iOS常见使用技巧汇总

来源:互联网 发布:js根据当前时间年月日 编辑:程序博客网 时间:2024/06/06 02:35
  1. 打印View所有子视图
    po [[self view]recursiveDescription]
  2. 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

  3. NSString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];
  4. TransForm属性
    //平移按钮CGAffineTransform transForm = self.buttonView.transform;self.buttonView.transform = CGAffineTransformTranslate(transForm, 10, 0);//旋转按钮CGAffineTransform transForm = self.buttonView.transform;self.buttonView.transform = CGAffineTransformRotate(transForm, M_PI_4);//缩放按钮self.buttonView.transform = CGAffineTransformScale(transForm, 1.2, 1.2);//初始化复位self.buttonView.transform = CGAffineTransformIdentity;
  5. 去掉分割线多余15像素
    //首先在viewDidLoad方法加入以下代码:if ([self.tableView respondsToSelector:@selector(setSeparatorInset:)]) {     [self.tableView setSeparatorInset:UIEdgeInsetsZero];    }   if ([self.tableView respondsToSelector:@selector(setLayoutMargins:)]) {             [self.tableView setLayoutMargins:UIEdgeInsetsZero];}//然后在重写willDisplayCell方法- (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];     }}
  6. 计算方法耗时时间间隔
    // 获取时间间隔#define TICK   CFAbsoluteTime start = CFAbsoluteTimeGetCurrent();#define TOCK   NSLog(@"Time: %f", CFAbsoluteTimeGetCurrent() - start)
  7. Color颜色宏定义
    // 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]// 颜色(RGB)#define RGBCOLOR(r, g, b) [UIColor colorWithRed:(r)/255.0f green:(g)/255.0f blue:(b)/255.0f alpha:1]// 利用这种方法设置颜色和透明值,可不影响子视图背景色#define RGBACOLOR(r, g, b, a) [UIColor colorWithRed:(r)/255.0f green:(g)/255.0f blue:(b)/255.0f alpha:(a)]
  8. Alert提示宏定义
    #define Alert(_S_, ...) [[[UIAlertView alloc] initWithTitle:@"提示" message:[NSString stringWithFormat:(_S_), ##__VA_ARGS__] delegate:nil cancelButtonTitle:@"确定" otherButtonTitles:nil] show]
  9. 让iOS应用直接退出

    - (void)exitApplication { AppDelegate *app = [UIApplication sharedApplication].delegate; UIWindow *window = app.window; [UIView animateWithDuration:1.0f animations:^{     window.alpha = 0; } completion:^(BOOL finished) {     exit(0); }];}
  10. NSArray 快速求总和 最大值 最小值 和 平均值
    NSArray *array = [NSArray arrayWithObjects:@"2.0", @"2.3", @"3.0", @"4.0", @"10", nil];CGFloat sum = [[array valueForKeyPath:@"@sum.floatValue"] floatValue];CGFloat avg = [[array valueForKeyPath:@"@avg.floatValue"] floatValue];CGFloat max =[[array valueForKeyPath:@"@max.floatValue"] floatValue];CGFloat min =[[array valueForKeyPath:@"@min.floatValue"] floatValue];NSLog(@"%f\n%f\n%f\n%f",sum,avg,max,min);
  11. 修改Label中不同文字颜色
    - (void)touchesEnded:(NSSet<UITouch> *)touches withEvent:(UIEvent *)event{[self editStringColor:self.label.text editStr:@"好" color:[UIColor blueColor]];}- (void)editStringColor:(NSString *)string editStr:(NSString *)editStr color:(UIColor *)color {// string为整体字符串, editStr为需要修改的字符串NSRange range = [string rangeOfString:editStr];NSMutableAttributedString *attribute = [[NSMutableAttributedString alloc] initWithString:string];// 设置属性修改字体颜色UIColor与大小UIFont[attribute addAttributes:@{NSForegroundColorAttributeName:color} range:range];self.label.attributedText = attribute;}
  12. 播放声音
    #import<AVFoundation>//  1.获取音效资源的路径NSString *path = [[NSBundle mainBundle]pathForResource:@"pour_milk" ofType:@"wav"];//  2.将路劲转化为urlNSURL *tempUrl = [NSURL fileURLWithPath:path];//  3.用转化成的url创建一个播放器NSError *error = nil;AVAudioPlayer *play = [[AVAudioPlayer alloc]initWithContentsOfURL:tempUrl error:&error];self.player = play;//  4.播放[play play];
  13. 检测是否IPad Pro
    - (BOOL)isIpadPro{   UIScreen *Screen = [UIScreen mainScreen];   CGFloat width = Screen.nativeBounds.size.width/Screen.nativeScale;  CGFloat height = Screen.nativeBounds.size.height/Screen.nativeScale;         BOOL isIpad =[[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPad;   BOOL hasIPadProWidth = fabs(width - 1024.f) < DBL xss=removed xss=removed xss=removed xss=removed xss=removed xss=removed xss=removed xss=removed xss=removed>> ~/.lldbinitecho target stop-hook add -o \"target stop-hook disable\" >> ~/.lldbinit//下次重新运行项目,然后就不报错了。
  14. Label行间距

    -(void)test{NSMutableAttributedString *attributedString =    [[NSMutableAttributedString alloc] initWithString:self.contentLabel.text];NSMutableParagraphStyle *paragraphStyle =  [[NSMutableParagraphStyle alloc] init];  [paragraphStyle setLineSpacing:3];//调整行间距       [attributedString addAttribute:NSParagraphStyleAttributeName                      value:paragraphStyle                      range:NSMakeRange(0, [self.contentLabel.text length])]; self.contentLabel.attributedText = attributedString;}
  15. 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
  16. 宏定义检测block是否可用
    #define BLOCK_EXEC&#40;block, ...&#41; if (block) { block(__VA_ARGS__); };   // 宏定义之前的用法if (completionBlock)   {   completionBlock(arg1, arg2); }    // 宏定义之后的用法BLOCK_EXEC&#40;completionBlock, arg1, arg2&#41;;
  17. Debug栏打印时自动把Unicode编码转化成汉字
    // 有时候我们在xcode中打印中文,会打印出Unicode编码,还需要自己去一些在线网站转换,有了插件就方便多了。DXXcodeConsoleUnicodePlugin 插件
  18. 设置状态栏文字样式颜色
    [[UIApplication sharedApplication] setStatusBarHidden:NO];[[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleLightContent];
  19. 自动生成模型代码的插件
    // 可自动生成模型的代码,省去写模型代码的时间ESJsonFormat-for-Xcode
  20. iOS中的一些手势
    //轻击手势(TapGestureRecognizer)//轻扫手势(SwipeGestureRecognizer)//长按手势(LongPressGestureRecognizer)//拖动手势(PanGestureRecognizer)//捏合手势(PinchGestureRecognizer)//旋转手势(RotationGestureRecognizer)
  21. iOS 开发中一些相关的路径
    //模拟器的位置:/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs//文档安装位置:/Applications/Xcode.app/Contents/Developer/Documentation/DocSets//插件保存路径:~/Library/ApplicationSupport/Developer/Shared/Xcode/Plug-ins//自定义代码段的保存路径:~/Library/Developer/Xcode/UserData/CodeSnippets/ //如果找不到CodeSnippets文件夹,可以自己新建一个CodeSnippets文件夹。//证书路径~/Library/MobileDevice/Provisioning Profiles
  22. 获取 iOS 路径的方法
    //获取家目录路径的函数NSString *homeDir = NSHomeDirectory();//获取Documents目录路径的方法NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);NSString *docDir = [paths objectAtIndex:0];//获取Documents目录路径的方法NSArray *paths = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES);NSString *cachesDir = [paths objectAtIndex:0];//获取tmp目录路径的方法:NSString *tmpDir = NSTemporaryDirectory();
  23. 字符串相关操作
    //去除所有的空格[str stringByReplacingOccurrencesOfString:@" " withString:@""]//去除首尾的空格[str stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];- (NSString *)uppercaseString;// 全部字符转为大写字母- (NSString *)lowercaseString; //全部字符转为小写字母
  24. CocoaPods pod install/pod update更新慢的问题
    pod install --verbose --no-repo-update pod update --verbose --no-repo-update//如果不加后面的参数,默认会升级CocoaPods的spec仓库,加一个参数可以省略这一步,然后速度就会提升不少。
  25. 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
  26. 把tableview里cell的小对勾的颜色改成别的颜色
    _mTableView.tintColor = [UIColor redColor];
  27. 调整tableview的separaLine线的位置
    tableView.separatorInset = UIEdgeInsetsMake(0, 100, 0, 0);
  28. 设置滑动的时候隐藏navigation bar
    navigationController.hidesBarsOnSwipe = Yes;
  29. 自动处理键盘事件,实现输入框防遮挡的插件
    IQKeyboardManagerhttps://github.com/hackiftekhar/IQKeyboardManager
  30. Quartz2D相关
    //图形上下是一个CGContextRef类型的数据。//图形上下文包含://1,绘图路径(各种各样图形)//2,绘图状态(颜色,线宽,样式,旋转,缩放,平移)//3,输出目标(绘制到什么地方去?UIView、图片)//1,获取当前图形上下文CGContextRef ctx = UIGraphicsGetCurrentContext();//2,添加线条CGContextMoveToPoint(ctx, 20, 20);//3,渲染CGContextStrokePath(ctx);CGContextFillPath(ctx);//4,关闭路径CGContextClosePath(ctx);//5,画矩形CGContextAddRect(ctx, CGRectMake(20, 20, 100, 120));//6,设置线条颜色[[UIColor redColor] setStroke];//7, 设置线条宽度CGContextSetLineWidth(ctx, 20);//8,设置头尾样式CGContextSetLineCap(ctx, kCGLineCapSquare);//9,设置转折点样式CGContextSetLineJoin(ctx, kCGLineJoinBevel);//10,画圆CGContextAddEllipseInRect(ctx, CGRectMake(30, 50, 100, 100));//11,指定圆心CGContextAddArc(ctx, 100, 100, 50, 0, M_PI * 2, 1);//12,获取图片上下文UIGraphicsGetImageFromCurrentImageContext();//13,保存图形上下文CGContextSaveGState(ctx)//14,恢复图形上下文CGContextRestoreGState(cox)
  31. 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);
  32. 隐藏导航栏上的返回字体
    //SwiftUIBarButtonItem.appearance().setBackButtonTitlePositionAdjustment(UIOffsetMake(0, -60), forBarMetrics: .Default)//OC[[UIBarButtonItem appearance] setBackButtonTitlePositionAdjustment:UIOffsetMake(0, -60) forBarMetrics:UIBarMetricsDefault];
  33. 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]; }}
  34. 动态隐藏NavigationBar
    //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。//2.在滑动过程中隐藏//像safari//(1) self.navigationController.hidesBarsOnSwipe = YES;//(2)- (void)scrollViewDidScroll:(UIScrollView *)scrollView{CGFloat offsetY = scrollView.contentOffset.y + __tableView.contentInset.top;CGFloat panTranslationY = [scrollView.panGestureRecognizer translationInView:self.tableView].y;if (offsetY > 64) {if (panTranslationY > 0) { //下滑趋势,显示 [self.navigationController setNavigationBarHidden:NO animated:YES];} else { //上滑趋势,隐藏 [self.navigationController setNavigationBarHidden:YES animated:YES]; }} else {[self.navigationController setNavigationBarHidden:NO animated:YES]; }}//这里的offsetY > 64只是为了在视图滑过navigationBar的高度之后才开始处理,防止影响展示效果。panTranslationY是scrollView的pan手势的手指位置的y值,可能不是太好,因为panTranslationY这个值在较小幅度上下滑动时,可能都为正或都为负,这就使得这一方式不太灵敏.效果图
  35. 设置导航栏透明
    //方法一:设置透明度[[[self.navigationController.navigationBar subviews]objectAtIndex:0] setAlpha:0.1];//方法二:设置背景图片/*** 设置导航栏,使其透明**/- (void)setNavigationBarColor:(UIColor *)color targetController:(UIViewController *)targetViewController{//导航条的颜色 以及隐藏导航条的颜色targetViewController.navigationController.navigationBar.shadowImage = [[UIImage alloc]init]; 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 *theImage = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); [targetViewController.navigationController.navigationBar setBackgroundImage:theImage forBarMetrics:UIBarMetricsDefault];}
  36. 设置字体和行间距
    //设置字体和行间距 UILabel * lable = [[UILabel alloc]initWithFrame:CGRectMake(50, 100, 300, 200)]; lable.text = @"大家好,我是Frank_chun,在这里我们一起学习新的知识,总结我们遇到的那些坑,共同的学习,共同的进步,共同的努力,只为美好的明天!!!有问题一起相互的探讨--438637472!!!"; lable.numberOfLines = 0;lable.font = [UIFont systemFontOfSize:12];lable.backgroundColor = [UIColor grayColor]; [self.view addSubview:lable]; //设置每个字体之间的间距 //NSKernAttributeName 这个对象所对应的值是一个NSNumber对象(包含小数),作用是修改默认字体之间的距离调整,值为0的话表示字距调整是禁用的; NSMutableAttributedString * str = [[NSMutableAttributedString alloc]initWithString:lable.text attributes:@{NSKernAttributeName:@(5.0)}];//设置某写字体的颜色//NSForegroundColorAttributeName 设置字体颜色NSRange blueRange = NSMakeRange([[str string] rangeOfString:@"Frank_chun"].location, [[str string] rangeOfString:@"Frank_chun"].length); [str addAttribute:NSForegroundColorAttributeName value:[UIColor redColor] range:blueRange]; NSRange blueRange1 = NSMakeRange([[str string] rangeOfString:@"438637472"].location, [[str string] rangeOfString:@"438637472"].length);[str addAttribute:NSForegroundColorAttributeName value:[UIColor redColor] range:blueRange1];//设置每行之间的间距 //NSParagraphStyleAttributeName 设置段落的样式NSMutableParagraphStyle * par = [[NSMutableParagraphStyle alloc]init];[par setLineSpacing:20];//为某一范围内文字添加某个属性//NSMakeRange表示所要的范围,从0到整个文本的长度[str addAttribute:NSParagraphStyleAttributeName value:par range:NSMakeRange(0, lable.text.length)]; [lable setAttributedText:str];效果图
  37. 点击button倒计时
    //第一种方法//点击button倒计时#import "ViewController.h"@interface ViewController ()@property (nonatomic, strong) UIButton * timeButton;@property (nonatomic, strong) NSTimer * timer;@property (nonatomic, strong)UIButton * btn;@end@implementation ViewController{ NSInteger _time;}- (void)viewDidLoad {[super viewDidLoad]; _time = 5; self.btn = [UIButton buttonWithType:UIButtonTypeCustom]; _btn.backgroundColor = [UIColor orangeColor];[_btn setTitle:@"获取验证码" forState:UIControlStateNormal]; _btn.titleLabel.font = [UIFont systemFontOfSize:15];[_timeButton setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];[_btn addTarget:self action:@selector(btnAction:) forControlEvents:UIControlEventTouchUpInside];[self refreshButtonWidth]; [self.view addSubview:self.btn];}- (void)refreshButtonWidth{ CGFloat width = 0; if (_btn.enabled){width = 100; } else { width = 200;} _btn.center = CGPointMake(self.view.frame.size.width/2, 200);_btn.bounds = CGRectMake(0, 0, width, 40); //每次刷新,保证区域正确[_btn setBackgroundImage:[self imageWithColor:[UIColor orangeColor] andSize:_btn.frame.size] forState:UIControlStateNormal];[_btn setBackgroundImage:[self imageWithColor:[UIColor lightGrayColor] andSize:_btn.frame.size] forState:UIControlStateDisabled];}- (UIImage *)imageWithColor:(UIColor *)color andSize:(CGSize)aSize{CGRect rect = CGRectMake(0.0f, 0.0f, aSize.width, aSize.height); UIGraphicsBeginImageContext(rect.size);CGContextRef context = UIGraphicsGetCurrentContext(); CGContextSetFillColorWithColor(context, [color CGColor]); CGContextFillRect(context, rect);UIImage *image = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext();return image;}- (void)btnAction:(UIButton *)sender{sender.enabled = NO;[self refreshButtonWidth];[sender setTitle:[NSString stringWithFormat:@"获取验证码(%zi)", _time] forState:UIControlStateNormal]; _timer = [NSTimer scheduledTimerWithTimeInterval:0.1 target:self selector:@selector(timeDown) userInfo:nil repeats:YES];}- (void)timeDown{ _time --;if (_time == 0) {[_btn setTitle:@"重新获取" forState:UIControlStateNormal]; _btn.enabled = YES; [self refreshButtonWidth]; [_timer invalidate]; _timer = nil; _time = 5 ; return; } [_btn setTitle:[NSString stringWithFormat:@"获取验证码(%zi)", _time] forState:UIControlStateNormal];}//第二种方法#pragma mark -点击发送验证码- (void)sendMessage:(UIButton *)btn{if (self.phoneField.text.length == 0) { [self remindMessage:@"请输入正确的手机号"];}else{ __block int timeout=60; //倒计时时间 dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0); dispatch_source_t _timer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0,queue); dispatch_source_set_timer(_timer,dispatch_walltime(NULL, 0),1.0*NSEC_PER_SEC, 0);//每秒执行 dispatch_source_set_event_handler(_timer, ^{ if(timeout<=0){ //倒计时结束,关闭 dispatch_source_cancel(_timer); dispatch_async(dispatch_get_main_queue(), ^{ // 设置界面的按钮显示 根据自己需求设置 [btn setTitle:@"发送验证码" forState:UIControlStateNormal]; btn.userInteractionEnabled = YES; }); }else{ int seconds = timeout % 60;NSString *strTime = [NSString stringWithFormat:@"%d", seconds];if ([strTime isEqualToString:@"0"]) {strTime = [NSString stringWithFormat:@"%d",60];} dispatch_async(dispatch_get_main_queue(), ^{ //设置界面的按钮显示 根据自己需求设置 //NSLog(@"____%@",strTime);[UIView beginAnimations:nil context:nil];[UIView setAnimationDuration:1]; [btn setTitle:[NSString stringWithFormat:@"%@秒后重新发送",strTime] forState:UIControlStateNormal];[UIView commitAnimations]; btn.userInteractionEnabled = NO;});timeout--;} }); dispatch_resume(_timer);}
  38. UITextField默认占位符是居中显示,让其居上显示
    textField.contentVerticalAlignment = UIControlContentVerticalAlignmentTop;
  39. 解决同时按两个按钮进两个view的问题
    [button setExclusiveTouch:YES];
  40. 图片拉伸
    UIImage* img=[UIImage imageNamed:@"2.png"];//原图UIEdgeInsets edge=UIEdgeInsetsMake(0, 10, 0,10);//UIImageResizingModeStretch:拉伸模式,通过拉伸UIEdgeInsets指定的矩形区域来填充图片//UIImageResizingModeTile:平铺模式,通过重复显示UIEdgeInsets指定的矩形区域来填充图img= [img resizableImageWithCapInsets:edge resizingMode:UIImageResizingModeStretch];self.imageView.image=img;
  41. 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"];
  42. 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
  43. 去掉导航栏下边的黑线
    [self.navigationController.navigationBar setBackgroundImage:[[UIImage alloc] init] forBarMetrics:UIBarMetricsDefault];self.navigationController.navigationBar.shadowImage = [[UIImage alloc] init];
  44. 修改pagecontrol颜色
    _pageControl.currentPageIndicatorTintColor=SFQRedColor;_pageControl.pageIndicatorTintColor=SFQGrayColor;
  45. 去掉UITableView的section的粘性,使其不会悬停
    //有时候使用UITableView所实现的列表,会使用到section,但是又不希望它粘在最顶上而是跟随滚动而消失或者出现- (void)scrollViewDidScroll:(UIScrollView *)scrollView {  if (scrollView == _tableView) {      CGFloat sectionHeaderHeight = 36;    if (scrollView.contentOffset.y <= sectionHeaderHeight && scrollView.contentOffset.y >= 0) {          scrollView.contentInset = UIEdgeInsetsMake(-scrollView.contentOffset.y, 0, 0, 0);      } else if (scrollView.contentOffset.y >= sectionHeaderHeight) {          scrollView.contentInset = UIEdgeInsetsMake(-sectionHeaderHeight, 0, 0, 0);      }  }  }
  46. 通过2D仿射函数实现小的动画效果(变大缩小) --可用于自定义pageControl中
    [UIView animateWithDuration:0.3 animations:^{   imageView.transform = CGAffineTransformMakeScale(2, 2);   } completion:^(BOOL finished) {   imageView.transform = CGAffineTransformMakeScale(1.0, 1.0);   }];
  47. UIImage与字符串互转
    //图片转字符串  -(NSString *)UIImageToBase64Str:(UIImage *) image  {  NSData *data = UIImageJPEGRepresentation(image, 1.0f);  NSString *encodedImageStr = [data base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];  return encodedImageStr;  }//字符串转图片  -(UIImage *)Base64StrToUIImage:(NSString *)_encodedImageStr  {  NSData *_decodedImageData   = [[NSData alloc] initWithBase64Encoding:_encodedImageStr];  UIImage *_decodedImage      = [UIImage imageWithData:_decodedImageData];  return _decodedImage;  }
  48. 判断NSString中是否包含中文
    -(BOOL)isChinese:(NSString *)str{NSString *match=@"(^[\u4e00-\u9fa5]+$)";NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF matches %@", match];return [predicate evaluateWithObject:str];}
  49. NSDate与NSString的相互转化
    -(NSString *)dateToString:(NSDate *)date {// 初始化时间格式控制器NSDateFormatter *matter = [[NSDateFormatter alloc] init];// 设置设计格式[matter setDateFormat:@"yyyy-MM-dd hh:mm:ss zzz"];// 进行转换NSString *dateStr = [matter stringFromDate:date];return dateStr;}-(NSDate *)stringToDate:(NSString *)dateStr {// 初始化时间格式控制器NSDateFormatter *matter = [[NSDateFormatter alloc] init];// 设置设计格式[matter setDateFormat:@"yyyy-MM-dd hh:mm:ss zzz"];// 进行转换NSDate *date = [matter dateFromString:dateStr];return date;}


原创粉丝点击