九宫格算法分析:
//添加应用信息
//0.总列数(一行最多3列)
int totalColums = 3;
//1.应用的尺寸
CGFloat appW = 85;
CGFloat appH = 90;
//2.间隙 = (控制器View的宽度 - 3 * 应用宽度)/4
CGFloat marginX = (self.view.frame.size.width - totalColums * 85) / (totalColums+1); //X的间距
CGFloat marginY = 20; //Y的间距
//3.根据应用个数创建对应的框框
for (int index = 0; index<self.apps.count; index++) {
//3.1创建小框框
UIView *appView = [[UIView alloc]init];
//设置背景色
appView.backgroundColor = [UIColor redColor];
//3.2计算框框的位置
//计算行号和列号
int row = index / totalColums;
int col = index % totalColums;
CGFloat appX = marginX + col * (appW + marginX);
CGFloat appY = 30 + row * (appH + marginY);
appView.frame = CGRectMake(appX, appY, appW, appH);
//3.3添加框框到控制器的View
[self.view addSubview:appView];