学习UI编程已经有三四天了，这几天学习了一些初级的视图和控件，比如UIView,UIlabel以及UIButton.，学习UI编程,有一点乐趣就是自己写的代码可以看到效果了。这一点和C语言以及OC区别很大。于是我就尝试做了一个简单视图颜色变换的应用，也就是霓虹灯。实现的功能可以由里而外，也可以由外到里，还可以暂停。由于水平有限，再加上还没有学习NSTimer，只是从网上了解到了简单地应用，所以代码实现上可能会有些问题，算法不是最优的，还望大神们批评指点。贴上一张截图：

下面附上代码实现：

#import "ZZAppDelegate.h"

@interface ZZAppDelegate ()
{
    UIView *_containerView;
    NSTimer *_timer;
}
@end
@implementation ZZAppDelegate

- (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 grayColor];
    _containerView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 568)];
    _containerView.backgroundColor = [UIColor clearColor];
    [self.window addSubview:_containerView];
    [_containerView release];
    // 视图布局
    NSArray *array = [NSArray arrayWithObjects:[UIColor redColor], [UIColor orangeColor], [UIColor yellowColor], [UIColor greenColor], [UIColor blueColor], [UIColor cyanColor], [UIColor purpleColor], nil];

        for (int i = 0; i < 7; i++) {
            UIView *view = [[UIView alloc] initWithFrame:CGRectMake(20 + i * 20, 120 + i * 20, 280 - i * 40, 280 - i * 40)];
            view.backgroundColor = array[i];
            view.tag = i + 200;
            NSLog(@"%ld", (long)view.tag);
            [_containerView addSubview:view];
            [view release];
        }
    // 创建由内而外按钮
    UIButton *button1 = [UIButton buttonWithType:UIButtonTypeSystem
                         ];
    button1.frame = CGRectMake(40, 450, 70, 40);
    button1.backgroundColor = [UIColor cyanColor];
    [button1 setTitle:@"由内而外" forState:UIControlStateNormal];
    [button1 addTarget:self action:@selector(changeFromInToOut) forControlEvents:UIControlEventTouchUpInside];
    button1.layer.cornerRadius = 7;
    [_containerView addSubview:button1];
    // 创建停止按钮
    UIButton *button2 = [UIButton buttonWithType:UIButtonTypeSystem
                        ];
    button2.frame = CGRectMake(125, 450, 70, 40);
    button2.backgroundColor = [UIColor cyanColor];
    [button2 setTitle:@"停止" forState:UIControlStateNormal];
    [button2 addTarget:self action:@selector(stop) forControlEvents:UIControlEventTouchUpInside];
    button2.layer.cornerRadius = 7;
    [_containerView addSubview:button2];
    // 创建由外而内按钮
    UIButton *button3 = [UIButton buttonWithType:UIButtonTypeSystem
                         ];
    button3.frame = CGRectMake(210, 450, 70, 40);
    button3.backgroundColor = [UIColor cyanColor];
    [button3 setTitle:@"由外而内" forState:UIControlStateNormal];
    [button3 addTarget:self action:@selector(changeFromOutToIn) forControlEvents:UIControlEventTouchUpInside];
    button3.layer.cornerRadius = 7;
    [_containerView addSubview:button3];
    [self.window makeKeyAndVisible];
    return YES;
}
// 由内而外按钮触发事件
- (void)changeFromInToOut
{
    _timer = [NSTimer scheduledTimerWithTimeInterval:0.3 target:self selector:@selector(changeInToOut) userInfo:nil repeats:YES];
}
// 由外而内按钮出触发事件
- (void)changeFromOutToIn
{
    _timer = [NSTimer scheduledTimerWithTimeInterval:0.3 target:self selector:@selector(changeOutToIn) userInfo:nil repeats:YES];
}
// 暂停计时器
- (void)stop
{
    [_timer invalidate];
}
// 由内而外循环交换颜色
- (void)changeInToOut
{
    UIView *temp = [[UIView alloc] init];
    int i = 200;
    temp.backgroundColor = [_containerView viewWithTag:200].backgroundColor;
    for (i = 200; i < 207; i++) {
        [_containerView viewWithTag:i].backgroundColor = [_containerView viewWithTag: i + 1].backgroundColor;
    }
    [_containerView viewWithTag:206].backgroundColor =temp.backgroundColor;
    [temp release];
}
// 由外而内循环交换颜色
- (void)changeOutToIn
{
    UIView *temp = [[UIView alloc] init];
    int i = 206;
    temp.backgroundColor = [_containerView viewWithTag:206].backgroundColor;
    for (i = 206; i >= 0; i--) {
        [_containerView viewWithTag:i].backgroundColor = [_containerView viewWithTag: i - 1].backgroundColor;
    }
    [_containerView viewWithTag:200].backgroundColor =temp.backgroundColor;
    [temp release];
}

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