iOS开发 创建九宫格按钮布局

我的九宫格

 CGFloat btnWidth = (self.view.frame.size.width - 80)/3;
    for (int i = 0; i<9; i++) {
        NSInteger colunm = i%3; //取余
        NSInteger row = i/3;//整除
        UIButton * btn = [[UIButton alloc]initWithFrame:CGRectMake(20+colunm * (btnWidth+20), 200+row * (btnWidth+20), btnWidth, btnWidth)];
        btn.tag = i;
        btn.backgroundColor = [UIColor orangeColor];
        [self.view addSubview:btn];
        [btn addTarget:self action:@selector(btnClicks:) forControlEvents:UIControlEventTouchUpInside];
    }