iOS DropDown下拉按钮效果代码分享

#import <UIKit/UIKit.h>
@interface RootViewController : UIViewController
@end

#import "RootViewController.h"
#import "NIDropDown.h"

@interface RootViewController ()

@end

@implementation RootViewController

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
  self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
  if (self) {
    // Custom initialization
  }
  return self;
}

- (void)viewDidLoad
{
  [super viewDidLoad];
  // Do any additional setup after loading the view.
  
  self.title=@"DropDown";
  
  UIButton *button=[UIButton buttonWithType:UIButtonTypeRoundedRect];
  button.frame=CGRectMake(10, 100, 150,30);
  button.backgroundColor=[UIColor redColor];
  [button addTarget:self action:@selector(doClickAction:) forControlEvents:UIControlEventTouchUpInside];
  [self.view addSubview:button];
  
  
  
 
}
-(void)doClickAction:(UIButton *)btn
{
   NSArray *dataArray=[NSArray arrayWithObjects:@"1",@"2",@"3",@"4",@"5", nil];
  
  NIDropDown *dropDown=[[NIDropDown alloc]init];
  [dropDown showDropDown:btn andHeight:[dataArray count]*36 andData:dataArray];
  [self.view addSubview:dropDown];
}
- (void)didReceiveMemoryWarning
{
  [super didReceiveMemoryWarning];
  // Dispose of any resources that can be recreated.
}