背景颜色的随机显示

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    
    self.title=@"背景颜色的随机显示";
    
    CGFloat red = (CGFloat)arc4random() / 0x100000000;
    CGFloat green = (CGFloat)arc4random() / 0x100000000;
    CGFloat blue = (CGFloat)arc4random() / 0x100000000;
    self.view.backgroundColor = [UIColor colorWithRed:red green:green blue:blue alpha:1.0f];

}