iOS－－小知识点（持续更新）-白红宇

####一. 颜色渐变

CAGradientLayer *gradientLayer = [CAGradientLayer layer];    gradientLayer.colors = @[(__bridge id)[UIColor whiteColor].CGColor, (__bridge id)[UIColor grayColor].CGColor, (__bridge id)[UIColor whiteColor].CGColor];    gradientLayer.locations = @[@0.0, @0.5, @1.0];    gradientLayer.startPoint = CGPointMake(0, 0);    gradientLayer.endPoint = CGPointMake(1.0, 0);    gradientLayer.frame = CGRectMake(0, 100, 300, 2);    [self.view.layer addSublayer:gradientLayer];复制代码

二. （已删除）

三. 使用drowRect绘制简单图形

//获取上下文    CGContextRef context=UIGraphicsGetCurrentContext();    //设置绘制地区的颜色    CGContextSetRGBFillColor(context, 1, 0, 0, 1);    //设置绘制的位置和大小    CGContextFillRect(context, CGRectMake(0, 100, 100, 100));    NSString * text=@"文字";    UIFont * font=[UIFont systemFontOfSize:14];    //设置文字的位置    [text drawAtPoint:CGPointMake(0, 200) withAttributes:font.fontDescriptor.fontAttributes];    UIImage * img=[UIImage imageNamed:@""];    [img drawInRect:CGRectMake(0, 300, 100, 100)];复制代码

四. 可变数组与不可变数组之间的转换

NSMutableArray * mutablearray=[[NSMutableArray alloc]initWithCapacity:0];    NSArray * copyarray=[mutablearray copy];    copyarray=@[@"1",@"2",@"3"];    NSArray * array=[[NSArray alloc]init];    NSMutableArray * copymutablearray=[array mutableCopy];        [copymutablearray setObject:@"加入到第一位" atIndexedSubscript:0];    [copymutablearray addObject:@"排序加入"];    [copymutablearray addObjectsFromArray:copyarray];复制代码

五. 快速求和，最大值，最小值，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];复制代码

六. 对控件的旋转，平移，缩放，复位

//平移      CGAffineTransform transForm = _pingyibu.transform;     _pingyibu.transform=CGAffineTransformTranslate(transForm, 100, 0);    //旋转    _pingyibu.transform = CGAffineTransformRotate(transForm, M_PI_4);    //缩放按钮    _pingyibu.transform = CGAffineTransformScale(transForm, 1.2, 1.2);    //初始化复位     _pingyibu.transform = CGAffineTransformIdentity;复制代码

七. 设置label的行间距

NSMutableAttributedString *attributedString =    [[NSMutableAttributedString alloc] initWithString:_xuanzhuanla.text];    NSMutableParagraphStyle *paragraphStyle =  [[NSMutableParagraphStyle alloc] init];    [paragraphStyle setLineSpacing:3];    //调整行间距    [attributedString addAttribute:NSParagraphStyleAttributeName                             value:paragraphStyle                             range:NSMakeRange(0, [_xuanzhuanla.text length])];    _xuanzhuanla.attributedText = attributedString;复制代码

八. 让应用直接闪退

AppDelegate *app = [UIApplication sharedApplication].delegate;    UIWindow *window = app.window;    [UIView animateWithDuration:1.0f animations:^{        window.alpha = 0;    } completion:^(BOOL finished) {        exit(0);    }];复制代码

九. 手机震动

AudioServicesPlaySystemSound(kSystemSoundID_Vibrate);复制代码

十. 生成手机唯一ID：UUID

-(NSString*) uuid {    CFUUIDRef puuid = CFUUIDCreate( nil );    CFStringRef uuidString = CFUUIDCreateString( nil, puuid );    NSString * result = (NSString *)CFBridgingRelease(CFStringCreateCopy( NULL, uuidString));    CFRelease(puuid);    CFRelease(uuidString);    return result;}复制代码

十一. label自适应高度

CGRect rect=[la.text boundingRectWithSize:CGSizeMake(WIDTH-70, MAXFLOAT) options:NSStringDrawingUsesLineFragmentOrigin|NSStringDrawingUsesFontLeading attributes:@{NSFontAttributeName:la.font} context:nil];复制代码

十二. 使用AFN判断网络状态

NSURL *url=[NSURL URLWithString:@"http://www.apple.com"];    AFHTTPRequestOperationManager *operationManager=[[AFHTTPRequestOperationManager alloc]initWithBaseURL:url];    //根据不同的网络状态改变去做相应处理    [operationManager.reachabilityManager setReachabilityStatusChangeBlock:^(AFNetworkReachabilityStatus status) {               switch (status) {            case AFNetworkReachabilityStatusReachableViaWWAN:                [self fasongsuoyou];                break;            case AFNetworkReachabilityStatusReachableViaWiFi:                       [self fasongsuoyou];                break;            case AFNetworkReachabilityStatusNotReachable:                [self alert:NSLocalizedString(@"wuwangluo",@"")];                break;            default:                break;        }    }];    //开始监控    [operationManager.reachabilityManager startMonitoring];复制代码

十三. image转换成data类型

NSData *data=UIImagePNGRepresentation(image);NSData *data=UIImageJPEGRepresentation(image, 1.0);复制代码

十四. 获取当前时间和时间戳

//当前时间NSDate *  senddate=[NSDate date];        NSDateFormatter  *dateformatter=[[NSDateFormatter alloc] init];        [dateformatter setDateFormat:@"YYYY-MM-dd HH:mm:ss"];NSString * locationString=[dateformatter stringFromDate:senddate];//当前时间戳NSDate* dat = [NSDate dateWithTimeIntervalSinceNow:0];        NSTimeInterval a=[dat timeIntervalSince1970];        NSString *timeString = [NSString stringWithFormat:@"%f", a];        long s = [timeString intValue];复制代码

十五. 对比时间差

-(int)max:(NSDate *)datatime{    //创建日期格式化对象    NSDateFormatter *dateFormatter=[[NSDateFormatter alloc] init];    [dateFormatter setDateFormat:@"YYYY-MM-dd hh:mm:ss"];    NSDate *  senddate=[NSDate date];    NSString *  locationString=[dateFormatter stringFromDate:senddate];    NSDate *date=[dateFormatter dateFromString:locationString];    //取两个日期对象的时间间隔：    //这里的NSTimeInterval 并不是对象，是基本型，其实是double类型，是由c定义的:typedef double NSTimeInterval;    NSTimeInterval time=[date timeIntervalSinceDate:datatime];    int days=((int)time)/(3600*24);    return days;}复制代码

十六. 使提示框消失（定时）

[alu dismissWithClickedButtonIndex:0 animated:NO];复制代码

十七. 设置self.title的颜色

UIColor * color=[UIColor whiteColor];NSDictionary * dict=[NSDictionary dictionaryWithObject:color forKey:UITextAttributeTextColor];self.navigationController.navigationBar.titleTextAttributes = dict;复制代码

十八. 请求定位权限以及定位属性

//定位管理器    _locationManager=[[CLLocationManager alloc]init];    //如果没有授权则请求用户授权    if ([CLLocationManager authorizationStatus]==kCLAuthorizationStatusNotDetermined){        [_locationManager requestWhenInUseAuthorization];    }else if([CLLocationManager authorizationStatus]==kCLAuthorizationStatusAuthorizedWhenInUse){        //设置代理        _locationManager.delegate=self;        //设置定位精度        _locationManager.desiredAccuracy=kCLLocationAccuracyBest;        //定位频率,每隔多少米定位一次        CLLocationDistance distance=10.0;//十米定位一次        _locationManager.distanceFilter=distance;        //启动跟踪定位        [_locationManager startUpdatingLocation];    }复制代码

十九. 通过经纬度计算距离

BOOL JuLi=NO;    CLLocation *orig=[[CLLocation alloc] initWithLatitude:oldlat  longitude:oldlong];    CLLocation* dist=[[CLLocation alloc] initWithLatitude:nowlat longitude:nowlong];    CLLocationDistance kilometers=[orig distanceFromLocation:dist];    NSLog(@"距离:%f",kilometers);    if (kilometers>=10) {        JuLi=YES;    }    else{        JuLi=NO;    }    return JuLi;复制代码

二十. 弹出效果

/** *  弹出对话框的动画 * *  @param changeOutView 要执行的view *  @param dur           动画时长 */-(void)exChangeOut:(UIView *)changeOutView dur:(CFTimeInterval)dur{    CAKeyframeAnimation * animation;    animation = [CAKeyframeAnimation animationWithKeyPath:@"transform"];    animation.duration = dur;    //animation.delegate = self;    animation.removedOnCompletion = NO;    animation.fillMode = kCAFillModeForwards;    NSMutableArray *values = [NSMutableArray array];    [values addObject:[NSValue valueWithCATransform3D:CATransform3DMakeScale(0.1, 0.1, 1.0)]];    [values addObject:[NSValue valueWithCATransform3D:CATransform3DMakeScale(1.2, 1.2, 1.0)]];    [values addObject:[NSValue valueWithCATransform3D:CATransform3DMakeScale(0.9, 0.9, 0.9)]];    [values addObject:[NSValue valueWithCATransform3D:CATransform3DMakeScale(1.0, 1.0, 1.0)]];    animation.values = values;    animation.timingFunction = [CAMediaTimingFunction functionWithName: @"easeInEaseOut"];    [changeOutView.layer addAnimation:animation forKey:nil];}复制代码

二十一. 设置TextField左右视图

-(id)initWithFrame:(CGRect)frame drawingLeft:(UIImageView *)icon drawingRight:(UIButton *)bu{    self = [super initWithFrame:frame];    if (self) {        self.leftView = icon;        self.leftViewMode = UITextFieldViewModeAlways;        self.rightView= bu;        self.rightViewMode=UITextFieldViewModeAlways;    }    return self;}-(CGRect)leftViewRectForBounds:(CGRect)bounds{    CGRect iconRect = [super leftViewRectForBounds:bounds];    iconRect.origin.x += 5;// 右偏10    return iconRect;}-(CGRect)rightViewRectForBounds:(CGRect)bounds{    CGRect burect=[super rightViewRectForBounds:bounds];    burect.origin.x +=-10;    return burect;}复制代码

二十二. 常用宏定义

#define PUSH(x) AppDelegate *appdelegate=(AppDelegate *)[UIApplication sharedApplication].delegate;[(UINavigationController*)appdelegate.window.rootViewController pushViewController:x animated:YES];#define POP AppDelegate *appdelegate=(AppDelegate *)[UIApplication sharedApplication].delegate;[(UINavigationController*)appdelegate.window.rootViewController popViewControllerAnimated:YES];#define POPROOT OGPAppDelegate *appdelegate=(OGPAppDelegate *)[UIApplication sharedApplication].delegate;[(UINavigationController*)appdelegate.window.rootViewController popToRootViewControllerAnimated:YES];#define IOS7 ([[UIDevice currentDevice].systemVersion floatValue] >= 7.0f)#define IPHONE_4INCH ([UIScreen mainScreen].bounds.size.height > 480.0f)// 随机颜色#define RANDOM_COLOR [UIColor colorWithRed:arc4random_uniform(256) / 255.0 green:arc4random_uniform(256) / 255.0 blue:arc4random_uniform(256) / 255.0 alpha:1]复制代码

二十三. 获取版本号提示版本更新

-(void)VersionButton{    NSString * string=[NSString stringWithContentsOfURL:[NSURL URLWithString:@"http://itunes.apple.com/lookup?id=??????????"] encoding:NSUTF8StringEncoding error:nil];    if (string!=nil && [string length]>0 && [string rangeOfString:@"version"].length==7) {        [self checkenAppUpdate:string];    }}-(void)checkenAppUpdate:(NSString *)appinfo{    NSString * version=[[[NSBundle mainBundle] infoDictionary] objectForKey:@"CFBundleVersion"];    NSString * appInfo1=[appinfo substringFromIndex:[appinfo rangeOfString:@"\"version\":"].location+10];    appInfo1=[[appInfo1 substringToIndex:[appInfo1 rangeOfString:@","].location] stringByReplacingOccurrencesOfString:@"\"" withString:@""];    if (![appInfo1 isEqualToString:version]) {        UIAlertView * alert=[[UIAlertView alloc]initWithTitle:@"" message:[NSString stringWithFormat:@"新版本%@, 已经发布",appInfo1] delegate:self cancelButtonTitle:@"知道了" otherButtonTitles: nil];        alert.delegate=self;        [alert addButtonWithTitle:@"前往更新"];        [alert show];        alert.tag=20;    }}-(void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex{    if (buttonIndex==1 & alertView.tag==20) {        NSString * url=@"https://appsto.re/cn/-naScb.i";        [[UIApplication sharedApplication] openURL:[NSURL URLWithString:url]];    }}复制代码

二十四. 获取设备或APP信息

//返回应用程序名称+(NSString *) getAppName{    NSDictionary *infoDictionary = [[NSBundle mainBundle] infoDictionary];    return [infoDictionary objectForKey:@"CFBundleDisplayName"];}//返回应用版本号+(NSString *) getAppVersion{    NSDictionary *infoDictionary = [[NSBundle mainBundle] infoDictionary];    return [infoDictionary objectForKey:@"CFBundleShortVersionString"];}+(NSString *) getAppBundleVersion{    NSDictionary *infoDictionary = [[NSBundle mainBundle] infoDictionary];    return [infoDictionary objectForKey:@"CFBundleVersion"];}//设备型号+(NSString *) getSystemName{    return [[UIDevice currentDevice] systemName];}//设备版本号+(NSString *) getSystemVersion{    return [[UIDevice currentDevice] systemVersion];}复制代码

二十五. 内存泄漏分析

静态分析内存泄露 使用Xcode自带的Analyze功能（Product-> Analyze）（Shift + Command + B），对代码进行静态分析，对于内存泄露（Potential Memory Leak）, 未使用局部变量(dead store)，逻辑错误(Logic Flaws)以及API使用问题(API-usage)等明确的展示出来。 静态分析的内存泄露情况比较简单，开发者都能很快的解决。这里不做赘述。动态分析内存泄露 使用Xcode自带的Profile功能（Product-> Profile）（Command + i）弹出工具框，选择Leaks打开，选择运行设备点左上角的Record录制按钮，项目就会在已选好的设备上运行，并开始录制内存检测情况。选Leaks查看泄露情况，在Leaks的详细菜单Details选项里选调用树Call Tree，可查看所有内存泄露发生在哪些地方。再在右侧的齿轮设置-Call Tree-勾选Hide System Libraries，则可直接看内存泄露发生的函数名、方法名。点击函数名、方法名，可直接跳到函数方法的细节，可以看到哪一句代码出现了内存泄露，以及泄露了多少内存。复制代码

接下来就要回到Xcode，找到出现内存泄露的函数方法，仔细分析如何出现的内存泄露; 一般使用ARC，按照上面一提到的内存理解和编码习惯是不会出现内存泄露的。但我们在开发过程中，经常要使用第三方的一些类库，特别是涉及到加密的类库，用c或c++来编码的加密解密方法，会出现内存泄露。此时，我们要明白这些内存分配，需要手动释放。要一步一步看，哪里分配了内存，在使用完之后一定要记得释放free它。

二十六. block循环利用导致内存泄漏

A *a = [[A alloc] init]; a.finishBlock = ^(NSDictionary paraments){ [a doSomething]; }; 对于这种在block块里引用对象a的情况，要在创建对象a时加修饰符block来防止循环引用。 block A *a = [[A alloc] init]; a.finishBlock = ^(NSDictionary paraments){ [a doSomething]; }; 或 A __block a = [[A alloc] init]; a.finishBlock = ^(NSDictionary paraments){ [a doSomething]; }; 或者，需要在block中调用用self的方法、属性、变量时，可以这样写__weak typeof(self) weakSelf = self;在block中使用weakSelf。 __weak typeof(self) weakSelf = self; [b doSomethingWithFinishBlock:^{ weakSelf.text = @"内存检测"; [weakSelf doSomething]; }];复制代码

二十七. label 的空格属性和局部字段颜色

设置 label 的 autoresizingMask 为 NO ,可以使用空格间隔字符串!    NSMutableAttributedString *hintString=[[NSMutableAttributedString alloc]initWithString:@"点击注册按钮服务协议"];      //获取要调整颜色的文字位置,调整颜色      NSRange range1=[[hintString string]rangeOfString:@"注册"];      [hintString addAttribute:NSForegroundColorAttributeName value:[UIColor greenColor] range:range1];      NSRange range2=[[hintString string]rangeOfString:@"服务协议"];      [hintString addAttribute:NSForegroundColorAttributeName value:[UIColor redColor] range:range2];      hintLabel.attributedText=hintString;复制代码

二十八. 过滤特殊字符

// 定义一个特殊字符的集合    NSCharacterSet *set = [NSCharacterSet characterSetWithCharactersInString:    @"@／：；（）¥「」＂、[]{}#%-*+=_\\|~＜＞$€^•'@#$%^&*()_+'\""];    // 过滤字符串的特殊字符    NSString *newString = [trimString stringByTrimmingCharactersInSet:set];复制代码

二十九. 设置滑动的时候隐藏 navigationbar

第1种:        navigationController.hidesBarsOnSwipe = Yes    第2种:        //1.当我们的手离开屏幕时候隐藏    - (void)scrollViewWillEndDragging:(UIScrollView *)scrollView withVelocity:(CGPoint)velocity targetContentOffset:(inout CGPoint *)targetContentOffset    {         if(velocity.y > 0)         {        [self.navigationController setNavigationBarHidden:YES animated:YES];        } else {        [self.navigationController setNavigationBarHidden:NO animated:YES];         }    }    velocity.y这个量，在上滑和下滑时，变化极小（小数），但是因为方向不同，有正负之分，这就很好处理  了。复制代码

三十. 屏幕截图

// 1. 开启一个与图片相关的图形上下文    UIGraphicsBeginImageContextWithOptions(self.view.bounds.size,NO,0.0);    // 2. 获取当前图形上下文    CGContextRef ctx = UIGraphicsGetCurrentContext();    // 3. 获取需要截取的view的layer    [self.view.layer renderInContext:ctx];    // 4. 从当前上下文中获取图片    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();    // 5. 关闭图形上下文    UIGraphicsEndImageContext();    // 6. 把图片保存到相册    UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil);复制代码

三十一. 去掉 tabbar 和 navgationbar 的黑线

//去掉tabBar顶部线条    CGRect rect = CGRectMake(0, 0, 1, 1);    UIGraphicsBeginImageContext(rect.size);    CGContextRef context = UIGraphicsGetCurrentContext();    CGContextSetFillColorWithColor(context, [[UIColor clearColor] CGColor]);    CGContextFillRect(context, rect);    UIImage *img = UIGraphicsGetImageFromCurrentImageContext();    UIGraphicsEndImageContext();    [self.tabBar setBackgroundImage:img];    [self.tabBar setShadowImage:img];    //[self.navigationController.navigationBar setBackgroundImage:img];    //self.navigationController.navigationBar.shadowImage = ima;    self.tabBar.backgroundColor = SLIVERYCOLOR;复制代码

三十二. 判断字符串中是否含有中文

-(BOOL)isChinese:(NSString *)str{        NSString *match=@"(^[\u4e00-\u9fa5]+$)";        NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF matches %@", match];        return [predicate evaluateWithObject:str];    }复制代码

三十三. 解决父视图和子视图的手势冲突问题

/** 解决手势冲突 */    - (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch{        if ([touch.view isDescendantOfView:cicView]) {            return NO;        }        return YES;    }复制代码

三十四. 获取当前连接的Wi-Fi的名称

NSString *wifiName = @"Not Found";        CFArrayRef myArray = CNCopySupportedInterfaces();        if (myArray != nil) {            CFDictionaryRef myDict = CNCopyCurrentNetworkInfo(CFArrayGetValueAtIndex(myArray, 0));            if (myDict != nil) {                NSDictionary *dict = (NSDictionary*)CFBridgingRelease(myDict);                wifiName = [dict valueForKey:@"SSID"];            }        }复制代码

三十五. 跨控制器跳转返回

for (UIViewController *controller in self.navigationController.viewControllers) {         if ([controller isKindOfClass:[@“你要返回的控制器类名” class]]) {             [self.navigationController popToViewController:controller animated:YES];         }     }复制代码

三十六. layer.cornerRadius 圆角流畅性的优化

loginBtn.layer.rasterizationScale = [UIScreen mainScreen].scale;复制代码

三十七. 导航栏和下方视图间隔距离消失

self.automaticallyAdjustsScrollViewInsets=YES;复制代码

三十八. 毛玻璃效果(ios8.0以后的版本)

UIVisualEffectView *visualEffectView = [[UIVisualEffectView alloc] initWithEffect:[UIBlurEffect effectWithStyle:UIBlurEffectStyleLight]];    visualEffectView.frame = CGRectMake(0, 0, 320*[FlexibleFrame ratio], 180*[FlexibleFrame ratio]);    visualEffectView.alpha = 1.0;复制代码

三十九. 移动工程不需要配置路径

创建.pch文件时 , BuildSetting 中的 Prefix Header 中的路径开头可以写 $(SRCROOT)/工程地址, 这样写的好处可以使你的挪动代码不用手动更换路径!

四十. 判断两个数组是否相同

NSArray *array1 = [NSArray arrayWithObjects:@"a", @"b", @"c",  nil];    NSArray *array2 = [NSArray arrayWithObjects:@"d", @"a", @"c",  nil];    bool bol = false;    //创建俩新的数组    NSMutableArray *oldArr = [NSMutableArray arrayWithArray:array1];    NSMutableArray *newArr = [NSMutableArray arrayWithArray:array2];    //对数组1排序。    [oldArr sortUsingComparator:^NSComparisonResult(id obj1, id obj2){        return obj1 > obj2;    }];    //对数组2排序。    [newArr sortUsingComparator:^NSComparisonResult(id obj1, id obj2){        return obj1 > obj2;    }];    if (newArr.count == oldArr.count) {        bol = true;        for (int16_t i = 0; i < oldArr.count; i++) {            id c1 = [oldArr objectAtIndex:i];            id newc = [newArr objectAtIndex:i];            if (![newc isEqualToString:c1]) {                bol = false;                break;            }        }    }    if (bol) {        NSLog(@" ------------- 两个数组的内容相同！");    }    else {        NSLog(@"-=-------------两个数组的内容不相同！");    }复制代码

四十一. block

对于block，都应该使用copy来声明，原因是block来捕获上下文的信息

四十二. 使应用在后台运行

- (void)applicationDidEnterBackground:(UIApplication *)application  {      __block UIBackgroundTaskIdentifier bgTask = UIBackgroundTaskInvalid;      bgTask = [application beginBackgroundTaskWithExpirationHandler:^{          dispatch_async(dispatch_get_main_queue(), ^{              if (bgTask != UIBackgroundTaskInvalid) {                  bgTask = UIBackgroundTaskInvalid;              }          });      }];      dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{          dispatch_async(dispatch_get_main_queue(), ^{              if (bgTask != UIBackgroundTaskInvalid) {                  bgTask = UIBackgroundTaskInvalid;              }          });      });  }  复制代码

但其实不是应用一直在运行。

四十三. 计算一段NSString在视图中渲染出来的尺寸

+ (CGSize)sizeOfString:(NSString *)textString font:(UIFont *)font bound:(CGSize)bound {      NSMutableParagraphStyle * paragraphStyle = [[NSMutableParagraphStyle alloc] init];      paragraphStyle.lineBreakMode = NSLineBreakByWordWrapping;      paragraphStyle.alignment = NSTextAlignmentLeft;      if (font == nil) {          font = [UIFont systemFontOfSize:[UIFont systemFontSize]];      }      NSDictionary * attributes = @{NSFontAttributeName : font,                                    NSParagraphStyleAttributeName : paragraphStyle};            NSAttributedString* attributedString = [[NSAttributedString alloc] initWithString:textString attributes:attributes];      return [TTTAttributedLabel sizeThatFitsAttributedString:attributedString                                              withConstraints:CGSizeMake(bound.width, 999)                                       limitedToNumberOfLines:0];  }  复制代码

四十四. 获取相应的字体类型名

for(NSString *fontfamilyname in [UIFont familyNames])  {      NSLog(@"Family:'%@'",fontfamilyname);      for(NSString *fontName in [UIFont fontNamesForFamilyName:fontfamilyname])      {          NSLog(@"\tfont:'%@'",fontName);      }      NSLog(@"~~~~~~~~");  }  复制代码

四十五. Masonry和SVProgreaaHUD需要注意

使用Masonry约束TTTAttributedLabel的时候，初始化TTTAttributedLabel需要设置frame为CGRectZero，否则约束会不生效。SVProgressHUD如果要自定义一些属性，比如loading状态转圈的颜色，必须先设置style为SVProgressHUDStyleCustom，这样自定义的状态才会生效。复制代码

四十六. 打印View所有子视图

po [[self view]recursiveDescription]复制代码

四十七. layoutSubviews调用的调用时机

* 当视图第一次显示的时候会被调用* 当这个视图显示到屏幕上了,点击按钮* 添加子视图也会调用这个方法* 当本视图的大小发生改变的时候是会调用的* 当子视图的frame发生改变的时候是会调用的* 当删除子视图的时候是会调用的复制代码

四十八. UIImageView填充模式

@"UIViewContentModeScaleToFill",      // 拉伸自适应填满整个视图  @"UIViewContentModeScaleAspectFit",   // 自适应比例大小显示  @"UIViewContentModeScaleAspectFill",  // 原始大小显示  @"UIViewContentModeRedraw",           // 尺寸改变时重绘  @"UIViewContentModeCenter",           // 中间  @"UIViewContentModeTop",              // 顶部  @"UIViewContentModeBottom",           // 底部  @"UIViewContentModeLeft",             // 中间贴左  @"UIViewContentModeRight",            // 中间贴右  @"UIViewContentModeTopLeft",          // 贴左上  @"UIViewContentModeTopRight",         // 贴右上  @"UIViewContentModeBottomLeft",       // 贴左下  @"UIViewContentModeBottomRight",      // 贴右下复制代码

四十九. MRC和ARC混编设置方式

在XCode中targets的build phases选项下Compile Sources下选择不需要arc编译的文件双击输入 -fno-objc-arc 即可 MRC工程中也可以使用ARC的类，方法如下：在XCode中targets的build phases选项下Compile Sources下选择要使用arc编译的文件双击输入 -fobjc-arc 即可

五十. 解决tableview的分割线短一截

-(void)viewDidLayoutSubviews{if ([self.tableView respondsToSelector:@selector(setSeparatorInset:)]){ [self.tableView setSeparatorInset:UIEdgeInsetsMake(0,0,0,0)];}if ([self.tableView respondsToSelector:@selector(setLayoutMargins:)]) {[self.tableView setLayoutMargins:UIEdgeInsetsMake(0,0,0,0)]; }}-(void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath{if ([cell respondsToSelector:@selector(setSeparatorInset:)]) {[cell setSeparatorInset:UIEdgeInsetsZero]; } if ([cell respondsToSelector:@selector(setLayoutMargins:)]) {[cell setLayoutMargins:UIEdgeInsetsZero]; }}复制代码

五十一. 修改textFieldplaceholder字体颜色和大小

textField.placeholder = @"username is in here!";  [textField setValue:[UIColor redColor] forKeyPath:@"_placeholderLabel.textColor"];  [textField setValue:[UIFont boldSystemFontOfSize:16] forKeyPath:@"_placeholderLabel.font"];复制代码

五十二. 修改状态栏字体颜色

只能设置两种颜色，黑色和白色，系统默认黑色设置为白色方法：（1）在plist里面添加Status bar style，值为UIStatusBarStyleLightContent（白色）或UIStatusBarStyleDefault（黑 色）（2）在Info.plist中设置UIViewControllerBasedStatusBarAppearance 为NO复制代码

五十三.调用相机后状态栏消失

[[UIApplication sharedApplication] setStatusBarHidden:NO animated:NO];[[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleBlackTranslucent animated:YES];复制代码

五十四. 修改UIAlertController字体颜色

//修改title  NSMutableAttributedString *alertControllerStr = [[NSMutableAttributedString alloc] initWithString:@"提示"];  [alertControllerStr addAttribute:NSForegroundColorAttributeName value:[UIColor redColor] range:NSMakeRange(0, 2)];  [alertControllerStr addAttribute:NSFontAttributeName value:[UIFont systemFontOfSize:17] range:NSMakeRange(0, 2)];  if (alertController valueForKey:@"attributedTitle") {      [alertController setValue:alertControllerStr forKey:@"attributedTitle"];  }  //修改message  NSMutableAttributedString *alertControllerMessageStr = [[NSMutableAttributedString alloc] initWithString:@"提示内容"];  [alertControllerMessageStr addAttribute:NSForegroundColorAttributeName value:[UIColor greenColor] range:NSMakeRange(0, 4)];  [alertControllerMessageStr addAttribute:NSFontAttributeName value:[UIFont systemFontOfSize:20] range:NSMakeRange(0, 4)];  if (alertController valueForKey:@"attributedMessage") {      [alertController setValue:alertControllerMessageStr forKey:@"attributedMessage"];  }//修改按钮字体颜色UIAlertAction *defaultAction = [UIAlertAction actionWithTitle:@"Default" style:UIAlertActionStyleDefault handler:nil];[alertController addAction:defaultAction]; if (cancelAction valueForKey:@"titleTextColor") {      [cancelAction setValue:[UIColor redColor] forKey:@"titleTextColor"];  }复制代码

五十五. 使用钥匙串保存设备唯一ID

下载并倒入SSKeyChain的.h和.m文件，并添加Security.framework框架

+ (NSString *)getDeviceId{    NSString * currentDeviceUUIDStr = [SSKeychain passwordForService:@" "account:@"uuid"];    if (currentDeviceUUIDStr == nil || [currentDeviceUUIDStr isEqualToString:@""])    {        NSUUID * currentDeviceUUID  = [UIDevice currentDevice].identifierForVendor;        currentDeviceUUIDStr = currentDeviceUUID.UUIDString;        currentDeviceUUIDStr = [currentDeviceUUIDStr stringByReplacingOccurrencesOfString:@"-" withString:@""];        currentDeviceUUIDStr = [currentDeviceUUIDStr lowercaseString];        [SSKeychain setPassword: currentDeviceUUIDStr forService:@" "account:@"uuid"];    }    return currentDeviceUUIDStr;}复制代码

五十六. 获取设备型号

引入头文件

#include <sys/types.h> #include <sys/sysctl.h>

+ (NSString *)getCurrentDeviceModel{    int mib[2];    size_t len;    char *machine;        mib[0] = CTL_HW;    mib[1] = HW_MACHINE;    sysctl(mib, 2, NULL, &len, NULL, 0);    machine = malloc(len);    sysctl(mib, 2, machine, &len, NULL, 0);        NSString *platform = [NSString stringWithCString:machine encoding:NSASCIIStringEncoding];    free(machine);    // iPhone    if ([platform isEqualToString:@"iPhone1,1"]) return @"iPhone2G";    if ([platform isEqualToString:@"iPhone1,2"]) return @"iPhone3G";    if ([platform isEqualToString:@"iPhone2,1"]) return @"iPhone3GS";    if ([platform isEqualToString:@"iPhone3,1"]) return @"iPhone4";    if ([platform isEqualToString:@"iPhone3,2"]) return @"iPhone4";    if ([platform isEqualToString:@"iPhone3,3"]) return @"iPhone4";    if ([platform isEqualToString:@"iPhone4,1"]) return @"iPhone4S";    if ([platform isEqualToString:@"iPhone5,1"]) return @"iPhone5";    if ([platform isEqualToString:@"iPhone5,2"]) return @"iPhone5";    if ([platform isEqualToString:@"iPhone5,3"]) return @"iPhone5c";    if ([platform isEqualToString:@"iPhone5,4"]) return @"iPhone5c";    if ([platform isEqualToString:@"iPhone6,1"]) return @"iPhone5s";    if ([platform isEqualToString:@"iPhone6,2"]) return @"iPhone5s";    if ([platform isEqualToString:@"iPhone7,2"]) return @"iPhone6";    if ([platform isEqualToString:@"iPhone7,1"]) return @"iPhone6Plus";    if ([platform isEqualToString:@"iPhone8,1"]) return @"iPhone6s";    if ([platform isEqualToString:@"iPhone8,2"]) return @"iPhone6sPlus";    if ([platform isEqualToString:@"iPhone8,3"]) return @"iPhoneSE";    if ([platform isEqualToString:@"iPhone8,4"]) return @"iPhoneSE";    if ([platform isEqualToString:@"iPhone9,1"]) return @"iPhone7";    if ([platform isEqualToString:@"iPhone9,2"]) return @"iPhone7Plus";        //iPod Touch    if ([platform isEqualToString:@"iPod1,1"])   return @"iPodTouch";    if ([platform isEqualToString:@"iPod2,1"])   return @"iPodTouch2G";    if ([platform isEqualToString:@"iPod3,1"])   return @"iPodTouch3G";    if ([platform isEqualToString:@"iPod4,1"])   return @"iPodTouch4G";    if ([platform isEqualToString:@"iPod5,1"])   return @"iPodTouch5G";    if ([platform isEqualToString:@"iPod7,1"])   return @"iPodTouch6G";        //iPad    if ([platform isEqualToString:@"iPad1,1"])   return @"iPad";    if ([platform isEqualToString:@"iPad2,1"])   return @"iPad2";    if ([platform isEqualToString:@"iPad2,2"])   return @"iPad2";    if ([platform isEqualToString:@"iPad2,3"])   return @"iPad2";    if ([platform isEqualToString:@"iPad2,4"])   return @"iPad2";    if ([platform isEqualToString:@"iPad3,1"])   return @"iPad3";    if ([platform isEqualToString:@"iPad3,2"])   return @"iPad3";    if ([platform isEqualToString:@"iPad3,3"])   return @"iPad3";    if ([platform isEqualToString:@"iPad3,4"])   return @"iPad4";    if ([platform isEqualToString:@"iPad3,5"])   return @"iPad4";    if ([platform isEqualToString:@"iPad3,6"])   return @"iPad4";        //iPad Air    if ([platform isEqualToString:@"iPad4,1"])   return @"iPadAir";    if ([platform isEqualToString:@"iPad4,2"])   return @"iPadAir";    if ([platform isEqualToString:@"iPad4,3"])   return @"iPadAir";    if ([platform isEqualToString:@"iPad5,3"])   return @"iPadAir2";    if ([platform isEqualToString:@"iPad5,4"])   return @"iPadAir2";        //iPad mini    if ([platform isEqualToString:@"iPad2,5"])   return @"iPadmini1G";    if ([platform isEqualToString:@"iPad2,6"])   return @"iPadmini1G";    if ([platform isEqualToString:@"iPad2,7"])   return @"iPadmini1G";    if ([platform isEqualToString:@"iPad4,4"])   return @"iPadmini2";    if ([platform isEqualToString:@"iPad4,5"])   return @"iPadmini2";    if ([platform isEqualToString:@"iPad4,6"])   return @"iPadmini2";    if ([platform isEqualToString:@"iPad4,7"])   return @"iPadmini3";    if ([platform isEqualToString:@"iPad4,8"])   return @"iPadmini3";    if ([platform isEqualToString:@"iPad4,9"])   return @"iPadmini3";    if ([platform isEqualToString:@"iPad5,1"])   return @"iPadmini4";    if ([platform isEqualToString:@"iPad5,2"])   return @"iPadmini4";        if ([platform isEqualToString:@"i386"])      return @"iPhoneSimulator";    if ([platform isEqualToString:@"x86_64"])    return @"iPhoneSimulator";    return platform;}复制代码

五十七. 减少发布之后过多的NSLog带来的性能影响

#if defined(DEBUG)||defined(_DEBUG)    NSLog(@"测试代码");    NSLog(@"Test Coding");#endif复制代码

五十八. 去掉字符串的前后空格（基本用在textfield）

NSString *textName = [self.nameCell.textField.text stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];复制代码

五十九. 截取字符串到指定字符的位置

NSString *string = @"abcdefghijklmn";NSRange range = [string rangeOfString:@"h"];string = [string substringToIndex:range.location];复制代码

六十. 获取label的行数和每行的内容

- (NSArray *)getLinesArrayOfStringInLabel:(UILabel *)label{    NSString *text = [label text];    UIFont *font = [label font];    CGRect rect = [label frame];    CTFontRef myFont = CTFontCreateWithName(( CFStringRef)([font fontName]), [font pointSize], NULL);    NSMutableAttributedString *attStr = [[NSMutableAttributedString alloc] initWithString:text];    [attStr addAttribute:(NSString *)kCTFontAttributeName value:(__bridge  id)myFont range:NSMakeRange(0, attStr.length)];    CFRelease(myFont);    CTFramesetterRef frameSetter = CTFramesetterCreateWithAttributedString(( CFAttributedStringRef)attStr);    CGMutablePathRef path = CGPathCreateMutable();    CGPathAddRect(path, NULL, CGRectMake(0,0,rect.size.width,100000));    CTFrameRef frame = CTFramesetterCreateFrame(frameSetter, CFRangeMake(0, 0), path, NULL);    NSArray *lines = ( NSArray *)CTFrameGetLines(frame);    NSMutableArray *linesArray = [[NSMutableArray alloc]init];    for (id line in lines) {        CTLineRef lineRef = (__bridge  CTLineRef )line;        CFRange lineRange = CTLineGetStringRange(lineRef);        NSRange range = NSMakeRange(lineRange.location, lineRange.length);        NSString *lineString = [text substringWithRange:range];        CFAttributedStringSetAttribute((CFMutableAttributedStringRef)attStr, lineRange, kCTKernAttributeName, (CFTypeRef)([NSNumber numberWithFloat:0.0]));        CFAttributedStringSetAttribute((CFMutableAttributedStringRef)attStr, lineRange, kCTKernAttributeName, (CFTypeRef)([NSNumber numberWithInt:0.0]));        //NSLog(@"''''''''''''''''''%@",lineString);        [linesArray addObject:lineString];    }    CGPathRelease(path);    CFRelease( frame );    CFRelease(frameSetter);    return (NSArray *)linesArray;}复制代码

六十一.键盘透明

[UITextField alloc].keyboardAppearance = UIKeyboardAppearanceAlert; 复制代码

六十二.状态栏的网络活动风火轮是否旋转,默认为NO

[UIApplication sharedApplication].networkActivityIndicatorVisible = NO; 复制代码

六十三.开启右滑返回

self.navigationController.interactivePopGestureRecognizer.delegate = nil; 复制代码

六十四.MD5加密

#import "NSString+MD5.h"#import 
    
     复制代码

- (NSString *)stringToMD5:(NSString *)str{//1.首先将字符串转换成UTF-8编码, 因为MD5加密是基于C语言的,所以要先把字符串转化成C语言的字符串    const char *fooData = [str UTF8String];//2.然后创建一个字符串数组,接收MD5的值    unsigned char result[CC_MD5_DIGEST_LENGTH];//3.计算MD5的值, 这是官方封装好的加密方法:把我们输入的字符串转换成16进制的32位数,然后存储到result中    CC_MD5(fooData, (CC_LONG)strlen(fooData), result);    /**    第一个参数:要加密的字符串    第二个参数: 获取要加密字符串的长度    第三个参数: 接收结果的数组    *///4.创建一个字符串保存加密结果    NSMutableString *saveResult = [NSMutableString string];//5.从result 数组中获取加密结果并放到 saveResult中    for (int i = 0; i < CC_MD5_DIGEST_LENGTH; i++) {        [saveResult appendFormat:@"%02x", result];    }    /*       x表示十六进制，%02X  意思是不足两位将用0补齐，如果多余两位则不影响        NSLog("%02X", 0x888);  //888        NSLog("%02X", 0x4); //04     */    return saveResult;} 复制代码

六十五.导航栏返回按钮颜色设置及文字变成<

-(void)UIBarButtonBackItemSet{    [[UIBarButtonItem appearance] setBackButtonTitlePositionAdjustment:UIOffsetMake(0, -60)                                                         forBarMetrics:UIBarMetricsDefault];        self.navigationController.navigationBar.barStyle = UIStatusBarStyleDefault;    [self.navigationController.navigationBar setTintColor:[UIColor whiteColor]];}复制代码

六十六.字符串中包含双引号和反斜杠处理

NSString * testStr = @"你好，\"你好\"";  NSLog(@"%@",testStr);  //输出结果为：你好，"你好" NSString * testStr = @"不好，\\不好\\\\"; NSLog(@"%@",testStr);//输出结果为：不好，\不好\\复制代码

##待续！！复制代码