1. 打印View所有子視圖

po [[self view]recursiveDescription]
2. layoutSubviews調用的調用時機
* 當視圖第一次顯示的時候會被調用* 當這個視圖顯示到屏幕上了,點擊按鈕* 添加子視圖也會調用這個方法* 當本視圖的大小發生改變的時候是會調用的* 當子視圖的frame發生改變的時候是會調用的* 當刪除子視圖的時候是會調用的
3. NSString過濾特殊字符
// 定義一個特殊字符的集合NSCharacterSet *set = [NSCharacterSet characterSetWithCharactersInString:@"@／：；（）￥「」＂、[]{}#%-*+=_//|~＜＞$€^?'@#$%^&*()_+'/""];// 過濾字符串的特殊字符NSString *newString = [trimString stringByTrimmingCharactersInSet:set];
4. TransForm屬性
//平移按鈕CGAffineTransform transForm = self.buttonView.transform;self.buttonView.transform = CGAffineTransformTranslate(transForm, 10, 0);//旋轉按鈕CGAffineTransform transForm = self.buttonView.transform;self.buttonView.transform = CGAffineTransformRotate(transForm, M_PI_4);//縮放按鈕self.buttonView.transform = CGAffineTransformScale(transForm, 1.2, 1.2);//初始化復位self.buttonView.transform = CGAffineTransformIdentity;
5. 去掉分割線多余15像素
首先在viewDidLoad方法加入以下代碼： if ([self.tableView respondsToSelector:@selector(setSeparatorInset:)]) {        [self.tableView setSeparatorInset:UIEdgeInsetsZero];    }    if ([self.tableView respondsToSelector:@selector(setLayoutMargins:)]) {                [self.tableView setLayoutMargins:UIEdgeInsetsZero];}然后在重寫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. 計算方法耗時時間間隔
// 獲取時間間隔#define TICK   CFAbsoluteTime start = CFAbsoluteTimeGetCurrent();#define TOCK   NSLog(@"Time: %f", CFAbsoluteTimeGetCurrent() - start)
7. Color顏色宏定義
// 隨機顏色#define RANDOM_COLOR [UIColor colorWithRed:arc4random_uniform(256) / 255.0 green:arc4random_uniform(256) / 255.0 blue:arc4random_uniform(256) / 255.0 alpha:1]// 顏色(RGB)#define RGBCOLOR(r, g, b) [UIColor colorWithRed:(r)/255.0f green:(g)/255.0f blue:(b)/255.0f alpha:1]// 利用這種方法設置顏色和透明值，可不影響子視圖背景色#define RGBACOLOR(r, g, b, a) [UIColor colorWithRed:(r)/255.0f green:(g)/255.0f blue:(b)/255.0f alpha:(a)]
8. Alert提示宏定義
#define Alert(_S_, ...) [[[UIAlertView alloc] initWithTitle:@"提示" message:[NSString stringWithFormat:(_S_), ##__VA_ARGS__] delegate:nil cancelButtonTitle:@"確定" otherButtonTitles:nil] show]
9. 讓iOS應用直接退出
- (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 快速求總和 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);
10. 修改Label中不同文字顏色
- (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為整體字符串, editStr為需要修改的字符串    NSRange range = [string rangeOfString:editStr];    NSMutableAttributedString *attribute = [[NSMutableAttributedString alloc] initWithString:string];    // 設置屬性修改字體顏色UIColor與大小UIFont    [attribute addAttributes:@{NSForegroundColorAttributeName:color} range:range];    self.label.attributedText = attribute;}
11. 播放聲音
  #import<AVFoundation>   //  1.獲取音效資源的路徑   NSString *path = [[NSBundle mainBundle]pathForResource:@"pour_milk" ofType:@"wav"];   //  2.將路勁轉化為url   NSURL *tempUrl = [NSURL fileURLWithPath:path];   //  3.用轉化成的url創建一個播放器   NSError *error = nil;   AVAudioPlayer *play = [[AVAudioPlayer alloc]initWithContentsOfURL:tempUrl error:&error];   self.player = play;   //  4.播放   [play play];
12. 檢測是否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>> ~/.lldbinit    echo target stop-hook add -o /"target stop-hook disable/" >> ~/.lldbinit下次重新運行項目，然后就不報錯了。
25. Label行間距
-（void）test{    NSMutableAttributedString *attributedString =       [[NSMutableAttributedString alloc] initWithString:self.contentLabel.text];    NSMutableParagraphStyle *paragraphStyle =  [[NSMutableParagraphStyle alloc] init];     [paragraphStyle setLineSpacing:3];    //調整行間距          [attributedString addAttribute:NSParagraphStyleAttributeName                          value:paragraphStyle                          range:NSMakeRange(0, [self.contentLabel.text length])];     self.contentLabel.attributedText = attributedString;}
26. UIImageView填充模式
@"UIViewContentModeScaleToFill",      // 拉伸自適應填滿整個視圖  @"UIViewContentModeScaleaspectFit",   // 自適應比例大小顯示  @"UIViewContentModeScaleAspectFill",  // 原始大小顯示  @"UIViewContentModeRedraw",           // 尺寸改變時重繪  @"UIViewContentModeCenter",           // 中間  @"UIViewContentModeTop",              // 頂部  @"UIViewContentModeBottom",           // 底部  @"UIViewContentModeLeft",             // 中間貼左  @"UIViewContentModeRight",            // 中間貼右  @"UIViewContentModeTopLeft",          // 貼左上  @"UIViewContentModeTopRight",         // 貼右上  @"UIViewContentModeBottomLeft",       // 貼左下  @"UIViewContentModeBottomRight",      // 貼右下
27. 宏定義檢測block是否可用
#define BLOCK_EXEC&#40;block, ...&#41; if (block) { block(__VA_ARGS__); };   // 宏定義之前的用法 if (completionBlock)   {       completionBlock(arg1, arg2);   }    // 宏定義之后的用法 BLOCK_EXEC&#40;completionBlock, arg1, arg2&#41;;
28. Debug欄打印時自動把Unicode編碼轉化成漢字
// 有時候我們在xcode中打印中文,會打印出Unicode編碼,還需要自己去一些在線網站轉換,有了插件就方便多了。 DXXcodeConsoleUnicodePlugin 插件
29. 設置狀態欄文字樣式顏色
[[UIApplication sharedApplication] setStatusBarHidden:NO];[[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleLightContent];
30. 自動生成模型代碼的插件
// 可自動生成模型的代碼，省去寫模型代碼的時間ESJsonFormat-for-Xcode
31. iOS中的一些手勢
輕擊手勢（TapGestureRecognizer）輕掃手勢（SwipeGestureRecognizer）長按手勢（LongPressGestureRecognizer）拖動手勢（PanGestureRecognizer）捏合手勢（PinchGestureRecognizer）旋轉手勢（RotationGestureRecognizer）
32. iOS 開發中一些相關的路徑
模擬器的位置:/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs 文檔安裝位置:/Applications/Xcode.app/Contents/Developer/Documentation/DocSets插件保存路徑:~/Library/ApplicationSupport/Developer/Shared/Xcode/Plug-ins自定義代碼段的保存路徑:~/Library/Developer/Xcode/UserData/CodeSnippets/ 如果找不到CodeSnippets文件夾，可以自己新建一個CodeSnippets文件夾。證書路徑~/Library/MobileDevice/Provisioning Profiles
33. 獲取 iOS 路徑的方法
獲取家目錄路徑的函數NSString *homeDir = NSHomeDirectory();獲取Documents目錄路徑的方法NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);NSString *docDir = [paths objectAtIndex:0];獲取Documents目錄路徑的方法NSArray *paths = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES);NSString *cachesDir = [paths objectAtIndex:0];獲取tmp目錄路徑的方法：NSString *tmpDir = NSTemporaryDirectory();
34. 字符串相關操作
去除所有的空格[str stringByReplacingOccurrencesOfString:@" " withString:@""]去除首尾的空格[str stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];- (NSString *)uppercaseString; 全部字符轉為大寫字母- (NSString *)lowercaseString 全部字符轉為小寫字母
35. CocoaPods pod install/pod update更新慢的問題
pod install --verbose --no-repo-update pod update --verbose --no-repo-update如果不加后面的參數，默認會升級CocoaPods的spec倉庫，加一個參數可以省略這一步，然后速度就會提升不少。
36. MRC和ARC混編設置方式
在XCode中targets的build phases選項下Compile Sources下選擇 不需要arc編譯的文件雙擊輸入 -fno-objc-arc 即可MRC工程中也可以使用ARC的類，方法如下：在XCode中targets的build phases選項下Compile Sources下選擇要使用arc編譯的文件雙擊輸入 -fobjc-arc 即可
37. 把tableview里cell的小對勾的顏色改成別的顏色
_mTableView.tintColor = [UIColor redColor];
38. 調整tableview的separaLine線的位置
tableView.separatorInset = UIEdgeInsetsMake(0, 100, 0, 0);
39. 設置滑動的時候隱藏navigationbar
navigationController.hidesBarsOnSwipe = Yes
40. 自動處理鍵盤事件，實現輸入框防遮擋的插件
IQKeyboardManagerhttps://github.com/hackiftekhar/IQKeyboardManager
41. Quartz2D相關
圖形上下是一個CGContextRef類型的數據。圖形上下文包含：1，繪圖路徑（各種各樣圖形）2，繪圖狀態（顏色，線寬，樣式，旋轉，縮放，平移）3，輸出目標（繪制到什么地方去？UIView、圖片）1，獲取當前圖形上下文CGContextRef ctx = UIGraphicsGetCurrentContext();2，添加線條CGContextMoveToPoint(ctx, 20, 20);3，渲染CGContextStrokePath(ctx);CGContextFillPath(ctx);4，關閉路徑CGContextClosePath(ctx);5，畫矩形CGContextAddRect(ctx, CGRectMake(20, 20, 100, 120));6，設置線條顏色[[UIColor redColor] setStroke];7， 設置線條寬度CGContextSetLineWidth(ctx, 20);8，設置頭尾樣式CGContextSetLineCap(ctx, kCGLineCapSquare);9，設置轉折點樣式CGContextSetLineJoin(ctx, kCGLineJoinBevel);10，畫圓CGContextAddEllipseInRect(ctx, CGRectMake(30, 50, 100, 100));11，指定圓心CGContextAddArc(ctx, 100, 100, 50, 0, M_PI * 2, 1);12，獲取圖片上下文UIGraphicsGetImageFromCurrentImageContext();13，保存圖形上下文CGContextSaveGState(ctx)14，恢復圖形上下文CGContextRestoreGState(ctx)
42. 屏幕截圖
    // 1. 開啟一個與圖片相關的圖形上下文    UIGraphicsBeginImageContextWithOptions(self.view.bounds.size,NO,0.0);    // 2. 獲取當前圖形上下文    CGContextRef ctx = UIGraphicsGetCurrentContext();    // 3. 獲取需要截取的view的layer    [self.view.layer renderInContext:ctx];    // 4. 從當前上下文中獲取圖片    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();    // 5. 關閉圖形上下文    UIGraphicsEndImageContext();    // 6. 把圖片保存到相冊    UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil);
43. 隱藏導航欄上的返回字體
//SwiftUIBarButtonItem.appearance().setBackButtonTitlePositionAdjustment(UIOffsetMake(0, -60), forBarMetrics: .Default)//OC[[UIBarButtonItem appearance] setBackButtonTitlePositionAdjustment:UIOffsetMake(0, -60) forBarMetrics:UIBarMetricsDefault];
44. 解決tableview的分割線短一截
-(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]; }}
45. 動態隱藏NavigationBar
//1.當我們的手離開屏幕時候隱藏- (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這個量，在上滑和下滑時，變化極小（小數），但是因為方向不同，有正負之分，這就很好處理了。
//2.在滑動過程中隱藏//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) { //下滑趨勢，顯示 [self.navigationController setNavigationBarHidden:NO animated:YES];} else { //上滑趨勢，隱藏 [self.navigationController setNavigationBarHidden:YES animated:YES]; }} else {[self.navigationController setNavigationBarHidden:NO animated:YES]; }}這里的offsetY > 64只是為了在視圖滑過navigationBar的高度之后才開始處理，防止影響展示效果。panTranslationY是scrollView的pan手勢的手指位置的y值，可能不是太好，因為panTranslationY這個值在較小幅度上下滑動時，可能都為正或都為負，這就使得這一方式不太靈敏.
效果圖
46. 設置導航欄透明
//方法一:設置透明度[[[self.navigationController.navigationBar subviews]objectAtIndex:0] setAlpha:0.1];//方法二:設置背景圖片/** * 設置導航欄,使其透明 **/- (void)setNavigationBarColor:(UIColor *)color targetController:(UIViewController *)targetViewController{//導航條的顏色 以及隱藏導航條的顏色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];}
47. 設置字體和行間距
//設置字體和行間距 UILabel * lable = [[UILabel alloc]initWithFrame:CGRectMake(50, 100, 300, 200)]; lable.text = @"大家好,我是Frank_chun,在這里我們一起學習新的知識,總結我們遇到的那些坑,共同的學習,共同的進步,共同的努力,只為美好的明天!!!有問題一起相互的探討--438637472!!!"; lable.numberOfLines = 0;lable.font = [UIFont systemFontOfSize:12];lable.backgroundColor = [UIColor grayColor]; [self.view addSubview:lable]; //設置每個字體之間的間距 //NSKernAttributeName 這個對象所對應的值是一個NSNumber對象(包含小數),作用是修改默認字體之間的距離調整,值為0的話表示字距調整是禁用的; NSMutableAttributedString * str = [[NSMutableAttributedString alloc]initWithString:lable.text attributes:@{NSKernAttributeName:@(5.0)}];//設置某寫字體的顏色//NSForegroundColorAttributeName 設置字體顏色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];//設置每行之間的間距 //NSParagraphStyleAttributeName 設置段落的樣式NSMutableParagraphStyle * par = [[NSMutableParagraphStyle alloc]init];[par setLineSpacing:20];//為某一范圍內文字添加某個屬性//NSMakeRange表示所要的范圍,從0到整個文本的長度[str addAttribute:NSParagraphStyleAttributeName value:par range:NSMakeRange(0, lable.text.length)]; [lable setAttributedText:str];
效果圖
48. 點擊button倒計時
//第一種方法//點擊button倒計時#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:@"獲取驗證碼" 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，保證區域正確[_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:@"獲取驗證碼(%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:@"重新獲取" forState:UIControlStateNormal]; _btn.enabled = YES; [self refreshButtonWidth]; [_timer invalidate]; _timer = nil; _time = 5 ; return; } [_btn setTitle:[NSString stringWithFormat:@"獲取驗證碼(%zi)", _time] forState:UIControlStateNormal];}
//第二種方法#pragma mark -點擊發送驗證碼- (void)sendMessage:(UIButton *)btn{if (self.phoneField.text.length == 0) { [self remindMessage:@"請輸入正確的手機號"];}else{ __block int timeout=60; //倒計時時間 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); //每秒執行 dispatch_source_set_event_handler(_timer, ^{ if(timeout<=0){ //倒計時結束，關閉 dispatch_source_cancel(_timer); dispatch_async(dispatch_get_main_queue(), ^{ // 設置界面的按鈕顯示 根據自己需求設置 [btn setTitle:@"發送驗證碼" 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(), ^{ //設置界面的按鈕顯示 根據自己需求設置 //NSLog(@"____%@",strTime);[UIView beginAnimations:nil context:nil];[UIView setAnimationDuration:1]; [btn setTitle:[NSString stringWithFormat:@"%@秒后重新發送",strTime] forState:UIControlStateNormal];[UIView commitAnimations]; btn.userInteractionEnabled = NO; }); timeout--; } }); dispatch_resume(_timer);}
效果圖
49. UITextField默認占位符是居中顯示,讓其居上顯示
textField.contentVerticalAlignment = UIControlContentVerticalAlignmentTop;
50. 解決同時按兩個按鈕進兩個view的問題
[button setExclusiveTouch:YES];
51. 圖片拉伸
UIImage* img=[UIImage imageNamed:@"2.png"];//原圖UIEdgeInsets edge=UIEdgeInsetsMake(0, 10, 0,10);//UIImageResizingModeStretch：拉伸模式，通過拉伸UIEdgeInsets指定的矩形區域來填充圖片//UIImageResizingModeTile：平鋪模式，通過重復顯示UIEdgeInsets指定的矩形區域來填充圖img= [img resizableImageWithCapInsets:edge resizingMode:UIImageResizingModeStretch];self.imageView.image=img;
52. 修改textFieldplaceholder字體顏色和大小
textField.placeholder = @"username is in here!";  [textField setValue:[UIColor redColor] forKeyPath:@"_placeholderLabel.textColor"];  [textField setValue:[UIFont boldSystemFontOfSize:16] forKeyPath:@"_placeholderLabel.font"];
53. 修改狀態欄字體顏色
只能設置兩種顏色，黑色和白色，系統默認黑色設置為白色方法：（1）在plist里面添加Status bar style，值為UIStatusBarStyleLightContent（白色）或UIStatusBarStyleDefault（黑 色）（2）在Info.plist中設置UIViewControllerBasedStatusBarAppearance 為NO
54. 去掉導航欄下邊的黑線
[self.navigationController.navigationBar setBackgroundImage:[[UIImage alloc] init] forBarMetrics:UIBarMetricsDefault];self.navigationController.navigationBar.shadowImage = [[UIImage alloc] init];
55. 修改pagecontrol顏色
_pageControl.currentPageIndicatorTintColor=SFQRedColor;_pageControl.pageIndicatorTintColor=SFQGrayColor;
56. 去掉UITableView的section的粘性，使其不會懸停
//有時候使用UITableView所實現的列表，會使用到section，但是又不希望它粘在最頂上而是跟隨滾動而消失或者出現- (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);          }      }  }
57. 通過2D仿射函數實現小的動畫效果(變大縮小) --可用于自定義pageControl中
[UIView animateWithDuration:0.3 animations:^{       imageView.transform = CGAffineTransformMakeScale(2, 2);       } completion:^(BOOL finished) {       imageView.transform = CGAffineTransformMakeScale(1.0, 1.0);       }];
58. UIImage與字符串互轉
//圖片轉字符串  -(NSString *)UIImageToBase64Str:(UIImage *) image  {      NSData *data = UIImageJPEGRepresentation(image, 1.0f);      NSString *encodedImageStr = [data base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];      return encodedImageStr;  }//字符串轉圖片  -(UIImage *)Base64StrToUIImage:(NSString *)_encodedImageStr  {      NSData *_decodedImageData   = [[NSData alloc] initWithBase64Encoding:_encodedImageStr];      UIImage *_decodedImage      = [UIImage imageWithData:_decodedImageData];      return _decodedImage;  }
59. 判斷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];}
60. NSDate與NSString的相互轉化
-(NSString *)dateToString:(NSDate *)date {  // 初始化時間格式控制器  NSDateFormatter *matter = [[NSDateFormatter alloc] init];  // 設置設計格式  [matter setDateFormat:@"yyyy-MM-dd hh:mm:ss zzz"];  // 進行轉換  NSString *dateStr = [matter stringFromDate:date];  return dateStr;}-(NSDate *)stringToDate:(NSString *)dateStr {  // 初始化時間格式控制器  NSDateFormatter *matter = [[NSDateFormatter alloc] init];  // 設置設計格式  [matter setDateFormat:@"yyyy-MM-dd hh:mm:ss zzz"];  // 進行轉換  NSDate *date = [matter dateFromString:dateStr];  return date;}