UI：改变UIView背景颜色

//每隔一秒改变一次颜色

    [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(changeColor) userInfo:nil repeats:YES];

#pragma mark 改变颜色

- (void)changeColor{

    //动画开始

    [UIView beginAnimations:nil context:nil];

    [UIView setAnimationDuration:0.5];

    self.view.backgroundColor = [[UIColor alloc]initWithRed:(double)(arc4random()%256)/256 green:(double)(arc4random()%256)/256 blue:(double)(arc4random()%256)/256 alpha:0.5];

    //动画结束

    [UIView commitAnimations];

}

UI：改变UIView背景颜色

原文：http://blog.csdn.net/ytuzhangziyao/article/details/42171401