多年iOS开发经验总结(二)

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NSInvocationSEL 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      0x100000000double 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yesBOOL 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=Aboutprefs:root=General&path=ACCESSIBILITYprefs:root=AIRPLANE_MODEprefs:root=General&path=AUTOLOCKprefs:root=General&path=USAGE/CELLULAR_USAGEprefs:root=Brightnessprefs:root=Bluetoothprefs:root=General&path=DATE_AND_TIMEprefs:root=FACETIMEprefs:root=Generalprefs:root=General&path=Keyboardprefs:root=CASTLEprefs:root=CASTLE&path=STORAGE_AND_BACKUPprefs:root=General&path=INTERNATIONALprefs:root=LOCATION_SERVICESprefs:root=ACCOUNT_SETTINGSprefs:root=MUSICprefs:root=MUSIC&path=EQprefs:root=MUSIC&path=VolumeLimitprefs:root=General&path=Networkprefs:root=NIKE_PLUS_IPODprefs:root=NOTESprefs:root=NOTIFICATIONS_IDprefs:root=Phoneprefs:root=Photosprefs:root=General&path=ManagedConfigurationListprefs:root=General&path=Resetprefs:root=Sounds&path=Ringtoneprefs:root=Safariprefs:root=General&path=Assistantprefs:root=Soundsprefs:root=General&path=SOFTWARE_UPDATE_LINKprefs:root=STOREprefs:root=TWITTERprefs:root=FACEBOOKprefs:root=General&path=USAGE prefs:root=VIDEOprefs:root=General&path=Network/VPNprefs:root=Wallpaperprefs:root=WIFIprefs:root=INTERNET_TETHERINGprefs:root=Phone&path=Blockedprefs: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]]; }