UI_霓虹灯

AppDelegate.h

#import <UIKit/UIKit.h>@interface AppDelegate : UIResponder <UIApplicationDelegate>@property (strong, nonatomic) UIWindow *window;@end

AppDelegate.m

import "AppDelegate.h"@interface AppDelegate (){UIView *view1;UIView *view2;UIView *view3;UIView *view4;}@end@implementation AppDelegate- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];    // Override point for customization after application launch.    self.window.backgroundColor = [UIColor whiteColor];    [self.window makeKeyAndVisible];    //  build four different colors of the view        view1 = [[UIView alloc] initWithFrame:CGRectMake(100, 100, 200, 200)];        view1.backgroundColor = [UIColor blueColor];        [self.window addSubview:view1];        [view1 release];        view2 = [[UIView alloc] initWithFrame:CGRectMake(20, 20, 160, 160)];        view2.backgroundColor = [UIColor cyanColor];        [view1 addSubview:view2];        [view2 release];        view3 = [[UIView alloc] initWithFrame:CGRectMake(20, 20, 120, 120)];        view3.backgroundColor = [UIColor yellowColor];        [view2 addSubview:view3];        [view3 release];        view4 = [[UIView alloc] initWithFrame:CGRectMake(20, 20, 80, 80)];        view4.backgroundColor = [UIColor grayColor];        [view3 addSubview:view4];        [view4 release];    //  use the timer    [NSTimer scheduledTimerWithTimeInterval:0.5 target:self selector:@selector(going) userInfo:nil repeats:YES];    return YES;}//  with an intermediate variable handed on color- (void)going {    UIView *tempView = [[UIView alloc] init];    tempView.backgroundColor = view1.backgroundColor;    view1.backgroundColor = view2.backgroundColor;    view2.backgroundColor = view3.backgroundColor;    view3.backgroundColor = view4.backgroundColor;    view4.backgroundColor = tempView.backgroundColor;}