本文實例為大家分享了簡單封裝的iOS下拉選擇菜單代碼，供大家參考，具體內容如下

// 
// OrderListDownMenu.h 
 
#import <UIKit/UIKit.h> 
 
@protocol OrderListDownMenuDelegate <NSObject> 
 
- (void)OrderListDownMenu:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath; 
 
@end 
 
typedef void(^Dismiss)(void); 
 
@interface OrderListDownMenu : UIView<UITableViewDataSource, UITableViewDelegate> 
 
@property (nonatomic, strong) UITableView *tableView; 
@property (nonatomic, assign) id<OrderListDownMenuDelegate> delegate; 
@property (nonatomic, strong) NSArray *arrData; 
@property (nonatomic, strong) NSArray *arrImgName; 
@property (nonatomic, copy) Dismiss dismiss; 
 
- (instancetype)initWithDataArr:(NSArray *)dataArr origin:(CGPoint)origin width:(CGFloat)width rowHeight:(CGFloat)rowHeight; 
 
- (void)dismissWithCompletion:(void (^)(OrderListDownMenu *object))completion; 
 
@end 

#import "OrderListDownMenu.h" 
 
#define TopToView 63.0f 
#define rightToView kScreenWidth - 15.0f 
#define LeftToView kScreenWidth - 145.0 - 10.0f 
#define CellLineEdgeInsets UIEdgeInsetsMake(0, -80, 0, 0) 
#define kScreenWidth    [UIScreen mainScreen].bounds.size.width 
#define kScreenHeight    [UIScreen mainScreen].bounds.size.height 
 
@interface OrderListDownMenu() 
 
@property (nonatomic, assign) CGPoint origin; 
@property (nonatomic, assign) CGFloat rowHeight; 
 
@end 
 
@implementation OrderListDownMenu 
 
- (instancetype)initWithDataArr:(NSArray *)dataArr origin:(CGPoint)origin width:(CGFloat)width rowHeight:(CGFloat)rowHeight { 
   
  self = [super initWithFrame:CGRectMake(0, 0, kScreenWidth, kScreenHeight)]; 
  if (self) { 
    if (rowHeight <= 0) { 
      rowHeight = 50; 
    } 
     
    // 設置背景顏色 
    self.backgroundColor = [UIColor colorWithRed:0 green:0 blue:0 alpha:0.2]; 
    self.origin = origin; 
    self.rowHeight = rowHeight; 
    self.arrData = [dataArr copy]; 
    self.tableView = [[UITableView alloc] initWithFrame:CGRectMake(origin.x + LeftToView, origin.y + TopToView, width, rowHeight * dataArr.count) style:UITableViewStylePlain]; 
    _tableView.dataSource = self; 
    _tableView.delegate = self; 
    [self addSubview:_tableView]; 
     
    _tableView.backgroundColor = [UIColor whiteColor]; 
    _tableView.layer.cornerRadius = 2; 
    _tableView.bounces = NO; 
    _tableView.layer.cornerRadius = 8; 
    _tableView.separatorColor = [UIColor colorWithWhite:0.3 alpha:1]; 
    
    _tableView.separatorStyle = UITableViewCellSelectionStyleNone; 
    [_tableView registerClass:[UITableViewCell class] forCellReuseIdentifier:@"cell"]; 
     
    if ([self.tableView respondsToSelector:@selector(setSeparatorInset:)]) { 
      [self.tableView setSeparatorInset:CellLineEdgeInsets]; 
    } 
     
    if ([self.tableView respondsToSelector:@selector(setLayoutMargins:)]) { 
      [self.tableView setLayoutMargins:CellLineEdgeInsets]; 
    } 
  } 
  return self; 
} 
 
- (void)layoutSubviews { 
  [super layoutSubviews]; 
} 
 
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { 
  return self.arrData.count; 
} 
 
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath { 
  return self.rowHeight; 
} 
 
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { 
   
  UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"cell"]; 
  cell.textLabel.textColor = THEME_COLOR_GRAY_1; 
  cell.textLabel.font = [UIFont systemFontOfSize:15]; 
  cell.textLabel.text = self.arrData[indexPath.row]; 
   
  if (self.arrImgName.count > indexPath.row) { 
    cell.imageView.image = [UIImage imageNamed:self.arrImgName[indexPath.row]]; 
    cell.imageView.contentMode = UIViewContentModeScaleAspectFit; 
  } 
   
  UILabel *label = [[UILabel alloc] init]; 
  label.frame = CGRectMake(0, 49, _tableView.frame.size.width, 0.5); 
  label.backgroundColor = THEME_SEPARATOR_COLOR; 
  [cell.contentView addSubview:label]; 
   
  return cell; 
} 
 
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { 
   
  if([self.delegate respondsToSelector:@selector(OrderListDownMenu:didSelectRowAtIndexPath:)]){ 
    [self.delegate OrderListDownMenu:tableView didSelectRowAtIndexPath:indexPath]; 
  } 
   
  [tableView deselectRowAtIndexPath:indexPath animated:YES]; 
  [self dismissWithCompletion:nil]; 
} 
 
- (void)dismissWithCompletion:(void (^)(OrderListDownMenu *object))completion { 
   
  __weak __typeof(self) weakSelf = self; 
  [UIView animateWithDuration:0.2 animations:^{ 
    weakSelf.alpha = 0; 
    weakSelf.tableView.frame = CGRectMake(weakSelf.origin.x + LeftToView + 145, weakSelf.origin.y + TopToView, 0, 0); 
  } completion:^(BOOL finished) { 
    [weakSelf removeFromSuperview]; 
    if (completion) { 
      completion(weakSelf); 
    } 
    if (weakSelf.dismiss) { 
      weakSelf.dismiss(); 
    } 
  }]; 
} 
 
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event { 
   
  UITouch *touch = [touches anyObject]; 
  if (![touch.view isEqual:self.tableView]) { 
    [self dismissWithCompletion:nil]; 
  } 
} 
 
- (void)drawRect:(CGRect)rect { 
   
  //[colors[serie] setFill]; 
   
  //拿到當前視圖准備好的畫板 
   
  CGContextRef context = UIGraphicsGetCurrentContext(); 
   
  //利用path進行繪制三角形 
   
  CGContextBeginPath(context);//標記 
   
  CGContextMoveToPoint(context, 
             rightToView - 13, 53);//設置起點 
   
  CGContextAddLineToPoint(context, 
              rightToView - 21, TopToView); 
   
  CGContextAddLineToPoint(context, 
              rightToView - 4, TopToView); 
   
  CGContextClosePath(context);//路徑結束標志，不寫默認封閉 
   
 
  [self.tableView.backgroundColor setFill]; //設置填充色 
   
  [self.tableView.backgroundColor setStroke]; //設置邊框顏色 
   
  CGContextDrawPath(context, 
           kCGPathFillStroke);//繪制路徑path 
} 
 
@end 

以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持本站。