利用UIView做出霓虹灯的效果

@interface AppDelegate ()

@end

@implementation AppDelegate

- (void)dealloc
{
[_window release];
[super dealloc];
}

- (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];
[_window release];

// 定义view,颜色模块
UIView *view1 = [[UIView alloc] initWithFrame:CGRectMake(20, 20, 340, 340)];
view1.backgroundColor = [UIColor greenColor];
[self.window addSubview:view1];
[view1 release];
view1.tag = 1;

UIView *view2 = [[UIView alloc] initWithFrame:CGRectMake(40, 40, 300, 300)];
view2.backgroundColor = [UIColor purpleColor];
[self.window addSubview:view2];
[view2 release];
view2.tag = 2;

UIView *view3 = [[UIView alloc] initWithFrame:CGRectMake(60, 60, 260, 260)];
view3.backgroundColor = [UIColor magentaColor];
[self.window addSubview:view3];
[view3 release];
view3.tag = 3;

UIView *view4 = [[UIView alloc] initWithFrame:CGRectMake(80, 80, 220, 220)];
view4.backgroundColor = [UIColor redColor];
[self.window addSubview:view4];
[view4 release];
view4.tag = 4;

UIView *view5 = [[UIView alloc] initWithFrame:CGRectMake(100, 100, 180, 180)];
view5.backgroundColor = [UIColor orangeColor];
[self.window addSubview:view5];
[view5 release];
view5.tag = 5;

UIView *view6 = [[UIView alloc] initWithFrame:CGRectMake(120, 120, 140, 140)];
view6.backgroundColor = [UIColor yellowColor];
[self.window addSubview:view6];
[view6 release];
view6.tag = 6;

UIView *view7 = [[UIView alloc] initWithFrame:CGRectMake(140, 140, 100, 100)];
view7.backgroundColor = [UIColor cyanColor];
[self.window addSubview:view7];
[view7 release];
view7.tag = 7;

// 定义一个timer,实现色块变化
NSTimer *timer = [NSTimer scheduledTimerWithTimeInterval:0.3 target:self selector:@selector(changeColor) userInfo:nil repeats:YES];

return YES;
}

- (void)changeColor
{
// 定义一个color来接收7的颜色
UIColor *color = [self.window viewWithTag:7].backgroundColor;
// 换颜色
for (int i = 6 ; i > 0; i--) {
[self.window viewWithTag:i + 1].backgroundColor = [self.window viewWithTag:i ].backgroundColor;
}
// 最里面给最外面
[self.window viewWithTag:1].backgroundColor = color;
}
@end