To add segment control in UINavigationBar in Swift 5

在 Swift 5 中的 UINavigationBar 中添加段控件

    let segment: UISegmentedControl = UISegmentedControl(items: ["First", "Second"])
    segment.sizeToFit()
    if #available(iOS 13.0, *) {
        segment.selectedSegmentTintColor = UIColor.red
    } else {
       segment.tintColor = UIColor.red
    }
    segment.selectedSegmentIndex = 0
    segment.setTitleTextAttributes([NSAttributedString.Key.font : UIFont(name: "ProximaNova-Light", size: 15)!], for: .normal)
    self.navigationItem.titleView = segment

To put it in the navigationBar has a right left and title view for such things... accessed using....

把它放在导航栏中有一个左右和标题视图这样的东西......访问使用......

self.navigationItem.titleView = mySegmentedControl

self.navigationItem.titleView = mySegmentedControl

for future reference....

备查....

self.navigationItem.rightBarButtonItem
self.navigationItem.leftBarButtonItems // for adding an Array of items

To add it below the navigation view but have it static.. add it to the viewController.view... Are you using a UITableViewController? If so maybe switch to a UIViewController and add a tableView then your toolbarview as subviews to that self.view.

要将其添加到导航视图下方但使其静态...将其添加到 viewController.view... 您是否使用 UITableViewController？如果是这样，可能切换到 UIViewController 并添加一个 tableView，然后您的工具栏视图作为该 self.view 的子视图。

I think you are looking for this.

我想你正在寻找这个。

let searchVC = self.storyboard?.instantiateViewController(withIdentifier:"idofcontroller")
let searchController = UISearchController(searchResultsController: searchVC)
searchController.searchResultsUpdater = self
searchController.obscuresBackgroundDuringPresentation = false
searchController.searchBar.placeholder = "Search"
navigationItem.searchController = searchController
definesPresentationContext = true

searchController.searchBar.scopeButtonTitles = ["News", "Photos", "Videos"]
searchController.searchBar.delegate = self

This is how I do it in Objective C (sorry, I haven't learned Swift yet):

这就是我在 Objective C 中的做法（抱歉，我还没有学过 Swift）：

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.viewControllers = [self segmentViewControllers];

    self.segmentedControl = [[UISegmentedControl alloc] initWithItems: [self.segmentedControl addTarget: self
                          action: @selector(segmentClicked:)
                forControlEvents: UIControlEventValueChanged];

    CGFloat topOffset = self.navigationController.navigationBar.frame.size.height + [UIApplication sharedApplication].statusBarFrame.size.height;

    self.toolbar = [[UIToolbar alloc] initWithFrame: CGRectMake(0, topOffset, self.navigationController.navigationBar.frame.size.width, kDefaultViewHeight)];
    self.toolbar.delegate = self;

    self.navigationController.navigationBar.backgroundColor = [UIColor whiteColor];
    self.toolbar.backgroundColor = [UIColor whiteColor];
    self.toolbar.clipsToBounds = YES;

    UIBarButtonItem *segmentedControlItem = [[UIBarButtonItem alloc] initWithCustomView: self.segmentedControl];
    UIBarButtonItem *flexibleItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem: UIBarButtonSystemItemFlexibleSpace
                                                                              target: nil
                                                                              action: nil];

    [self.toolbar setItems: @[flexibleItem, segmentedControlItem, flexibleItem] animated: YES];

    [self.navigationController.view addSubview: self.toolbar];

    self.segmentedControl.selectedSegmentIndex = 0;
}

And in UITableViewController (one of the segmentViewControllers):

在 UITableViewController（segmentViewControllers 之一）中：

  self.tableView.contentInset = UIEdgeInsetsMake(topOffset, 0, 0, 0);

    CGRect currentFrame = self.tableView.frame;
    [self.tableView setFrame: CGRectMake(currentFrame.origin.x,
                                     currentFrame.origin.y,
                                     currentFrame.size.width,
                                     currentFrame.size.height + [UIApplication sharedApplication].statusBarFrame.size.height)];

you can custom navigationItem's titleView, like this:

您可以自定义导航项的 titleView，如下所示：

self.navigationItem.titleView = segmentview

you should not add subview to the navigationbar, for after push or pop UIViewcontroller ,the subview is still exsit on the navigationbar.

你不应该向导航栏添加子视图，因为在推送或弹出 UIViewcontroller 之后，子视图仍然存在于导航栏上。

You can also add the segment control to a search bar, not the navigation item. If you're like me, I needed a large title + search bar + navigation item, which would be impossible with the current top answer.

您还可以将段控件添加到搜索栏，而不是导航项。如果您像我一样，我需要一个大标题 + 搜索栏 + 导航项，这对于当前的最佳答案是不可能的。

@Abhishek 's answer is close. You would do something like the following:

@Abhishek 的答案很接近。您将执行以下操作：

// Create the search controller
let searchController = UISearchController(searchResultsController: nil)
searchController.searchResultsUpdater = self
searchController.obscuresBackgroundDuringPresentation = false
searchController.searchBar.scopeButtonTitles = ["Option 1", "Option 2"]

// Make sure the scope bar is always showing, even when not actively searching
searchController.searchBar.showsScopeBar = true

// Make sure the search bar is showing, even when scrolling
navigationItem.hidesSearchBarWhenScrolling = false

// Add the search controller to the nav item   
navigationItem.searchController = searchController
definesPresentationContext = true

@Gurjit Singh, the line with .showsScopeBar = trueis the solution to your problem.

@Gurjit Singh，.showsScopeBar = true您的问题是解决方案。