在RootViewController.m文件中

- (void)viewDidLoad//视图加载方法

- (void)viewDidLoad{        //设置红色    UIView *viewRed = [[UIView alloc]initWithFrame:CGRectMake(100, 100, 120, 30)];    viewRed.backgroundColor = [UIColor redColor];    [self.view addSubview:viewRed];        //设置橙色    UIView *viewOrange = [[UIView alloc]initWithFrame:CGRectMake(100, 130, 120, 30)];    viewOrange.backgroundColor = [UIColor orangeColor];    [self.view addSubview:viewOrange];        //设置黄色       UIView *viewYellow = [[UIView alloc]initWithFrame:CGRectMake(100, 160, 120, 30)];    viewYellow.backgroundColor = [UIColor yellowColor];    [self.view addSubview:viewYellow];        //设置绿色    UIView *viewGreen = [[UIView alloc]initWithFrame:CGRectMake(100, 190, 120, 30)];    viewGreen.backgroundColor = [UIColor greenColor];    [self.view addSubview:viewGreen];        //设置青色    UIView *viewGray = [[UIView alloc]initWithFrame:CGRectMake(100, 220, 120, 30)];    viewGray.backgroundColor = [UIColor grayColor];    [self.view addSubview:viewGray];        //设置蓝色    UIView *viewBlue = [[UIView alloc]initWithFrame:CGRectMake(100, 250, 120, 30)];    viewBlue.backgroundColor = [UIColor blueColor];    [self.view addSubview:viewBlue];    //设置紫色    UIView *viewPurple = [[UIView alloc]initWithFrame:CGRectMake(100, 280, 120, 30)];    viewPurple.backgroundColor = [UIColor purpleColor];    [self.view addSubview:viewPurple];        //设置按钮    UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];    button.frame = CGRectMake(100, 330, 120, 30);    [button setTitle:@"开始" forState:UIControlStateNormal];    button.backgroundColor = [UIColor blackColor];    button.tag = 108;    [button addTarget:self action:@selector(btnAction:) forControlEvents:UIControlEventTouchUpInside];    [self.view addSubview:button];        [super viewDidLoad];    // Do any additional setup after loading the view.}

在关联方法btnAction中：

 timer为全局变量

 可以在RootViewController.h文件中定义；

-(void)btnAction:(id)sender{    UIButton *button = (UIButton*)sender;    if (button.tag ==108) {        timer = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(doChangeColor:) userInfo:nil repeats:YES];        [timer fire];//计时器开始    }    }

在关联方法doChangeColor中：

-(void)doChangeColor:(id)sender{    NSArray *arr = self.view.subviews;//得到所有的视图    int count = [arr count]-1;//得到计数    UIView *firstView = [arr objectAtIndex:0];    UIColor *firstColor = firstView.backgroundColor;        for (int i=0; i

结果显示:

 

 会不断的改变背景图片，和实现了霓虹灯的效果。