一个实现图片放大缩小的笨办法

#import "UITestAppAppDelegate.h"

@implementation UITestAppAppDelegate

@synthesize window;
@synthesize img;

- (void) applicationDidFinishLaunching:(UIApplication *)application{
    CGRect frame = CGRectMake(80, 100, 80, 120);
    img = [[UIImageView alloc] initWithFrame:frame];
    [img setImage:[UIImage imageNamed:@"4.png"]];
    [window addSubview:img];
    [window makeKeyAndVisible];    
}
-(IBAction) increaseSizeButtonPressed{
    CGRect newframe = CGRectMake(20, 50, 240, 360);
    img = [[UIImageView alloc] initWithFrame:newframe];
    [img setImage:[UIImage imageNamed:@"4.png"]];
    img.frame = newframe;
    [window addSubview:img];
}
-(IBAction) decreaseSizeButtonPressed{
    CGRect newframe = CGRectMake(0, 0, 32, 48);
     img = [[UIImageView alloc] initWithFrame:newframe];
    [img setImage:[UIImage imageNamed:@"4.png"]];
    [window addSubview:img];
    img.frame = newframe;
}
- (void)dealloc {
    [img release];
    [window release];
    [super dealloc];
}


@end