转载：多年iOS开发经验总结(二)

转载地址：http://www.jianshu.com/p/9fcd37c0ea05

 

1、设置UILabel行间距

NSMutableAttributedString* attrString = [[NSMutableAttributedString alloc] initWithString:label.text]; NSMutableParagraphStyle *style = [[NSMutableParagraphStyle alloc] init]; [style setLineSpacing:20]; [attrString addAttribute:NSParagraphStyleAttributeName value:style range:NSMakeRange(0, label.text.length)]; label.attributedText = attrString;

// 或者使用xib，看下gif图

Untitled.gif

2、当使用-performSelector:withObject:withObject:afterDelay:方法时，需要传入多参数问题

// 方法一、 // 把参数放进一个数组／字典，直接把数组／字典当成一个参数传过去，具体方法实现的地方再解析这个数组／字典 NSArray * array = [NSArray arrayWithObjects: @"first", @"second", nil]; [self performSelector:@selector(fooFirstInput:) withObject: array afterDelay:15.0]; // 方法二、 // 使用NSInvocation SEL aSelector = NSSelectorFromString(@"doSoming:argument2:"); NSInteger argument1 = 10; NSString *argument2 = @"argument2"; if([self respondsToSelector:aSelector]) { NSInvocation *inv = [NSInvocation invocationWithMethodSignature:[self methodSignatureForSelector:aSelector]]; [inv setSelector:aSelector]; [inv setTarget:self]; [inv setArgument:&(argument1) atIndex:2]; [inv setArgument:&(argument2) atIndex:3]; [inv performSelector:@selector(invoke) withObject:nil afterDelay:15.0]; }

3、UILabel显示不同颜色字体

NSMutableAttributedString * string = [[NSMutableAttributedString alloc] initWithString:label.text]; [string addAttribute:NSForegroundColorAttributeName value:[UIColor redColor] range:NSMakeRange(0,5)]; [string addAttribute:NSForegroundColorAttributeName value:[UIColor greenColor] range:NSMakeRange(5,6)]; [string addAttribute:NSForegroundColorAttributeName value:[UIColor blueColor] range:NSMakeRange(11,5)]; label.attributedText = string;

4、比较两个CGRect/CGSize/CGPoint是否相等

if (CGRectEqualToRect(rect1, rect2)) { // 两个区域相等 // do some } if (CGPointEqualToPoint(point1, point2)) { // 两个点相等 // do some } if (CGSizeEqualToSize(size1, size2)) { // 两个size相等 // do some }

5、比较两个NSDate相差多少小时

NSDate* date1 = someDate; NSDate* date2 = someOtherDate; NSTimeInterval distanceBetweenDates = [date1 timeIntervalSinceDate:date2]; double secondsInAnHour = 3600; // 除以3600是把秒化成小时，除以60得到结果为相差的分钟数 NSInteger hoursBetweenDates = distanceBetweenDates / secondsInAnHour;

6、每个cell之间增加间距

// 方法一，每个分区只显示一行cell，分区头当作你想要的间距(注意，从数据源数组中取值的时候需要用indexPath.section而不是indexPath.row) - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView { return yourArry.count; } - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { return 1; } -(CGFloat)tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section { return cellSpacingHeight; } // 方法二，在cell的contentView上加个稍微低一点的view，cell上原本的内容放在你的view上，而不是contentView上，这样能伪造出一个间距来。 // 方法三，自定义cell，重写setFrame：方法 - (void)setFrame:(CGRect)frame { frame.size.height -= 20; [super setFrame:frame]; }

7、播放一张张连续的图片

// 加入现在有三张图片分别为animate_1、animate_2、animate_3 // 方法一 imageView.animationImages = @[[UIImage imageNamed:@"animate_1"], [UIImage imageNamed:@"animate_2"], [UIImage imageNamed:@"animate_3"]]; imageView.animationDuration = 1.0; // 方法二 imageView.image = [UIImage animatedImageNamed:@"animate_" duration:1.0]; // 方法二解释下，这个方法会加载animate_为前缀的，后边0-1024，也就是animate_0、animate_1一直到animate_1024

8、加载gif图片

推荐使用这个框架 FLAnimatedImage

9、防止离屏渲染为image添加圆角

// image分类 - (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; }

10、查看系统所有字体

// 打印字体 for (id familyName in [UIFont familyNames]) { NSLog(@"%@", familyName); for (id fontName in [UIFont fontNamesForFamilyName:familyName]) NSLog(@" %@", fontName); } // 也可以进入这个网址查看 http://iosfonts.com/

11、获取随机数

NSInteger i = arc4random();

12、获取随机数小数(0-1之间)

#define ARC4RANDOM_MAX 0x100000000 double val = ((double)arc4random() / ARC4RANDOM_MAX);

13、AVPlayer视频播放完成的通知监听

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(videoPlayEnd) name:AVPlayerItemDidPlayToEndTimeNotification object:nil];

14、判断两个rect是否有交叉

if (CGRectIntersectsRect(rect1, rect2)) { }

15、判断一个字符串是否为数字

NSCharacterSet *notDigits = [[NSCharacterSet decimalDigitCharacterSet] invertedSet]; if ([str rangeOfCharacterFromSet:notDigits].location == NSNotFound) { // 是数字 } else { // 不是数字 }

16、将一个view保存为pdf格式

- (void)createPDFfromUIView:(UIView*)aView saveToDocumentsWithFileName:(NSString*)aFilename { NSMutableData *pdfData = [NSMutableData data]; UIGraphicsBeginPDFContextToData(pdfData, aView.bounds, nil); UIGraphicsBeginPDFPage(); CGContextRef pdfContext = UIGraphicsGetCurrentContext(); [aView.layer renderInContext:pdfContext]; UIGraphicsEndPDFContext(); NSArray* documentDirectories = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask,YES); NSString* documentDirectory = [documentDirectories objectAtIndex:0]; NSString* documentDirectoryFilename = [documentDirectory stringByAppendingPathComponent:aFilename]; [pdfData writeToFile:documentDirectoryFilename atomically:YES]; NSLog(@"documentDirectoryFileName: %@",documentDirectoryFilename); }

17、让一个view在父视图中心

child.center = [parent convertPoint:parent.center fromView:parent.superview];

18、获取当前导航控制器下前一个控制器

- (UIViewController *)backViewController { NSInteger myIndex = [self.navigationController.viewControllers indexOfObject:self]; if ( myIndex != 0 && myIndex != NSNotFound ) { return [self.navigationController.viewControllers objectAtIndex:myIndex-1]; } else { return nil; } }

19、保存UIImage到本地

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); NSString *filePath = [[paths objectAtIndex:0] stringByAppendingPathComponent:@"Image.png"]; [UIImagePNGRepresentation(image) writeToFile:filePath atomically:YES];

20、键盘上方增加工具栏

UIToolbar *keyboardDoneButtonView = [[UIToolbar alloc] init]; [keyboardDoneButtonView sizeToFit]; UIBarButtonItem *doneButton = [[UIBarButtonItem alloc] initWithTitle:@"Done" style:UIBarButtonItemStyleBordered target:self action:@selector(doneClicked:)]; [keyboardDoneButtonView setItems:[NSArray arrayWithObjects:doneButton, nil]]; txtField.inputAccessoryView = keyboardDoneButtonView;

21、copy一个view

因为UIView没有实现copy协议，因此找不到copyWithZone方法，使用copy的时候导致崩溃但是我们可以通过归档再解档实现copy，这相当于对视图进行了一次深拷贝，代码如下

id copyOfView = [NSKeyedUnarchiver unarchiveObjectWithData:[NSKeyedArchiver archivedDataWithRootObject:originalView]];

22、在image上绘制文字并生成新的image

UIFont *font = [UIFont boldSystemFontOfSize:12]; UIGraphicsBeginImageContext(image.size); [image drawInRect:CGRectMake(0,0,image.size.width,image.size.height)]; CGRect rect = CGRectMake(point.x, point.y, image.size.width, image.size.height); [[UIColor whiteColor] set]; [text drawInRect:CGRectIntegral(rect) withFont:font]; UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext();

23、判断一个view是否为另一个view的子视图

// 如果myView是self.view本身，也会返回yes BOOL isSubView = [myView isDescendantOfView:self.view];

24、判断一个字符串是否包含另一个字符串

// 方法一、这种方法只适用于iOS8之后，如果是配iOS8之前用方法二 if ([str containsString:otherStr]) NSLog(@"包含"); // 方法二 NSRange range = [str rangeOfString:otherStr]; if (range.location != NSNotFound) NSLog(@"包含");

25、UICollectionView自动滚动到某行

// 重写viewDidLayoutSubviews方法 -(void)viewDidLayoutSubviews { [super viewDidLayoutSubviews]; [self.collectionView scrollToItemAtIndexPath:indexPath atScrollPosition:UICollectionViewScrollPositionCenteredVertically animated:NO]; }

26、修改系统UIAlertController

// 但是据说这种方法会被App Store拒绝(慎用！) UIAlertController *alertVC = [UIAlertController alertControllerWithTitle:@"" message:@"" preferredStyle:UIAlertControllerStyleActionSheet]; NSMutableAttributedString *hogan = [[NSMutableAttributedString alloc] initWithString:@"我是一个大文本"]; [hogan addAttribute:NSFontAttributeName value:[UIFont systemFontOfSize:30] range:NSMakeRange(4, 1)]; [hogan addAttribute:NSForegroundColorAttributeName value:[UIColor redColor] range:NSMakeRange(4, 1)]; [alertVC setValue:hogan forKey:@"attributedTitle"]; UIAlertAction *button = [UIAlertAction actionWithTitle:@"Label text" style:UIAlertActionStyleDefault handler:^(UIAlertAction *action){ }]; UIImage *accessoryImage = [UIImage imageNamed:@"1"]; [button setValue:accessoryImage forKey:@"image"]; [alertVC addAction:button]; [self presentViewController:alertVC animated:YES completion:nil];

27、判断某一行的cell是否已经显示

CGRect cellRect = [tableView rectForRowAtIndexPath:indexPath]; BOOL completelyVisible = CGRectContainsRect(tableView.bounds, cellRect);

28、让导航控制器pop回指定的控制器

NSMutableArray *allViewControllers = [NSMutableArray arrayWithArray:[self.navigationController viewControllers]]; for (UIViewController *aViewController in allViewControllers) { if ([aViewController isKindOfClass:[RequiredViewController class]]) { [self.navigationController popToViewController:aViewController animated:NO]; } }

29、动画修改label上的文字

// 方法一 CATransition *animation = [CATransition animation]; animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut]; animation.type = kCATransitionFade; animation.duration = 0.75; [self.label.layer addAnimation:animation forKey:@"kCATransitionFade"]; self.label.text = @"New"; // 方法二 [UIView transitionWithView:self.label duration:0.25f options:UIViewAnimationOptionTransitionCrossDissolve animations:^{ self.label.text = @"Well done!"; } completion:nil]; // 方法三 [UIView animateWithDuration:1.0 animations:^{ self.label.alpha = 0.0f; self.label.text = @"newText"; self.label.alpha = 1.0f; }];

30、判断字典中是否包含某个key值

if ([dic objectForKey:@"yourKey"]) { NSLog(@"有这个值"); } else { NSLog(@"没有这个值"); }

31、获取屏幕方向

UIInterfaceOrientation orientation = [UIApplication sharedApplication].statusBarOrientation; if(orientation == 0) //Default orientation //默认 else if(orientation == UIInterfaceOrientationPortrait) //竖屏 else if(orientation == UIInterfaceOrientationLandscapeLeft) // 左横屏 else if(orientation == UIInterfaceOrientationLandscapeRight) //右横屏

32、设置UIImage的透明度

// 方法一、添加UIImage分类 - (UIImage *)imageByApplyingAlpha:(CGFloat) alpha { UIGraphicsBeginImageContextWithOptions(self.size, NO, 0.0f); CGContextRef ctx = UIGraphicsGetCurrentContext(); CGRect area = CGRectMake(0, 0, self.size.width, self.size.height); CGContextScaleCTM(ctx, 1, -1); CGContextTranslateCTM(ctx, 0, -area.size.height); CGContextSetBlendMode(ctx, kCGBlendModeMultiply); CGContextSetAlpha(ctx, alpha); CGContextDrawImage(ctx, area, self.CGImage); UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); return newImage; } // 方法二、如果没有奇葩需求，干脆用UIImageView设置透明度 UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageWithName:@"yourImage"]]; imageView.alpha = 0.5;

33、Attempt to mutate immutable object with insertString:atIndex:

这个错是因为你拿字符串调用insertString:atIndex:方法的时候，调用对象不是NSMutableString，应该先转成这个类型再调用

34、UIWebView添加单击手势不响应

UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(webViewClick)]; tap.delegate = self; [_webView addGestureRecognizer:tap]; // 因为webView本身有一个单击手势，所以再添加会造成手势冲突，从而不响应。需要绑定手势代理，并实现下边的代理方法 - (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer{ return YES; }

35、获取手机RAM容量

// 需要导入#import <mach/mach.h> mach_port_t host_port; mach_msg_type_number_t host_size; vm_size_t pagesize; host_port = mach_host_self(); host_size = sizeof(vm_statistics_data_t) / sizeof(integer_t); host_page_size(host_port, &pagesize); vm_statistics_data_t vm_stat; if (host_statistics(host_port, HOST_VM_INFO, (host_info_t)&vm_stat, &host_size) != KERN_SUCCESS) { NSLog(@"Failed to fetch vm statistics"); } /* Stats in bytes */ natural_t mem_used = (vm_stat.active_count + vm_stat.inactive_count + vm_stat.wire_count) * pagesize; natural_t mem_free = vm_stat.free_count * pagesize; natural_t mem_total = mem_used + mem_free; NSLog(@"已用: %u 可用: %u 总共: %u", mem_used, mem_free, mem_total);

36、地图上两个点之间的实际距离

// 需要导入#import <CoreLocation/CoreLocation.h> CLLocation *locA = [[CLLocation alloc] initWithLatitude:34 longitude:113]; CLLocation *locB = [[CLLocation alloc] initWithLatitude:31.05 longitude:121.76]; // CLLocationDistance求出的单位为米 CLLocationDistance distance = [locA distanceFromLocation:locB];

37、在应用中打开设置的某个界面

// 打开设置->通用 [[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"prefs:root=General"]]; // 以下是设置其他界面 prefs:root=General&path=About prefs:root=General&path=ACCESSIBILITY prefs:root=AIRPLANE_MODE prefs:root=General&path=AUTOLOCK prefs:root=General&path=USAGE/CELLULAR_USAGE prefs:root=Brightness prefs:root=Bluetooth prefs:root=General&path=DATE_AND_TIME prefs:root=FACETIME prefs:root=General prefs:root=General&path=Keyboard prefs:root=CASTLE prefs:root=CASTLE&path=STORAGE_AND_BACKUP prefs:root=General&path=INTERNATIONAL prefs:root=LOCATION_SERVICES prefs:root=ACCOUNT_SETTINGS prefs:root=MUSIC prefs:root=MUSIC&path=EQ prefs:root=MUSIC&path=VolumeLimit prefs:root=General&path=Network prefs:root=NIKE_PLUS_IPOD prefs:root=NOTES prefs:root=NOTIFICATIONS_ID prefs:root=Phone prefs:root=Photos prefs:root=General&path=ManagedConfigurationList prefs:root=General&path=Reset prefs:root=Sounds&path=Ringtone prefs:root=Safari prefs:root=General&path=Assistant prefs:root=Sounds prefs:root=General&path=SOFTWARE_UPDATE_LINK prefs:root=STORE prefs:root=TWITTER prefs:root=FACEBOOK prefs:root=General&path=USAGE prefs:root=VIDEO prefs:root=General&path=Network/VPN prefs:root=Wallpaper prefs:root=WIFI prefs:root=INTERNET_TETHERING prefs:root=Phone&path=Blocked prefs:root=DO_NOT_DISTURB

38、在UITextView中显示html文本

UITextView *textView = [[UITextView alloc] initWithFrame:CGRectMake(20, 30, 100, 199)]; textView.backgroundColor = [UIColor redColor]; [self.view addSubview:textView]; NSString *htmlString = @"<h1>Header</h1><h2>Subheader</h2><p>Some <em>text</em></p>"; NSAttributedString *attributedString = [[NSAttributedString alloc] initWithData: [htmlString dataUsingEncoding:NSUnicodeStringEncoding] options: @{ NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType } documentAttributes: nil error: nil]; textView.attributedText = attributedString;

39、监听scrollView是否滚动到了顶部／底部

-(void)scrollViewDidScroll: (UIScrollView*)scrollView { float scrollViewHeight = scrollView.frame.size.height; float scrollContentSizeHeight = scrollView.contentSize.height; float scrollOffset = scrollView.contentOffset.y; if (scrollOffset == 0) { // 滚动到了顶部 } else if (scrollOffset + scrollViewHeight == scrollContentSizeHeight) { // 滚动到了底部 } }

40、UISlider增量／减量为固定值(假如为5)

- (void)setupSlider { UISlider *slider = [[UISlider alloc] init]; [self.view addSubview:slider]; [slider addTarget:self action:@selector(sliderAction:) forControlEvents:UIControlEventValueChanged]; slider.maximumValue = 100; slider.minimumValue = 0; slider.frame = CGRectMake(200, 20, 100, 30); } - (void)sliderAction:(UISlider *)slider { [slider setValue:((int)((slider.value + 2.5) / 5) * 5) animated:NO]; }

41、选中textField或者textView所有文本(我这里以textView为例)

[self.textView setSelectedTextRange:[self.textView textRangeFromPosition:self.textView.beginningOfDocument toPosition:self.textView.endOfDocument]]

42、从导航控制器中删除某个控制器

// 方法一、知道这个控制器所处的导航控制器下标 NSMutableArray *navigationArray = [[NSMutableArray alloc] initWithArray: self.navigationController.viewControllers]; [navigationArray removeObjectAtIndex: 2]; self.navigationController.viewControllers = navigationArray; // 方法二、知道具体是哪个控制器 NSArray* tempVCA = [self.navigationController viewControllers]; for(UIViewController *tempVC in tempVCA) { if([tempVC isKindOfClass:[urViewControllerClass class]]) { [tempVC removeFromParentViewController]; } }

43、隐藏UITextView/UITextField光标

textField.tintColor = [UIColor clearColor];

44、当UITextView/UITextField中没有文字时，禁用回车键

textField.enablesReturnKeyAutomatically = YES;

45、字符串encode编码(编码url字符串不成功的问题)

// 我们一般用这个方法处理stringByAddingPercentEscapesUsingEncoding但是这个方法好想不会处理／和&这种特殊符号，这种情况就需要用下边这个方法处理 @implementation NSString (NSString_Extended) - (NSString *)urlencode { NSMutableString *output = [NSMutableString string]; const unsigned char *source = (const unsigned char *)[self UTF8String]; int sourceLen = strlen((const char *)source); for (int i = 0; i < sourceLen; ++i) { const unsigned char thisChar = source[i]; if (thisChar == ' '){ [output appendString:@"+"]; } else if (thisChar == '.' || thisChar == '-' || thisChar == '_' || thisChar == '~' || (thisChar >= 'a' && thisChar <= 'z') || (thisChar >= 'A' && thisChar <= 'Z') || (thisChar >= '0' && thisChar <= '9')) { [output appendFormat:@"%c", thisChar]; } else { [output appendFormat:@"%%X", thisChar]; } } return output; }

46、计算UILabel上某段文字的frame

@implementation UILabel (TextRect) - (CGRect)boundingRectForCharacterRange:(NSRange)range { NSTextStorage *textStorage = [[NSTextStorage alloc] initWithAttributedString:[self attributedText]]; NSLayoutManager *layoutManager = [[NSLayoutManager alloc] init]; [textStorage addLayoutManager:layoutManager]; NSTextContainer *textContainer = [[NSTextContainer alloc] initWithSize:[self bounds].size]; textContainer.lineFragmentPadding = 0; [layoutManager addTextContainer:textContainer]; NSRange glyphRange; [layoutManager characterRangeForGlyphRange:range actualGlyphRange:&glyphRange]; return [layoutManager boundingRectForGlyphRange:glyphRange inTextContainer:textContainer]; }

47、获取随机UUID

NSString *result; if([[[UIDevice currentDevice] systemVersion] floatValue] > 6.0) { result = [[NSUUID UUID] UUIDString]; } else { CFUUIDRef uuidRef = CFUUIDCreate(NULL); CFStringRef uuid = CFUUIDCreateString(NULL, uuidRef); CFRelease(uuidRef); result = (__bridge_transfer NSString *)uuid; }

48、仿苹果抖动动画

#define RADIANS(degrees) (((degrees) * M_PI) / 180.0) - (void)startAnimate { view.transform = CGAffineTransformRotate(CGAffineTransformIdentity, RADIANS(-5)); [UIView animateWithDuration:0.25 delay:0.0 options:(UIViewAnimationOptionAllowUserInteraction | UIViewAnimationOptionRepeat | UIViewAnimationOptionAutoreverse) animations:^ { view.transform = CGAffineTransformRotate(CGAffineTransformIdentity, RADIANS(5)); } completion:nil]; } - (void)stopAnimate { [UIView animateWithDuration:0.25 delay:0.0 options:(UIViewAnimationOptionAllowUserInteraction | UIViewAnimationOptionBeginFromCurrentState | UIViewAnimationOptionCurveLinear) animations:^ { view.transform = CGAffineTransformIdentity; } completion:nil]; }

49、修改UISearBar内部背景颜色

UITextField *textField = [_searchBar valueForKey:@"_searchField"]; textField.backgroundColor = [UIColor redColor];

50、UITextView滚动到顶部

// 方法一 [self.textView scrollRangeToVisible:NSMakeRange(0, 0)]; // 方法二 [self.textView setContentOffset:CGPointZero animated:YES];

51、通知监听APP生命周期

UIApplicationDidEnterBackgroundNotification 应用程序进入后台UIApplicationWillEnterForegroundNotification 应用程序将要进入前台UIApplicationDidFinishLaunchingNotification 应用程序完成启动UIApplicationDidFinishLaunchingNotification 应用程序由挂起变的活跃UIApplicationWillResignActiveNotification 应用程序挂起(有电话进来或者锁屏)UIApplicationDidReceiveMemoryWarningNotification 应用程序收到内存警告UIApplicationDidReceiveMemoryWarningNotification 应用程序终止(后台杀死、手机关机等)UIApplicationSignificantTimeChangeNotification 当有重大时间改变(凌晨0点，设备时间被修改，时区改变等)UIApplicationWillChangeStatusBarOrientationNotification 设备方向将要改变UIApplicationDidChangeStatusBarOrientationNotification 设备方向改变UIApplicationWillChangeStatusBarFrameNotification 设备状态栏frame将要改变UIApplicationDidChangeStatusBarFrameNotification 设备状态栏frame改变UIApplicationBackgroundRefreshStatusDidChangeNotification 应用程序在后台下载内容的状态发生变化UIApplicationProtectedDataWillBecomeUnavailable 本地受保护的文件被锁定,无法访问UIApplicationProtectedDataWillBecomeUnavailable 本地受保护的文件可用了

52、触摸事件类型

UIControlEventTouchCancel 取消控件当前触发的事件UIControlEventTouchDown 点按下去的事件UIControlEventTouchDownRepeat 重复的触动事件UIControlEventTouchDragEnter 手指被拖动到控件的边界的事件UIControlEventTouchDragExit 一个手指从控件内拖到外界的事件UIControlEventTouchDragInside 手指在控件的边界内拖动的事件UIControlEventTouchDragOutside 手指在控件边界之外被拖动的事件UIControlEventTouchUpInside 手指处于控制范围内的触摸事件UIControlEventTouchUpOutside 手指超出控制范围的控制中的触摸事件

53、UITextField文字周围增加边距

// 子类化UITextField，增加insert属性 @interface WZBTextField : UITextField @property (nonatomic, assign) UIEdgeInsets insets; @end // 在.m文件重写下列方法 - (CGRect)textRectForBounds:(CGRect)bounds { CGRect paddedRect = UIEdgeInsetsInsetRect(bounds, self.insets); if (self.rightViewMode == UITextFieldViewModeAlways || self.rightViewMode == UITextFieldViewModeUnlessEditing) { return [self adjustRectWithWidthRightView:paddedRect]; } return paddedRect; } - (CGRect)placeholderRectForBounds:(CGRect)bounds { CGRect paddedRect = UIEdgeInsetsInsetRect(bounds, self.insets); if (self.rightViewMode == UITextFieldViewModeAlways || self.rightViewMode == UITextFieldViewModeUnlessEditing) { return [self adjustRectWithWidthRightView:paddedRect]; } return paddedRect; } - (CGRect)editingRectForBounds:(CGRect)bounds { CGRect paddedRect = UIEdgeInsetsInsetRect(bounds, self.insets); if (self.rightViewMode == UITextFieldViewModeAlways || self.rightViewMode == UITextFieldViewModeWhileEditing) { return [self adjustRectWithWidthRightView:paddedRect]; } return paddedRect; } - (CGRect)adjustRectWithWidthRightView:(CGRect)bounds { CGRect paddedRect = bounds; paddedRect.size.width -= CGRectGetWidth(self.rightView.frame); return paddedRect; }

54、监听UISlider拖动状态

// 添加事件 [slider addTarget:self action:@selector(sliderValurChanged:forEvent:) forControlEvents:UIControlEventValueChanged]; // 实现方法 - (void)sliderValurChanged:(UISlider*)slider forEvent:(UIEvent*)event { UITouch *touchEvent = [[event allTouches] anyObject]; switch (touchEvent.phase) { case UITouchPhaseBegan: NSLog(@"开始拖动"); break; case UITouchPhaseMoved: NSLog(@"正在拖动"); break; case UITouchPhaseEnded: NSLog(@"结束拖动"); break; default: break; } }

55、设置UITextField光标位置

// textField需要设置的textField，index要设置的光标位置 - (void)cursorLocation:(UITextField *)textField index:(NSInteger)index { NSRange range = NSMakeRange(index, 0); UITextPosition *start = [textField positionFromPosition:[textField beginningOfDocument] offset:range.location]; UITextPosition *end = [textField positionFromPosition:start offset:range.length]; [textField setSelectedTextRange:[textField textRangeFromPosition:start toPosition:end]]; }

56、去除webView底部黑色

[webView setBackgroundColor:[UIColor clearColor]]; [webView setOpaque:NO]; for (UIView *v1 in [webView subviews]) { if ([v1 isKindOfClass:[UIScrollView class]]) { for (UIView *v2 in v1.subviews) { if ([v2 isKindOfClass:[UIImageView class]]) { v2.hidden = YES; } } } }

57、获取collectionViewCell在屏幕中的frame

UICollectionViewLayoutAttributes *attributes = [collectionView layoutAttributesForItemAtIndexPath:indexPath]; CGRect cellRect = attributes.frame; CGRect cellFrameInSuperview = [collectionView convertRect:cellRect toView:[cv superview]];

58、比较两个UIImage是否相等

- (BOOL)image:(UIImage *)image1 isEqualTo:(UIImage *)image2 { NSData *data1 = UIImagePNGRepresentation(image1); NSData *data2 = UIImagePNGRepresentation(image2); return [data1 isEqual:data2]; }

59、解决当UIScrollView上有UIButton的时候，触摸到button滑动不了的问题

// 子类化UIScrollView，并重写以下方法 - (instancetype)initWithFrame:(CGRect)frame { if (self = [super initWithFrame:frame]) { self.delaysContentTouches = NO; } return self; } - (BOOL)touchesShouldCancelInContentView:(UIView *)view { if ([view isKindOfClass:UIButton.class]) { return YES; } return [super touchesShouldCancelInContentView:view]; }

60、UITextView中的文字添加阴影效果

- (void)setTextLayer:(UITextView *)textView color:(UIColor *)color { CALayer *textLayer = ((CALayer *)[textView.layer.sublayers objectAtIndex:0]); textLayer.shadowColor = color.CGColor; textLayer.shadowOffset = CGSizeMake(0.0f, 1.0f); textLayer.shadowOpacity = 1.0f; textLayer.shadowRadius = 1.0f; }

61、MD5加密

+ (NSString *)md5:(NSString *)str { const char *concat_str = [str UTF8String]; unsigned char result[CC_MD5_DIGEST_LENGTH]; CC_MD5(concat_str, (unsigned int)strlen(concat_str), result); NSMutableString *hash = [NSMutableString string]; for (int i =0; i <16; i++){ [hash appendFormat:@"X", result[i]]; } return [hash uppercaseString]; }

62、base64加密

@interface NSData (Base64) /** * @brief 字符串base64后转data */ + (NSData *)dataWithBase64EncodedString:(NSString *)string { if (![string length]) return nil; NSData *decoded = nil; #if __MAC_OS_X_VERSION_MIN_REQUIRED < __MAC_10_9 || __IPHONE_OS_VERSION_MIN_REQUIRED < __IPHONE_7_0 if (![NSData instancesRespondToSelector:@selector(initWithBase64EncodedString:options:)]) { #pragma clang diagnostic push #pragma clang diagnostic ignored "-Wdeprecated-declarations" decoded = [[self alloc] initWithBase64Encoding:[string stringByReplacingOccurrencesOfString:@"[^A-Za-z0-9+/=]" withString:@"" options:NSRegularExpressionSearch range:NSMakeRange(0, [string length])]]; #pragma clang diagnostic pop } else #endif { decoded = [[self alloc] initWithBase64EncodedString:string options:NSDataBase64DecodingIgnoreUnknownCharacters]; } return [decoded length]? decoded: nil; } /** * @brief NSData转string * @param wrapWidth 换行长度 76 64 */ - (NSString *)base64EncodedStringWithWrapWidth:(NSUInteger)wrapWidth { if (![self length]) return nil; NSString *encoded = nil; #if __MAC_OS_X_VERSION_MIN_REQUIRED < __MAC_10_9 || __IPHONE_OS_VERSION_MIN_REQUIRED < __IPHONE_7_0 if (![NSData instancesRespondToSelector:@selector(base64EncodedStringWithOptions:)]) { #pragma clang diagnostic push #pragma clang diagnostic ignored "-Wdeprecated-declarations" encoded = [self base64Encoding]; #pragma clang diagnostic pop } else #endif { switch (wrapWidth) { case 64: { return [self base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength]; } case 76: { return [self base64EncodedStringWithOptions:NSDataBase64Encoding76CharacterLineLength]; } default: { encoded = [self base64EncodedStringWithOptions:(NSDataBase64EncodingOptions)0]; } } } if (!wrapWidth || wrapWidth >= [encoded length]) { return encoded; } wrapWidth = (wrapWidth / 4) * 4; NSMutableString *result = [NSMutableString string]; for (NSUInteger i = 0; i < [encoded length]; i+= wrapWidth) { if (i + wrapWidth >= [encoded length]) { [result appendString:[encoded substringFromIndex:i]]; break; } [result appendString:[encoded substringWithRange:NSMakeRange(i, wrapWidth)]]; [result appendString:@"\r\n"]; } return result; } /** * @brief NSData转string 换行长度默认64 */ - (NSString *)base64EncodedString { return [self base64EncodedStringWithWrapWidth:0]; }

63、AES加密

#import <CommonCrypto/CommonCryptor.h> @interface NSData (AES) /** * 利用AES加密数据 */ - (NSData*)encryptedWithAESUsingKey:(NSString*)key andIV:(NSData*)iv { NSData *keyData = [key dataUsingEncoding:NSUTF8StringEncoding]; size_t dataMoved; NSMutableData *encryptedData = [NSMutableData dataWithLength:self.length + kCCBlockSizeAES128]; CCCryptorStatus status = CCCrypt(kCCEncrypt,kCCAlgorithmAES128,kCCOptionPKCS7Padding,keyData.bytes,keyData.length,iv.bytes,self.bytes,self.length,encryptedData.mutableBytes, encryptedData.length,&dataMoved); if (status == kCCSuccess) { encryptedData.length = dataMoved; return encryptedData; } return nil; } /** * @brief 利用AES解密据 */ - (NSData*)decryptedWithAESUsingKey:(NSString*)key andIV:(NSData*)iv { NSData *keyData = [key dataUsingEncoding:NSUTF8StringEncoding]; size_t dataMoved; NSMutableData *decryptedData = [NSMutableData dataWithLength:self.length + kCCBlockSizeAES128]; CCCryptorStatus result = CCCrypt(kCCDecrypt,kCCAlgorithmAES128,kCCOptionPKCS7Padding,keyData.bytes,keyData.length,iv.bytes,self.bytes,self.length,decryptedData.mutableBytes, decryptedData.length,&dataMoved); if (result == kCCSuccess) { decryptedData.length = dataMoved; return decryptedData; } return nil; }

64、3DES加密

#import <CommonCrypto/CommonCryptor.h> @interface NSData (3DES) /** * 利用3DES加密数据 */ - (NSData*)encryptedWith3DESUsingKey:(NSString*)key andIV:(NSData*)iv { NSData *keyData = [key dataUsingEncoding:NSUTF8StringEncoding]; size_t dataMoved; NSMutableData *encryptedData = [NSMutableData dataWithLength:self.length + kCCBlockSize3DES]; CCCryptorStatus result = CCCrypt(kCCEncrypt,kCCAlgorithm3DES,kCCOptionPKCS7Padding,keyData.bytes,keyData.length,iv.bytes,self.bytes,self.length,encryptedData.mutableBytes,encryptedData.length,&dataMoved); if (result == kCCSuccess) { encryptedData.length = dataMoved; return encryptedData; } return nil; } /** * @brief 利用3DES解密数据 */ - (NSData*)decryptedWith3DESUsingKey:(NSString*)key andIV:(NSData*)iv { NSData *keyData = [key dataUsingEncoding:NSUTF8StringEncoding]; size_t dataMoved; NSMutableData *decryptedData = [NSMutableData dataWithLength:self.length + kCCBlockSize3DES]; CCCryptorStatus result = CCCrypt(kCCDecrypt,kCCAlgorithm3DES,kCCOptionPKCS7Padding,keyData.bytes,keyData.length,iv.bytes,self.bytes,self.length,decryptedData.mutableBytes,decryptedData.length,&dataMoved); if (result == kCCSuccess) { decryptedData.length = dataMoved; return decryptedData; } return nil; }

65、单个页面多个网络请求的情况，需要监听所有网络请求结束后刷新UI

dispatch_group_t group = dispatch_group_create(); dispatch_queue_t serialQueue = dispatch_queue_create("com.wzb.test.www", DISPATCH_QUEUE_SERIAL); dispatch_group_enter(group); dispatch_group_async(group, serialQueue, ^{ // 网络请求一 [WebClick getDataSuccess:^(ResponseModel *model) { dispatch_group_leave(group); } failure:^(NSString *err) { dispatch_group_leave(group); }]; }); dispatch_group_enter(group); dispatch_group_async(group, serialQueue, ^{ // 网络请求二 [WebClick getDataSuccess:getBigTypeRM onSuccess:^(ResponseModel *model) { dispatch_group_leave(group); } failure:^(NSString *errorString) { dispatch_group_leave(group); }]; }); dispatch_group_enter(group); dispatch_group_async(group, serialQueue, ^{ // 网络请求三 [WebClick getDataSuccess:^{ dispatch_group_leave(group); } failure:^(NSString *errorString) { dispatch_group_leave(group); }]; }); // 所有网络请求结束后会来到这个方法 dispatch_group_notify(group, serialQueue, ^{ dispatch_async(dispatch_get_global_queue(0, 0), ^{ dispatch_async(dispatch_get_main_queue(), ^{ // 刷新UI }); }); });

66、解决openUrl延时问题

// 方法一 dispatch_async(dispatch_get_main_queue(), ^{ UIApplication *application = [UIApplication sharedApplication]; if ([application respondsToSelector:@selector(openURL:options:completionHandler:)]) { [application openURL:URL options:@{} completionHandler:nil]; } else { [application openURL:URL]; } }); // 方法二 [self performSelector:@selector(redirectToURL:) withObject:url afterDelay:0.1]; - (void) redirectToURL { UIApplication *application = [UIApplication sharedApplication]; if ([application respondsToSelector:@selector(openURL:options:completionHandler:)]) { [application openURL:URL options:@{} completionHandler:nil]; } else { [application openURL:URL]; } }

67、页面跳转实现翻转动画

// modal方式 TestViewController *vc = [[TestViewController alloc] init]; vc.view.backgroundColor = [UIColor redColor]; vc.modalTransitionStyle = UIModalTransitionStyleCoverVertical; [self presentViewController:vc animated:YES completion:nil]; // push方式 TestViewController *vc = [[TestViewController alloc] init]; vc.view.backgroundColor = [UIColor redColor]; [UIView beginAnimations:@"View Flip" context:nil]; [UIView setAnimationDuration:0.80]; [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut]; [UIView setAnimationTransition:UIViewAnimationTransitionFlipFromRight forView:self.navigationController.view cache:NO]; [self.navigationController pushViewController:vc animated:YES]; [UIView commitAnimations];

68、tableView实现无限滚动

- (void)scrollViewDidScroll:(UIScrollView *)scrollView { CGFloat actualPosition = scrollView.contentOffset.y; CGFloat contentHeight = scrollView.contentSize.height - scrollView.frame.size.height; if (actualPosition >= contentHeight) { [self.dataArr addObjectsFromArray:self.dataArr]; [self.tableView reloadData]; } }

69、代码方式调整屏幕亮度

// brightness属性值在0-1之间，0代表最小亮度，1代表最大亮度 [[UIScreen mainScreen] setBrightness:0.5];

70、获取当前应用CUP用量

float cpu_usage() { kern_return_t kr; task_info_data_t tinfo; mach_msg_type_number_t task_info_count; task_info_count = TASK_INFO_MAX; kr = task_info(mach_task_self(), TASK_BASIC_INFO, (task_info_t)tinfo, &task_info_count); if (kr != KERN_SUCCESS) { return -1; } task_basic_info_t basic_info; thread_array_t thread_list; mach_msg_type_number_t thread_count; thread_info_data_t thinfo; mach_msg_type_number_t thread_info_count; thread_basic_info_t basic_info_th; uint32_t stat_thread = 0; // Mach threads basic_info = (task_basic_info_t)tinfo; // get threads in the task kr = task_threads(mach_task_self(), &thread_list, &thread_count); if (kr != KERN_SUCCESS) { return -1; } if (thread_count > 0) stat_thread += thread_count; long tot_sec = 0; long tot_usec = 0; float tot_cpu = 0; int j; for (j = 0; j < (int)thread_count; j++) { thread_info_count = THREAD_INFO_MAX; kr = thread_info(thread_list[j], THREAD_BASIC_INFO, (thread_info_t)thinfo, &thread_info_count); if (kr != KERN_SUCCESS) { return -1; } basic_info_th = (thread_basic_info_t)thinfo; if (!(basic_info_th->flags & TH_FLAGS_IDLE)) { tot_sec = tot_sec + basic_info_th->user_time.seconds + basic_info_th->system_time.seconds; tot_usec = tot_usec + basic_info_th->user_time.microseconds + basic_info_th->system_time.microseconds; tot_cpu = tot_cpu + basic_info_th->cpu_usage / (float)TH_USAGE_SCALE * 100.0; } } // for each thread kr = vm_deallocate(mach_task_self(), (vm_offset_t)thread_list, thread_count * sizeof(thread_t)); assert(kr == KERN_SUCCESS); return tot_cpu; }

71、float数据取整四舍五入

CGFloat f = 4.65; NSLog(@"%d", (int)f); // 打印结果4 CGFloat f = 4.65; NSLog(@"%d", (int)round(f)); // 打印结果5

72、删除UISearchBar系统默认边框

// 方法一 searchBar.searchBarStyle = UISearchBarStyleMinimal; // 方法二 [searchBar setBackgroundImage:[[UIImage alloc]init]]; // 方法三 searchBar.barTintColor = [UIColor whiteColor];

73、为UICollectionViewCell设置圆角和阴影

cell.contentView.layer.cornerRadius = 2.0f; cell.contentView.layer.borderWidth = 1.0f; cell.contentView.layer.borderColor = [UIColor clearColor].CGColor; cell.contentView.layer.masksToBounds = YES; cell.layer.shadowColor = [UIColor lightGrayColor].CGColor; cell.layer.shadowOffset = CGSizeMake(0, 2.0f); cell.layer.shadowRadius = 2.0f; cell.layer.shadowOpacity = 1.0f; cell.layer.masksToBounds = NO; cell.layer.shadowPath = [UIBezierPath bezierPathWithRoundedRect:cell.bounds cornerRadius:cell.contentView.layer.cornerRadius].CGPath;

74、让正在滑动的scrollView停止滚动(不是禁止，而是暂时停止滚动)

[scrollView setContentOffset:scrollView.contentOffset animated:NO];

75、使用xib设置UIView的边框、圆角

圆角和边框看下图即可设置

xib设置圆角边框.png

但是增加layer.borderColor的keyPath设置边框颜色并不能起作用，后来查了资料，这里应该用layer.borderUIColor，但是这里设置的颜色不起作用，无论设置什么颜色显示出来的都是黑色的。后来又去查了下，有种解决方案是给CALayer添加一个分类，提供一个 - (void)setBorderUIColor:(UIColor *)color;方法就可以解决了，实现如下：

xib设置边框颜色.png #import "CALayer+BorderColor.h" @implementation CALayer (BorderColor) - (void)setBorderUIColor:(UIColor *)color { self.borderColor = color.CGColor; }

76、根据经纬度获取城市等信息

// 创建经纬度 CLLocation *location = [[CLLocation alloc] initWithLatitude:latitude longitude:longitude]; //创建一个译码器 CLGeocoder *cLGeocoder = [[CLGeocoder alloc] init]; [cLGeocoder reverseGeocodeLocation:userLocation completionHandler:^(NSArray *placemarks, NSError *error) { CLPlacemark *place = [placemarks objectAtIndex:0]; // 位置名 　　NSLog(@"name,%@",place.name); 　　// 街道 　　NSLog(@"thoroughfare,%@",place.thoroughfare); 　　// 子街道 　　NSLog(@"subThoroughfare,%@",place.subThoroughfare); 　　// 市 　　NSLog(@"locality,%@",place.locality); 　　// 区 　　NSLog(@"subLocality,%@",place.subLocality); 　　// 国家 　　NSLog(@"country,%@",place.country); } }]; /* CLPlacemark中属性含义 name 地名 thoroughfare 街道 subThoroughfare 街道相关信息，例如门牌等 locality 城市 subLocality 城市相关信息，例如标志性建筑 administrativeArea 直辖市 subAdministrativeArea 其他行政区域信息（自治区等） postalCode 邮编 ISOcountryCode 国家编码 country 国家 inlandWater 水源，湖泊 ocean 海洋 areasOfInterest 关联的或利益相关的地标 */

77、如何防止添加多个NSNotification观察者？

// 解决方案就是添加观察者之前先移除下这个观察者 [[NSNotificationCenter defaultCenter] removeObserver:observer name:name object:object]; [[NSNotificationCenter defaultCenter] addObserver:observer selector:selector name:name object:object];

78、将一个xib添加到另外一个xib上

// 假设你的自定义view名字为CustomView，你需要在CustomView.m中重写 `- (instancetype)initWithCoder:(NSCoder *)aDecoder` 方法，代码如下： - (instancetype)initWithCoder:(NSCoder *)aDecoder { if ((self = [super initWithCoder:aDecoder])) { [self addSubview:[[[NSBundle mainBundle] loadNibNamed:@"CustomView" owner:self options:nil] objectAtIndex:0]]; } return self; } 将一个xib添加到另外一个xib上.png

79、处理字符串，使其首字母大写

NSString *str = @"abcdefghijklmn"; NSString *resultStr; if (str && str.length > 0) { resultStr = [str stringByReplacingCharactersInRange:NSMakeRange(0,1) withString:[[str substringToIndex:1] capitalizedString]]; } NSLog(@"%@", resultStr);

80、判断一个UIAlertView/UIAlertController是否显示

// UIAlertView自带属性 if (alert.visible) { NSLog(@"显示了"); } else { NSLog(@"未显示"); } // UIAlertController没有visible属性，需要自己判断，添加一个全局变量 BOOL visible UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"Title" message:@"message" preferredStyle:UIAlertControllerStyleAlert]; UIAlertAction *alertAction = [UIAlertAction actionWithTitle:@"ActionTitle" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) { self.visible = NO; }]; UIAlertAction *calcelAction = [UIAlertAction actionWithTitle:@"calcelTitle" style:UIAlertActionStyleCancel handler:^(UIAlertAction * _Nonnull action) { self.visible = NO; }]; [alertController addAction:alertAction]; [alertController addAction:calcelAction]; [self presentViewController:alertController animated:YES completion:^{ self.visible = YES; }];

81、获取字符串中的数字

- (NSString *)getNumberFromStr:(NSString *)str { NSCharacterSet *nonDigitCharacterSet = [[NSCharacterSet decimalDigitCharacterSet] invertedSet]; return [[str componentsSeparatedByCharactersInSet:nonDigitCharacterSet] componentsJoinedByString:@""]; } NSLog(@"%@", [self getNumberFromStr:@"a0b0c1d2e3f4fda8fa8fad9fsad23"]); // 00123488923

82、为UIView的某个方向添加边框

// 添加UIView分类 // UIView+WZB.h #import <UIKit/UIKit.h> /** 边框方向 - WZBBorderDirectionTop: 顶部 - WZBBorderDirectionLeft: 左边 - WZBBorderDirectionBottom: 底部 - WZBBorderDirectionRight: 右边 */ typedef NS_ENUM(NSInteger, WZBBorderDirectionType) { WZBBorderDirectionTop = 0, WZBBorderDirectionLeft, WZBBorderDirectionBottom, WZBBorderDirectionRight }; @interface UIView (WZB) /** 为UIView的某个方向添加边框 @param direction 边框方向 @param color 边框颜色 @param width 边框宽度 */ - (void)wzb_addBorder:(WZBBorderDirectionType)direction color:(UIColor *)color width:(CGFloat)width; @end // UIView+WZB.m #import "UIView+WZB.h" @implementation UIView (WZB) - (void)wzb_addBorder:(WZBBorderDirectionType)direction color:(UIColor *)color width:(CGFloat)width { CALayer *border = [CALayer layer]; border.backgroundColor = color.CGColor; switch (direction) { case WZBBorderDirectionTop: { border.frame = CGRectMake(0.0f, 0.0f, self.bounds.size.width, width); } break; case WZBBorderDirectionLeft: { border.frame = CGRectMake(0.0f, 0.0f, width, self.bounds.size.height); } break; case WZBBorderDirectionBottom: { border.frame = CGRectMake(0.0f, self.bounds.size.height - width, self.bounds.size.width, width); } break; case WZBBorderDirectionRight: { border.frame = CGRectMake(self.bounds.size.width - width, 0, width, self.bounds.size.height); } break; default: break; } [self.layer addSublayer:border]; }

83、通过属性设置UISwitch、UIProgressView等控件的宽高

mySwitch.transform = CGAffineTransformMakeScale(5.0f, 5.0f); progressView.transform = CGAffineTransformMakeScale(5.0f, 5.0f);

84、自动搜索功能，用户连续输入的时候不搜索，用户停止输入的时候自动搜索(我这里设置的是0.5s，可根据需求更改)

// 输入框文字改变的时候调用 -(void)searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)searchText{ // 先取消调用搜索方法 [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(searchNewResult) object:nil]; // 0.5秒后调用搜索方法 [self performSelector:@selector(searchNewResult) withObject:nil afterDelay:0.5]; }

85、修改UISearchBar的占位文字颜色

// 方法一（推荐使用） UITextField *searchField = [searchBar valueForKey:@"_searchField"]; [searchField setValue:[UIColor blueColor] forKeyPath:@"_placeholderLabel.textColor"]; // 方法二（已过期） [[UILabel appearanceWhenContainedIn:[UISearchBar class], nil] setTextColor:[UIColor redColor]]; // 方法三（已过期） NSDictionary *placeholderAttributes = @{NSForegroundColorAttributeName : [UIColor redColor], NSFontAttributeName : [UIFont fontWithName:@"HelveticaNeue" size:15],}; NSAttributedString *attributedPlaceholder = [[NSAttributedString alloc] initWithString:searchBar.placeholder attributes:placeholderAttributes]; [[UITextField appearanceWhenContainedIn:[UISearchBar class], nil] setAttributedPlaceholder:attributedPlaceholder];

86、某个界面多个事件同时响应引起的问题(比如，两个button同时按push到新界面，两个都会响应，可能导致push重叠)

// UIView有个属性叫做exclusiveTouch，设置为YES后，其响应事件会和其他view互斥(有其他view事件响应的时候点击它不起作用) view.exclusiveTouch = YES; // 一个一个设置太麻烦了，可以全局设置 [[UIView appearance] setExclusiveTouch:YES]; // 或者只设置button [[UIButton appearance] setExclusiveTouch:YES];

87、修改tabBar的frame

// 子类化UITabBarViewController，我这里以修改tabBar高度为例，重写viewWillLayoutSubviews方法 #import "WZBTabBarViewController.h" @interface WZBTabBarViewController () @end @implementation WZBTabBarViewController - (void)viewWillLayoutSubviews { CGRect tabFrame = self.tabBar.frame; tabFrame.size.height = 100; tabFrame.origin.y = self.view.frame.size.height - 100; self.tabBar.frame = tabFrame; } @end

88、修改键盘背景颜色

// 设置某个键盘颜色 textField.keyboardAppearance = UIKeyboardAppearanceAlert; // 设置工程中所有键盘颜色 [[UITextField appearance] setKeyboardAppearance:UIKeyboardAppearanceAlert];

89、修改image颜色

UIImage *image = [UIImage imageNamed:@"test"]; imageView.image = [image imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate]; CGRect rect = CGRectMake(0, 0, image.size.width, image.size.height); UIGraphicsBeginImageContext(rect.size); CGContextRef context = UIGraphicsGetCurrentContext(); CGContextClipToMask(context, rect, image.CGImage); CGContextSetFillColorWithColor(context, [[UIColor redColor] CGColor]); CGContextFillRect(context, rect); UIImage *img = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); UIImage *flippedImage = [UIImage imageWithCGImage:img.CGImage scale:1.0 orientation: UIImageOrientationDownMirrored]; imageView.image = flippedImage;

90、动画执行removeFromSuperview

[UIView animateWithDuration:0.2 animations:^{ view.alpha = 0.0f; } completion:^(BOOL finished){ [view removeFromSuperview]; }];

91、设置UIButton高亮背景颜色

[UIView animateWithDuration:0.2 animations:^{ view.alpha = 0.0f; } completion:^(BOOL finished){ [view removeFromSuperview]; }];

92、设置UIButton高亮时的背景颜色

// 方法一、子类化UIButton，重写setHighlighted:方法，代码如下 #import "WZBButton.h" @implementation WZBButton - (void)setHighlighted:(BOOL)highlighted { [super setHighlighted:highlighted]; UIColor *normalColor = [UIColor greenColor]; UIColor *highlightedColor = [UIColor redColor]; self.backgroundColor = highlighted ? highlightedColor : normalColor; } // 方法二、利用setBackgroundImage:forState:方法 [button setBackgroundImage:[self imageWithColor:[UIColor blueColor]] forState:UIControlStateHighlighted]; - (UIImage *)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; }

93、关于图片拉伸

推荐看这个博客，讲的很详细http://blog.csdn.net/q199109106q/article/details/8615661

94、利用runtime获取一个类所有属性

- (NSArray *)allPropertyNames:(Class)aClass { unsigned count; objc_property_t *properties = class_copyPropertyList(aClass, &count); NSMutableArray *rv = [NSMutableArray array]; unsigned i; for (i = 0; i < count; i++) { objc_property_t property = properties[i]; NSString *name = [NSString stringWithUTF8String:property_getName(property)]; [rv addObject:name]; } free(properties); return rv; }

95、设置textView的某段文字变成其他颜色

- (void)setupTextView:(UITextView *)textView text:(NSString *)text color:(UIColor *)color { NSMutableAttributedString *string = [[NSMutableAttributedString alloc]initWithString:textView.text]; [string addAttribute:NSForegroundColorAttributeName value:color range:[textView.text rangeOfString:text]]; [textView setAttributedText:string]; }

96、让push跳转动画像modal跳转动画那样效果(从下往上推上来)

- (void)push { TestViewController *vc = [[TestViewController alloc] init]; vc.view.backgroundColor = [UIColor redColor]; CATransition* transition = [CATransition animation]; transition.duration = 0.4f; transition.type = kCATransitionMoveIn; transition.subtype = kCATransitionFromTop; [self.navigationController.view.layer addAnimation:transition forKey:kCATransition]; [self.navigationController pushViewController:vc animated:NO]; } - (void)pop { CATransition* transition = [CATransition animation]; transition.duration = 0.4f; transition.type = kCATransitionReveal; transition.subtype = kCATransitionFromBottom; [self.navigationController.view.layer addAnimation:transition forKey:kCATransition]; [self.navigationController popViewControllerAnimated:NO]; }

97、上传图片太大，压缩图片

-(UIImage *)resizeImage:(UIImage *)image { float actualHeight = image.size.height; float actualWidth = image.size.width; float maxHeight = 300.0; float maxWidth = 400.0; float imgRatio = actualWidth/actualHeight; float maxRatio = maxWidth/maxHeight; float compressionQuality = 0.5;//50 percent compression if (actualHeight > maxHeight || actualWidth > maxWidth) { if(imgRatio < maxRatio) { //adjust width according to maxHeight imgRatio = maxHeight / actualHeight; actualWidth = imgRatio * actualWidth; actualHeight = maxHeight; } else if(imgRatio > maxRatio) { //adjust height according to maxWidth imgRatio = maxWidth / actualWidth; actualHeight = imgRatio * actualHeight; actualWidth = maxWidth; } else { actualHeight = maxHeight; actualWidth = maxWidth; } } CGRect rect = CGRectMake(0.0, 0.0, actualWidth, actualHeight); UIGraphicsBeginImageContext(rect.size); [image drawInRect:rect]; UIImage *img = UIGraphicsGetImageFromCurrentImageContext(); NSData *imageData = UIImageJPEGRepresentation(img, compressionQuality); UIGraphicsEndImageContext(); return [UIImage imageWithData:imageData]; }  

转载于:https://www.cnblogs.com/lujianwenance/p/7154332.html

相关资源：各显卡算力对照表！