如何在iphone中实现图片的放大（不使用多点触控：即两个手指拉开）

Question

现在想在iphone中实现iphone的图片放大功能，将一张小图片放大到手机全屏这样一个动画效果，我想用calayer来实现，可是对它不太熟，请熟悉的朋友帮帮忙。很急。多谢了。

Answer 1

请参照代码#import <UIKit/UIKit.h>#define IMAGE_VIEW_1 100
#define IMAGE_VIEW_2 101#define BIGRECT CGRectMake(0.0f, 0.0f, 320.0f, 435.0f)
#define SMALLRECT CGRectMake(130.0f, 187.0f, 60.0f, 60.0f) @interface ToggleView: UIView
{
BOOL isOne;
}
@end@implementation ToggleView- (id) initWithFrame: (CGRect) aFrame;
{
self = [super initWithFrame:aFrame];

// Load both views, make them non-interactive
UIImageView *imgView1 = [[UIImageView alloc] initWithFrame:BIGRECT];
imgView1.image = [UIImage imageNamed:@"one.png"];
imgView1.userInteractionEnabled = NO;
imgView1.tag = IMAGE_VIEW_1; UIImageView *imgView2 = [[UIImageView alloc] initWithFrame:SMALLRECT];
imgView2.image = [UIImage imageNamed:@"two.png"];
imgView2.userInteractionEnabled = NO;
imgView2.tag = IMAGE_VIEW_2;

// image 1 is in front of image 2 to begin
[self addSubview:imgView2];
[self addSubview:imgView1]; 
isOne = YES;

[imgView1 release];
[imgView2 release]; return self;
}- (void) touchesBegan:(NSSet*)touches withEvent:(UIEvent*)event
{
// Determine which view occupies which role
UIImageView *big = (UIImageView *)[self viewWithTag: (isOne ? IMAGE_VIEW_1 : IMAGE_VIEW_2)];
UIImageView *little = (UIImageView *)[self viewWithTag: (isOne ? IMAGE_VIEW_2 : IMAGE_VIEW_1)];
isOne = !isOne;

// Pack all the changes into the animation block
CGContextRef context = UIGraphicsGetCurrentContext();
[UIView beginAnimations:nil context:context];
[UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];
[UIView setAnimationDuration:1.0]; [big setFrame:SMALLRECT];
[big setAlpha:0.5];
[little setFrame:BIGRECT];
[little setAlpha:1.0];

[UIView commitAnimations];

// Hide the shrunken "big" image.
[big setAlpha:0.0f];
[[big superview] bringSubviewToFront:big];
}
@end@interface HelloController : UIViewController
@end@implementation HelloController
- (void)loadView
{
ToggleView *contentView = [[ToggleView alloc] initWithFrame:[[UIScreen mainScreen] applicationFrame]];
contentView.backgroundColor = [UIColor whiteColor];
self.view = contentView;
    [contentView release];
}
@end
@interface SampleAppDelegate : NSObject <UIApplicationDelegate> 
@end@implementation SampleAppDelegate
- (void)applicationDidFinishLaunching:(UIApplication *)application {
UIWindow *window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
HelloController *hello = [[HelloController alloc] init];
[window addSubview:hello.view];
[window makeKeyAndVisible];
}
@endint main(int argc, char *argv[])
{
NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
int retVal = UIApplicationMain(argc, argv, nil, @"SampleAppDelegate");
[pool release];
return retVal;
}

Answer 2

http://blog.csdn.net/cloudhsu/archive/2010/08/26/5841089.aspx
该范例相关资料可到我的博客参考