/** 设置导航栏左侧内容 */

- (void)setupLeftNavItem {

    // Logo

    UIImageView *logoView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"icon_meituan_logo"]];

    UIBarButtonItem *logoItem = [[UIBarButtonItem alloc] initWithCustomView:logoView];

    // 类别

    DJNavItem *categoryView = [DJNavItem item];

    [categoryView addTarget:self action:@selector(onCategoryNavItemDidClick)];

    UIBarButtonItem *categoryItem = [[UIBarButtonItem alloc] initWithCustomView:categoryView];

    self.categoryItem = categoryItem;

    // 地区

    DJNavItem *areaView = [DJNavItem item];

    [areaView addTarget:self action:@selector(onAreaNavItemDidClick)];

    UIBarButtonItem *areaItem = [[UIBarButtonItem alloc] initWithCustomView:areaView];

    self.areaItem = areaItem;

    // 排序

    DJNavItem *sortView = [DJNavItem item];

    [sortView addTarget:self action:@selector(onSortNavItemDidClick)];

    UIBarButtonItem *sortItem = [[UIBarButtonItem alloc] initWithCustomView:sortView];

    self.sortItem = sortItem;

    self.navigationItem.leftBarButtonItems = @[logoItem,categoryItem,areaItem,sortItem];

}

#pragma mark - 导航按钮被点击

- (void)onCategoryNavItemDidClick {

    // 创建将要显示的Controller

    DJCategoryViewController *categoryVC = [[DJCategoryViewController alloc] init];

    // 设置控制器View的显示大小

    categoryVC.preferredContentSize = CGSizeMake(, );

    // 设置Modal类型

    categoryVC.modalPresentationStyle = UIModalPresentationPopover;

    // 获取Popover

    UIPopoverPresentationController *categoryPopover = categoryVC.popoverPresentationController;

    // 相对于哪个View来显示

    categoryPopover.sourceView = self.categoryItem.customView;

    // 显示位置

    categoryPopover.sourceRect = self.categoryItem.customView.bounds;

    // 设置popover箭头的显示方向

    categoryPopover.permittedArrowDirections = UIPopoverArrowDirectionAny;

    // 跳转

    [self presentViewController:categoryVC animated:YES completion:nil];

}

#import "DJNavDropView.h"

#import "DJCategory.h"

@interface DJNavDropView()<UITableViewDataSource,UITableViewDelegate>

@property (weak, nonatomic) IBOutlet UITableView *mainTableView;

@end

@implementation DJNavDropView

+ (instancetype)dropView {

   return[[[NSBundle mainBundle] loadNibNamed:@"DJNavDropView" owner:nil options:nil] lastObject];

}

- (void)setCategoryList:(NSArray *)categoryList {

    _categoryList = categoryList;

    // 刷新数据

    [self.mainTableView reloadData];

}

#pragma mark - TableView 数据源方法

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {

    return self.categoryList.count;

}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

    static NSString *ID = @"category";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:ID];

    if (!cell) {

        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:ID];

    }

    DJCategory *categoryItem = self.categoryList[indexPath.row];

    cell.textLabel.text = categoryItem.name;

    cell.imageView.image = [UIImage imageNamed:categoryItem.icon];

    return cell;

}

@end