问题
How to to hide the navigation bar when swiping up and to show when swiping down (like on facebook for example) in SwiftUI? In UKit there is navigationBar.hideBarsOnSwipe, but I do cannot seem to find such functionality in SwiftUI. Am I missing something, or there is indeed no hide on swipe in swiftUI?
Thanks in advance!!
回答1:
No native API in SwiftUI so far (both 1.0 & 2.0). So here is a possible working solution based on NavigationConfigurator provided in this answer
Tested with Xcode 12 / iOS 14
struct TestHideOnSwipe: View {
var body: some View {
NavigationView {
List(0..<100) { i in
Text("Item \(i)")
}
.background(NavigationConfigurator { navigationConfigurator in
navigationConfigurator.hidesBarsOnSwipe = true // << here !!
})
.navigationBarTitle(Text("Demo"), displayMode: .inline)
}
}
}
回答2:
you can get this attribute in navigation controller's attributes inspector.
func scrollViewWillEndDragging(_ scrollView: UIScrollView, withVelocity velocity: CGPoint, targetContentOffset: UnsafeMutablePointer<CGPoint>) {
if(velocity.y>0) {
//Code will work without the animation block.I am using animation block incase if you want to set any delay to it.
UIView.animate(withDuration: 2.5, delay: 0, options: UIViewAnimationOptions(), animations: {
self.navigationController?.setNavigationBarHidden(true, animated: true)
self.navigationController?.setToolbarHidden(true, animated: true)
print("Hide")
}, completion: nil)
} else {
UIView.animate(withDuration: 2.5, delay: 0, options: UIViewAnimationOptions(), animations: {
self.navigationController?.setNavigationBarHidden(false, animated: true)
self.navigationController?.setToolbarHidden(false, animated: true)
print("Unhide")
}, completion: nil)
}
}
if you want to do it programmatically. Note: If you passing any data from this VC to another VC that embedded with navigationController.You may need to unhide the NavigationBar.
来源：https://stackoverflow.com/questions/61324597/hide-navigation-bar-on-swipe-of-a-list-in-swiftui