如cell使用到了UIStackView)。 下面几种方法都可以帮你去除这些动画 //方法一 [UIView performWithoutAnimation:^{ [collectionView reloadItemsAtIndexPaths:@[[NSIndexPath indexPathForItem:index inSection:0]]]; }]; //方法二 [UIView animateWithDuration:0 animations:^{ [collectionView performBatchUpdates:^{ [collectionView reloadItemsAtIndexPaths:@[[NSIndexPath indexPathForItem:index inSection:0]]]; } completion:nil]; }]; //方法三 [UIView setAnimationsEnabled:NO]; [self.trackPanel performBatchUpdates:^{ [collectionView reloadItemsAtIndexPaths:@[[NSIndexPath indexPathForItem:index inSection:0]]]; } completion:^(BOOL finished) { [UIView setAnimationsEnabled:YES]; }]; 让Xcode的控制台支持LLDB类型的打印 打开终端输入三条命令: touch ~/.lldbinit echo display @import UIKit >> ~/.lldbinit echo target stop-hook add -o \"target stop-hook disable\" >> ~/.lldbinit CocoaPods pod install/pod update更新慢的问题 pod install --verbose --no-repo-update pod update --verbose --no-repo-update 如果不加后面的参数,默认会升级CocoaPods的spec仓库,加一个参数可以省略这一步,然后速度就会提升不少 UIImage 占用内存大小 UIImage *image = [UIImage imageNamed:@"aa"]; NSUInteger size = CGImageGetHeight(image.CGImage) * CGImageGetBytesPerRow(image.CGImage); GCD timer定时器 dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0); dispatch_source_t timer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0,queue); dispatch_source_set_timer(timer,dispatch_walltime(NULL, 0),1.0*NSEC_PER_SEC, 0); //每秒执行 dispatch_source_set_event_handler(timer, ^{ //@"倒计时结束,关闭" dispatch_source_cancel(timer); dispatch_async(dispatch_get_main_queue(), ^{ }); }); dispatch_resume(timer);
在这里总结一些iOS开发中的小技巧,能大大方便我们的开发,持续更新。
声明:以上内容来自用户投稿及互联网公开渠道收集整理发布,本网站不拥有所有权,未作人工编辑处理,也不承担相关法律责任,若内容有误或涉及侵权可进行投诉: 投诉/举报 工作人员会在5个工作日内联系你,一经查实,本站将立刻删除涉嫌侵权内容。