在导航栏中显示搜索栏而不在 iOS 11 上滚动

Question

I'm attaching a UISearchController to the navigationItem.searchController property of a UITableViewController on iOS 11. This works fine: I can use the nice iOS 11-style search bar.

However, I'd like to make the search bar visible on launch. By default, the user has to scroll up in the table view to see the search bar. Does anyone know how is this is possible?

Left: default situation after launch. Right: search bar made visible (by scrolling up). I'd like to have the search bar visible after launch, as in the right screenshot.

I already found that the search bar can be made visible by setting the property hidesSearchBarWhenScrolling of my navigation item to false. However, this causes the search bar to always be visible — even when scrolling down —, which is not what I want.

Answer 1

The following makes the search bar visible at first, then allows it to hide when scrolling:

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)
    if #available(iOS 11.0, *) {
        navigationItem.hidesSearchBarWhenScrolling = false
    }
}

override func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)
    if #available(iOS 11.0, *) {
        navigationItem.hidesSearchBarWhenScrolling = true
    }
}

Using isActive didn't do what I wanted, it makes the search bar active (showing cancel button, etc.), when all I want is for it to be visible.

Answer 2

You can set the property isActive to true after adding the searchController to the navigationItem .

Just like this:

override func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)
    searchController.isActive = true
}

Answer 3

For me it worked after adding following lines in viewDidLoad() method:

navigationController?.navigationBar.prefersLargeTitles = true
navigationController!.navigationBar.sizeToFit()

Answer 4

On iOS 13, @Jordan Wood's answer didn't work. Instead I did:

override func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)
    UIView.performWithoutAnimation {
        searchController.isActive = true
        searchController.isActive = false
    }
}

Answer 5

The following make searchBar to become first responder:

   override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)

        DispatchQueue.main.async {
            self.searchController.searchBar.becomeFirstResponder()
        }
    }

Answer 6

For (iOS 13.0, *) and SwiftUI

navigationController?.navigationBar.sizeToFit()

Example:

struct SearchBarModifier: ViewModifier {
        let searchBar: SearchBar
        func body(content: Content) -> some View {
        content
            .overlay(
                ViewControllerResolver { viewController in
                    viewController.navigationItem.searchController = self.searchBar.searchController
                    viewController.navigationController?.navigationBar.sizeToFit()

                }
                .frame(width: 0, height: 0)
            )
    }
}