如何从 navigationItem 添加和删除 searchBar答案

【问题标题】：How to add and remove searchBar from navigationItem如何从 navigationItem 添加和删除 searchBar
【发布时间】：2019-04-07 08:24:15
【问题描述】：

我在向 UINavigationBar 添加和删除 UISearchControllers searchBar 时遇到问题。

这是我正在做的事情：

将 searchBar 添加到视图中

searchController = [[UISearchController alloc]initWithSearchResultsController:nil];

searchController.searchResultsUpdater = self;
searchController.searchBar.delegate = self;

searchController.dimsBackgroundDuringPresentation = NO;
searchController.hidesNavigationBarDuringPresentation = NO;
searchController.searchBar.searchBarStyle = UISearchBarStyleProminent;
searchController.searchBar.barTintColor = [UIColor blackColor];
searchController.searchBar.tintColor = [UIColor darkGrayColor];

[searchController.searchBar setFrame:CGRectMake(0, 200, 320, searchController.searchBar.frame.size.height)];
[self.view addSubview:searchController.searchBar];

点击按钮将 searchBar 添加到 navigationItem 这按预期工作

[self.navigationController setNavigationBarHidden:false];
self.navigationItem.titleView = searchController.searchBar;
self.navigationItem.hidesBackButton = true;

这是我得到奇怪行为的地方：

在另一个按钮上单击从导航栏中删除 searchBar 并将其添加回视图

[searchController.searchBar removeFromSuperview];
[self.navigationController setNavigationBarHidden:YES animated:true];
[self.view addSubview:searchController.searchBar];

[searchController.searchBar setFrame:CGRectMake(0, 200, 320, searchController.searchBar.frame.size.height)];

searchBar 已按预期从导航栏中移除，但并未返回到主视图。（好吧，我在任何地方都看不到）

我记录了搜索栏的值，我可以看到它有我给它的框架。

我们将不胜感激任何帮助，

谢谢

【问题讨论】：

标签： ios objective-c uinavigationcontroller

【解决方案1】：

您应该首先将navigationItem .titleView 设置为nil，然后在主线程中设置setFrame:。

- (IBAction)addBar:(id)sender {
    self.navigationItem.titleView = nil;
    [searchController.searchBar removeFromSuperview];
    [self.navigationController setNavigationBarHidden:NO animated:YES];
    self.navigationItem.titleView = searchController.searchBar;
    self.navigationItem.hidesBackButton = YES;
}

- (IBAction)removeBar:(id)sender {
    self.navigationItem.titleView = nil;
    [searchController.searchBar removeFromSuperview];
    [self.view addSubview:searchController.searchBar];
    [self.navigationController setNavigationBarHidden:YES animated:YES];
    dispatch_async(dispatch_get_main_queue(), ^{
        [self->searchController.searchBar setFrame:CGRectMake(0, 200, 320, self->searchController.searchBar.frame.size.height)];
    });
}

顺便说一句，我认为在添加到navigationItem.titleView 时，最好将搜索栏放在包装器UIView 中。

【讨论】：