1、如果在程序中想对某张图片进行处理的话(得到某张图片的一部分)可一用以下代码: UIImage *image = [UIImage imageNamed:filename]; CGImageRef imageRef = image.CGImage; CGRect rect = CGRectMake(origin.x, origin.y ,size.width, size.height); CGImageRef imageRefRect = CGImageCreateWithImageInRect(imageRef, rect); UIImage *imageRect = [[UIImage alloc] initWithCGImage:imageRefRect]; 2、判断设备是iphone还是iphone4的代码: #define isRetina ([UIScreen instancesRespondToSelector:@selector(currentMode)] ? CGSizeEqualToSize(CGSizeMake(640, 960), [[UIScreen mainScreen] currentMode].size) : NO) 3、判断邮箱输入的是否正确: - (BOOL) validateEmail: (NSString *) candidate { NSString *emailRegex = @"[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,4}"; NSPredicate *emailTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", emailRegex]; return [emailTest evaluateWithObject:candidate]; } 4、如何把当前的视图作为照片保存到相册中去: #import <QuartzCore/QuartzCore.h> UIGraphicsBeginImageContext(currentView.bounds.size); //currentView 当前的view [currentView.layer renderInContext:UIGraphicsGetCurrentContext()]; UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); UIImageWriteToSavedPhotosAlbum(viewImage, nil, nil, nil); 5、本地通知(类似于push通知)按home键到后台 十秒后触发: UILocalNotification *notification=[[UILocalNotification alloc] init]; if (notification!=nil) { NSLog(@">> support local notification"); NSDate *now=[NSDate new]; notification.fireDate=[now addTimeInterval:10]; notification.timeZone=[NSTimeZone defaultTimeZone]; notification.alertBody=@"该去吃晚饭了!"; [[UIApplication sharedApplication].scheduleLocalNotification:notification]; } 6、捕获iphone通话事件: CTCallCenter *center = [[CTCallCenter alloc] init]; center.callEventHandler = ^(CTCall *call) { NSLog(@"call:%@", call.callState); } 7、iOS 4 引入了多任务支持,所以用户按下 “Home” 键以后程序可能并没有退出而是转入了后台运行。如果您想让应用直接退出,最简单的方法是:在 info-plist 里面找到 Application does not run in background 一项,勾选即可。 8、使UIimageView的图像旋转: float rotateAngle = M_PI; CGAffineTransform transform =CGAffineTransformMakeRotation(rotateAngle); imageView.transform = transform; 9、设置旋转的原点: #import <QuartzCore/QuartzCore.h> UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"bg.png"]]; imageView.layer.anchorPoint = CGPointMake(0.5, 1.0); 10、实现自定义的状态栏(遮盖状态栏): CGRect frame = {{0, 0}, {320, 20}}; UIWindow* wd = [[UIWindow alloc] initWithFrame:frame]; [wd setBackgroundColor:[UIColor clearColor]]; [wd setWindowLevel:UIWindowLevelStatusBar]; frame = CGRectMake(100, 0, 30, 20); UIImageView* img = [[UIImageView alloc] initWithFrame:frame]; [img setContentMode:UIViewContentModeCenter]; [img setImage:[UIImage imageNamed:@"00_0103.png"]]; [wd addSubview:img]; [wd makeKeyAndVisible]; [UIView beginAnimations:nil context:nil]; [UIView setAnimationDuration:2]; frame.origin.x += 150; [img setFrame:frame]; [UIView commitAnimations]; 11、在程序中实现电话的拨打: //添加电话图标按钮 UIButton *btnPhone = [[UIButton buttonWithType:UIButtonTypeCustom] retain]; btnPhone.frame = CGRectMake(280,10,30,30); UIImage *image = [UIImage imageNamed:@"phone.png"]; [btnPhone setBackgroundImage:image forState:UIControlStateNormal]; //点击拨号按钮直接拨号 [btnPhone addTarget:self action:@selector(callAction:event:)forControlEvents:UIControlEventTouchUpInside]; [cell.contentView addSubview:btnPhone]; //cell是一个UITableViewCell //定义点击拨号按钮时的操作 - (void)callAction:(id)sender event:(id)event{ NSSet *touches = [event allTouches]; UITouch *touch = [touches anyObject]; CGPoint currentTouchPosition = [touch locationInView:self.listTable]; NSIndexPath *indexPath = [self.listTable indexPathForRowAtPoint: currentTouchPosition]; if (indexPath == nil) { return; } NSInteger section = [indexPath section]; NSUInteger row = [indexPath row]; NSDictionary *rowData = [datas objectAtIndex:row]; NSString *num = [[NSString alloc] initWithFormat:@"tel://%@",number]; //number为号码字符串 [[UIApplication sharedApplication] openURL:[NSURL URLWithString:num]]; //拨号 } 12、更改iphone的键盘颜色: 1.只有这2种数字键盘才有效果。UIKeyboardTypeNumberPad,UIKeyboardTypePhonePad 2. keyboardAppearance = UIKeyboardAppearanceAlert - (void)textViewDidBeginEditing:(UITextView *)textView{ NSArray *ws = [[UIApplication sharedApplication] windows]; for(UIView *w in ws){ NSArray *vs = [w subviews]; for(UIView *v in vs) { if([[NSString stringWithUTF8String:object_getClassName(v)] isEqualToString:@"UIKeyboard"]) { v.backgroundColor = [UIColor redColor]; } } } 13、设置时区 NSTimeZone *defaultTimeZone = [NSTimeZone defaultTimeZone]; NSTimeZone *tzGMT = [NSTimeZone timeZoneWithName:@"GMT"]; [NSTimeZone setDefaultTimeZone:tzGMT]; 上面两个时区任意用一个。 14、Ipad隐藏键盘的同时触发方法。 [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillHide:) name:UIKeyboardWillHideNotification object:nil]; - (IBAction)keyboardWillHide:(NSNotification *)note 14、在一个程序中打开另一个程序的方法。 http://www.cocoachina.com/iphonedev/sdk/2010/0322/768.html 15、计算字符串的字数 -(int)calculateTextNumber:(NSString *)text { float number = 0.0; int index = 0; for (index; index < [text length]; index++) { NSString *protoText = [text substringToIndex:[text length] - index]; NSString *toChangetext = [text substringToIndex:[text length] -1 -index]; NSString *charater; if ([toChangetext length]==0) { charater = protoText; } else { NSRange range = [text rangeOfString:toChangetext]; charater = [protoText stringByReplacingCharactersInRange:range withString:@""]; } NSLog(charater); if ([charater lengthOfBytesUsingEncoding:NSUTF8StringEncoding] == 3) { number++; } else { number = number+0.5; } } return ceil(number); }