iOS 低配导航栏下拉菜单

轮子太多,撸了个基础样式,大家自己想要什么效果可以自己继续改造一下...
效果如下:

SpingPop.gif
个人一般追求代码即注释...不多做说明

#import <UIKit/UIKit.h>

@class TYNavigationDropdownMenuView;
@protocol TYNavigationDropdownMenuViewDelegate <NSObject>

@optional
- (void)ty_navigationDropdownMenuView:(TYNavigationDropdownMenuView *)view didSelectText:(NSString *)text;

@end

@interface TYNavigationDropdownMenuView : UIView

// 内容数组
@property (nonatomic, strong) NSArray<NSString *> *menuContextArray;
// 选项高度
@property (nonatomic, assign) CGFloat rowHeight;
// 是否已经显示
@property (nonatomic, assign) BOOL isShow;
@property (nonatomic, weak) id<TYNavigationDropdownMenuViewDelegate> delegate;

- (void)showInView:(UIView *)view;
- (void)dismiss;

@end

#import "TYNavigationDropdownMenuView.h"

@interface TYNavigationDropdownMenuView () <UITableViewDelegate,UITableViewDataSource>

@property (nonatomic, strong) UIView *backgroundView;
@property (nonatomic, strong) UITableView *containerTableView;

@end

@implementation TYNavigationDropdownMenuView

- (instancetype)initWithFrame:(CGRect)frame {
    self = [super initWithFrame:frame];
    if (self) {
        self.menuContextArray = [NSArray array];
        self.rowHeight = 30;
        [self setupBaseView];
    }
    return self;
}

- (void)setupBaseView {

    self.backgroundView = ({
        UIView *backgroundView = [[UIView alloc] initWithFrame:self.bounds];
        backgroundView.backgroundColor = [UIColor blackColor];
        backgroundView.alpha = 0.f;
        
        UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(backgroundViewDidTapped:)];
        [backgroundView addGestureRecognizer:tap];
        
        [self addSubview:backgroundView];
        backgroundView;
    });
    
    self.containerTableView = ({
        UITableView *tableView = [[UITableView alloc] initWithFrame:CGRectMake(0, 0, [UIScreen mainScreen].bounds.size.width, 0) style:UITableViewStylePlain];
        tableView.delegate = self;
        tableView.dataSource = self;
        tableView.rowHeight = _rowHeight;
        tableView.showsVerticalScrollIndicator = NO;
        tableView.scrollEnabled = NO;
        [self addSubview:tableView];
        tableView;
    });
}


#pragma mark - Public Methods
- (void)showInView:(UIView *)view {
    [view addSubview:self];
    self.isShow = YES;
    
    CGFloat height = _menuContextArray.count * _rowHeight;
    // 默认,导航栏要是非透明的,这样 tableview 才可以藏到导航栏下面不被发现,这个时候 当前 view 的坐标(0,0)是从导航栏下面开始,而不是状态栏
    self.containerTableView.frame = CGRectMake(0, -height, [UIScreen mainScreen].bounds.size.width, height);
    [self.containerTableView reloadData];
    dispatch_async(dispatch_get_main_queue(), ^{
        // 结束所有当前响应..比如弹出的键盘..
        [view endEditing:YES];
        CGFloat y = 0;
        CGRect endFrame = self.containerTableView.frame;
        endFrame.origin.y = y;
        
        [UIView animateWithDuration:0.6
                              delay:0
             usingSpringWithDamping:0.8
              initialSpringVelocity:2
                            options:UIViewAnimationOptionCurveEaseInOut
                         animations:^{
                             self.backgroundView.alpha = 0.2f;
                             self.containerTableView.frame = endFrame;
                         } completion:nil];
    });
}

- (void)dismiss {
    self.isShow = NO;
    dispatch_async(dispatch_get_main_queue(), ^{
        CGFloat y = - self.containerTableView.frame.size.height;
        CGRect endFrame = self.containerTableView.frame;
        endFrame.origin.y = y;
        
        [UIView animateWithDuration:0.3
                              delay:0
                            options:UIViewAnimationOptionCurveEaseInOut
                         animations:^{
                             self.backgroundView.alpha = 0.f;
                             self.containerTableView.frame = endFrame;
                         } completion:^(BOOL finished) {
                             [self removeFromSuperview];
                         }];
    });
}


#pragma mark - UITableViewDataSource Methods
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return _menuContextArray.count;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    static NSString *cellIdent = @"Cell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdent];
    if (!cell) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdent];
    }
    cell.textLabel.text = _menuContextArray[indexPath.row];
    return cell;
}


#pragma mark - UITableViewDelegate Methods
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
    return _rowHeight;
}

- (void)tableView:(nonnull UITableView *)tableView didSelectRowAtIndexPath:(nonnull NSIndexPath *)indexPath {
    [tableView deselectRowAtIndexPath:indexPath animated:YES];
    if ([_delegate respondsToSelector:@selector(ty_navigationDropdownMenuView:didSelectText:)]) {
        [_delegate ty_navigationDropdownMenuView:self didSelectText:_menuContextArray[indexPath.row]];
    }
    [self dismiss];
}


#pragma mark - Action Events
- (void)backgroundViewDidTapped:(UITapGestureRecognizer *)gesture{
    [self dismiss];
}

- (void)dealloc {
    NSLog(@"%@-释放了",self.class);
}

@end

收工.....