1、假如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、判别设备是iphone仍是iphone4的代码：
#define isRetina ([UIScreen instancesRespondToSelector:@selector(currentMode)] ? CGSizeEqualToSize(CGSizeMake(640, 960), [[UIScreen mainScreen] currentMode].size) : NO)
3、判别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、怎么把当时的视图作为相片保存到相册中去：
#import
UIGraphicsBeginImageContext(currentView.bounds.size); //currentView 当时的view
[currentView.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIImageWriteToSavedPhotosAlbum(viewImage, nil, nil, nil);
5、本地告诉(类似于push告诉)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通话事情：
CTCallCenter *center = [[CTCallCenter alloc] init];
center.callEventHandler = ^(CTCall *call)
{
NSLog(@call:%@, call.callState);
}
7、iOS 4 引入了多任务支撑，所以用户按下 “Home” 键今后程序或许并没有退出而是转入了后台运转。假如您想让使用直接退出，最简略的办法是：在 info-plist 里边找到 Application does not run in background 一项，勾选即可。
8、使UIimageView的图画旋转：
float rotateAngle = M_PI;
CGAffineTransform transform =CGAffineTransformMakeRotation(rotateAngle);
imageView.transform = transform;
9、设置旋转的原点：
#import
UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@bg.png]];
imageView.layer.anchorPoint = CGPointMake(0.5, 1.0);
10、完成自界说的状态栏(隐瞒状态栏)：
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、在程序中完成电话的拨打：
//增加电话图标按钮
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
//界说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的键盘色彩：
