适合所有尺寸打印马赛克

    CGFloat width = 40;
    CGFloat height = 40;
    
    //获取屏幕宽高
    //获取屏幕对象
    UIScreen *screen = [UIScreen mainScreen];
    //获取屏幕大小
    CGRect screenFrame = [screen bounds];
    //单独取出屏幕的宽高
//    CGFloat screenWidth = screenFrame.size.width;
    CGFloat screenWidth = CGRectGetWidth(screenFrame);
    
//    CGFloat screenHeight = screenFrame.size.height;
    CGFloat screenHeight = CGRectGetHeight(screenFrame);
//          x轴              y轴
//    CGRectGetMinX  +   CGRectGetMinY   =   view的左上角坐标
//    CGRectGetMidX  +   CGRectGetMidY   =   view的中心坐标
//    CGRectGetMaxX  +   CGRectGetMaxY   =   view的右上角坐标
//    CGRectGetWidth +   CGRectGetHeight =   view的大小
    
    /*
(minx/y)  (midx/0) (maxx,y)
     +-----.-----+
     |           |
     .     .     .   (midx, midy)
     |           |
     +-----.-----+
     */
    
    
    //计算每一列的个数
    CGFloat col = screenWidth / width;
    //计算每一行的个数
    CGFloat row = screenHeight / height;
    
    
    for (NSInteger i = 0; i < row; ++i)
    {
        for (NSInteger j = 0; j < col; ++j)
        {
            UIView *v = [[UIView alloc] init];
            
            //设置第i行，第j列个view的大小
            v.frame = CGRectMake(j * width, i * height, width, height);
            
            //CGRectGetMidX(v.frame);
            //(v.frame.origin.x + v.frame.size.width) / 2;
            //CGRectGetMidY(v.frame);
            //(v.frame.origin.y + v.frame.size.height) / 2;
            //设置颜色
            v.backgroundColor = [UIColor colorWithRed:arc4random() % 256 / 255.0 green:arc4random() % 256 / 255.0 blue:arc4random() % 256 / 255.0 alpha:1];
            //放到窗口显示
            [self.window addSubview:v];
        }
    }