类似美团的多级选择列表 － 简单易用

(史上最简洁的 三级列表 ，并且很容易改造成两级和一级或者四级,实现代码不超过550行);



初始化对象

``` OC
WSDropMenuView *dropMenu = [[WSDropMenuView alloc] initWithFrame:CGRectMake(0, 60, self.view.frame.size.width, 40)];
dropMenu.dataSource = self;
dropMenu.delegate  =self;
[self.view addSubview:dropMenu];  


```


实现代理方法 (简单易用 ， 不繁琐)
```OC


- (NSInteger)dropMenuView:(WSDropMenuView *)dropMenuView numberWithIndexPath:(WSIndexPath *)indexPath; //dataSource


- (NSString *)dropMenuView:(WSDropMenuView *)dropMenuView titleWithIndexPath:(WSIndexPath *)indexPath //dataSource


- (void)dropMenuView:(WSDropMenuView *)dropMenuView didSelectWithIndexPath:(WSIndexPath *)indexPath //delegate

```

测试环境：Xcode 6.2，iOS 6.0 以上