值得收藏的iOS开发常用代码块

遍历可变数组的同时删除数组元素

NSMutableArray *copyArray = [NSMutableArray arrayWithArray:array];NSString *str1 = @“zhangsan”; for （AddressPerson *perName in copyArray） { if （[[perName name] isEqualToString:str1]） { [array removeObject:perName]; } }

获取系统当前语言

NSString *currentLanguage = [[NSLocale preferredLanguages] objectAtIndex:0];NSLog（@"currentlanguage = %@",currentLanguage）;if （[currentLanguage containsString:@"zh-Hans"]） {NSLog（@"zh-Hans简体中文"）;}else if （[currentLanguage containsString:@"zh-Hant"]） {NSLog（@"zh-Hant繁体中文"）;}

UITableView的Group样式下顶部空白处理

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<=sectionHeaderHeight&&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）;}}

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

void enumerateFonts（）{for（NSString *familyName in [UIFont familyNames]）{NSLog（@"%@",familyName）;NSArray *fontNames = [UIFont fontNamesForFamilyName:familyName];for（NSString *fontName in fontNames）{NSLog（@"	|- %@",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 = CGBitmapContextGetData （cgctx）;if （data ！= NULL） {int offset = 4*（（w*round（point.y））+round（point.x））;int alpha = data[offset];int red = data[offset+1];int green = data[offset+2];int blue = data[offset+3];color = [UIColor colorWithRed:（red/255.0f） green:（green/255.0f） blue: （blue/255.0f） alpha:（alpha/255.0f）];}CGContextRelease（cgctx）;if （data） {free（data）;}return color;}

字符串反转

//第一种：- （NSString *）reverseWordsInString:（NSString *）str{NSMutableString *newString = [[NSMutableString alloc] initWithCapacity:str.length];for （NSInteger i = str.length - 1; i >= 0 ; i --）{unichar ch = [str characterAtIndex:i];[newString appendFormat:@"%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

//第一种[UIApplication sharedApplication].idleTimerDisabled = YES;//第二种[[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];

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"]];

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

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） && [viewOrientation isEqualToString: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
%f
%f
%f",sum,avg,max,min）;

修改UITextField中Placeholder的文字颜色
[textField setValue:[UIColor redColor] forKeyPath:@"_placeholderLabel.textColor"];
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 < numOfClasses; ci++）{Class superClass = classes[ci];do{superClass = class_getSuperclass（superClass）;} while （superClass && superClass ！= myClass）;if （superClass）{[mySubclasses addObject: classes[ci]];}}free（classes）;return mySubclasses;}

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 < str.length; i ++） {NSString *substr = [str substringWithRange:NSMakeRange（i, 1）];NSString *a = [dictionary objectForKey:substr];NSString *b = digits[str.length -i-1];NSString *sum = [a stringByAppendingString:b];if （[a isEqualToString:chinese_numerals[9]]）{if（[b isEqualToString:digits[4]] || [b isEqualToString:digits[8]]）{sum = b;if （[[sums lastObject] isEqualToString:chinese_numerals[9]]）{[sums removeLastObject];}}else{sum = chinese_numerals[9];}if （[[sums lastObject] isEqualToString:sum]）{continue;}}[sums addObject:sum];}NSString *sumStr = [sums componentsJoinedByString:@""];NSString *chinese = [sumStr substringToIndex:sumStr.length-1];NSLog（@"%@",str）;NSLog（@"%@",chinese）;return chinese;}

取消UICollectionView的隐式动画

//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];}];

判断邮箱格式是否正确的代码

-（BOOL）isValidateEmail:（NSString *）email  {  NSString *emailRegex = @"[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\.[A-Za-z]{2,4}";  NSPredicate *emailTest = [NSPredicate predicateWithFormat:@"SELF MATCHES%@",emailRegex];  return [emailTest evaluateWithObject:email];  }

iOS中UITextField的字数限制

//在viewDidLoad中注册<UITextFieldTextDidChangeNotification>通知[[NSNotificationCenter defaultCenter]addObserver:self selector:@selector（textFiledEditChanged:）name:@"UITextFieldTextDidChangeNotification" object:myTextField];//实现监听方法#pragma mark - Notification Method-（void）textFieldEditChanged:（NSNotification *）obj{UITextField *textField = （UITextField *）obj.object;NSString *toBeString = textField.text;//获取高亮部分UITextRange *selectedRange = [textField markedTextRange];UITextPosition *position = [textField positionFromPosition:selectedRange.start offset:0];// 没有高亮选择的字，则对已输入的文字进行字数统计和限制if （！position）{if （toBeString.length > MAX_STARWORDS_LENGTH）{NSRange rangeIndex = [toBeString rangeOfComposedCharacterSequenceAtIndex:MAX_STARWORDS_LENGTH];if （rangeIndex.length == 1）{textField.text = [toBeString substringToIndex:MAX_STARWORDS_LENGTH];}else{NSRange rangeRange = [toBeString rangeOfComposedCharacterSequencesForRange:NSMakeRange（0, MAX_STARWORDS_LENGTH）];textField.text = [toBeString substringWithRange:rangeRange];}}}}

小伙伴们，今天就分享到这里，下期更精彩！