显示/隐藏SearchBar后，后退按钮图像不显示

Question

我的NavigationBar中有一个SearchBar。单击SearchBar时，我将其显示在导航栏上的“后退”按钮上。但是，当我重新显示“后退”按钮时，它旁边的箭头不再可见。这就是我的意思：

这是我的代码：

#import "SearchViewController.h"

@interface SearchViewController ()

@end

- (void)viewDidLoad {
    [super viewDidLoad];
    if ([self respondsToSelector:@selector(edgesForExtendedLayout)])
        self.edgesForExtendedLayout = UIRectEdgeNone;

    UISearchBar *searchBar = [UISearchBar new];
    searchBar.showsCancelButton = NO;
    [searchBar sizeToFit];
    searchBar.delegate = self;

    self.navigationItem.titleView = searchBar;
    self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:nil style:UIBarButtonItemStylePlain target:self action:nil];

}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
}

- (void)searchBarTextDidBeginEditing:(UISearchBar *)searchBar
{
[searchBar setShowsCancelButton:YES animated:YES];
    self.navigationItem.hidesBackButton = YES;
    self.navigationItem.titleView = searchBar;
    self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:nil style:UIBarButtonItemStylePlain target:self action:nil];
}

- (void)searchBarTextDidEndEditing:(UISearchBar *)searchBar
{
    [searchBar setShowsCancelButton:NO animated:YES];
}

- (void)searchBarCancelButtonClicked:(UISearchBar *)searchBar
{
    [searchBar resignFirstResponder];
    [searchBar setShowsCancelButton:NO animated:YES];

    self.navigationItem.titleView = searchBar;
    self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:nil style:UIBarButtonItemStylePlain target:self action:nil];
    self.navigationItem.hidesBackButton = NO;
}

@end

关于为什么会发生这种情况的任何想法？谢谢！

Answer 1

只需将此行添加到方法searchBarCancelButtonClicked:searchBar:

即可

self.navigationItem.leftBarButtonItem = nil;

Answer 2

*- (void)viewDidLoad {
    [super viewDidLoad];
    if ([self respondsToSelector:@selector(edgesForExtendedLayout)])
        self.edgesForExtendedLayout = UIRectEdgeNone;
    UISearchBar *searchBar = [UISearchBar new];
    searchBar.showsCancelButton = NO;
    [searchBar sizeToFit];
    searchBar.delegate = self;
    self.navigationItem.leftBarButtonItem = nil;
    self.navigationItem.titleView = searchBar;
    self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:nil style:UIBarButtonItemStylePlain target:self action:nil];
}
- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
}
- (void)searchBarTextDidBeginEditing:(UISearchBar *)searchBar
{
[searchBar setShowsCancelButton:YES animated:YES];
    self.navigationItem.hidesBackButton = YES;
    self.navigationItem.titleView = searchBar;
    self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:nil style:UIBarButtonItemStylePlain target:self action:nil];
}
- (void)searchBarTextDidEndEditing:(UISearchBar *)searchBar
{
    [searchBar setShowsCancelButton:NO animated:YES];
}
- (void)searchBarCancelButtonClicked:(UISearchBar *)searchBar
{
    [searchBar resignFirstResponder];
    [searchBar setShowsCancelButton:NO animated:YES];
    self.navigationItem.titleView = searchBar;
    self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:nil style:UIBarButtonItemStylePlain target:self action:nil];
    self.navigationItem.hidesBackButton = NO;
}*