颜色块由外到内的闪动NSTimer ...-优快云博客

本文链接：https://blog.youkuaiyun.com/qq_32780047/article/details/50475667

本文介绍了一个使用Objective-C实现的iOS应用示例，该应用通过创建一系列不同大小的UIView，并随机分配颜色来展示视觉效果。同时，通过定时器周期性地改变视图的颜色，实现了动态变化的效果。


#import "RootViewController.h"

@interface RootViewController ()

@end

@implementation RootViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    //生成几个视图并为几个视图添加颜色(从大到小)
    for (NSInteger i = 7; i >= 1; i--) {
        //只要不出界就行
        UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 50 * i, 50 * i)];
        //视图颜色随机
        view.backgroundColor = [UIColor colorWithRed:arc4random() % 256 / 255. green:arc4random() % 256 / 255. blue:arc4random() % 256 / 255. alpha:1.0];
        //视图中心点是屏幕的中心点
        view.center = self.view.center;
        //视图tag值
        view.tag = 100 + i;
        [self.view addSubview:view];
        [view release];
    }

    //计时器, 调用改变颜色的函数
    [NSTimer scheduledTimerWithTimeInterval:.5 target:self selector:@selector(changeColor) userInfo:nil repeats:YES];
}

- (void)changeColor {
    //交换视图6次
    for (NSInteger i = 1; i <= 6; i++) {
        UIView *view1 = (UIView *)[self.view viewWithTag:100 + i];
        UIView *view2 = (UIView *)[self.view viewWithTag:100 + i + 1];
        //大的赋给小的
        view1.backgroundColor = view2.backgroundColor;
    }

    //大的再随机产生颜色view
    UIColor *color = [UIColor colorWithRed:arc4random() % 256 / 255. green:arc4random() % 256 / 255. blue:arc4random() % 256 / 255. alpha:1.0];
    UIView *view = (UIView *)[self.view viewWithTag:107];
    view.backgroundColor = color;
}