问题
I am trying to mimic the UINavigationController's new hidesBarsOnTap with a tab bar. I have seen many answers to this that either point to setting the hidesBottomBarWhenPushed on a viewController which only hides it entirely and not when tapped.
@IBAction func tapped(sender: AnyObject) {
// what goes here to show/hide the tabBar ???
}
thanks in advance
EDIT: as per the suggestion below I tried
self.tabBarController?.tabBar.hidden = true
which does indeed hide the tabBar (toggles true/false on tap), but without animation. I will ask that as a separate question though.
回答1:
After much hunting and trying out various methods to gracefully hide/show the UITabBar using Swift I was able to take this great solution by danh and convert it to Swift:
func setTabBarVisible(visible: Bool, animated: Bool) {
//* This cannot be called before viewDidLayoutSubviews(), because the frame is not set before this time
// bail if the current state matches the desired state
if (tabBarIsVisible() == visible) { return }
// get a frame calculation ready
let frame = self.tabBarController?.tabBar.frame
let height = frame?.size.height
let offsetY = (visible ? -height! : height)
// zero duration means no animation
let duration: TimeInterval = (animated ? 0.3 : 0.0)
// animate the tabBar
if frame != nil {
UIView.animate(withDuration: duration) {
self.tabBarController?.tabBar.frame = frame!.offsetBy(dx: 0, dy: offsetY!)
return
}
}
}
func tabBarIsVisible() -> Bool {
return (self.tabBarController?.tabBar.frame.origin.y)! < self.view.frame.maxY
}
// Call the function from tap gesture recognizer added to your view (or button)
@IBAction func tapped(_ sender: Any?) {
setTabBarVisible(visible: !tabBarIsVisible(), animated: true)
}
回答2:
Loved Michael Campsall's answer. Here's the same code as extension, if somebody is interested:
Swift 2.3
extension UITabBarController {
func setTabBarVisible(visible:Bool, animated:Bool) {
// bail if the current state matches the desired state
if (tabBarIsVisible() == visible) { return }
// get a frame calculation ready
let frame = self.tabBar.frame
let height = frame.size.height
let offsetY = (visible ? -height : height)
// animate the tabBar
UIView.animateWithDuration(animated ? 0.3 : 0.0) {
self.tabBar.frame = CGRectOffset(frame, 0, offsetY)
self.view.frame = CGRectMake(0, 0, self.view.frame.width, self.view.frame.height + offsetY)
self.view.setNeedsDisplay()
self.view.layoutIfNeeded()
}
}
func tabBarIsVisible() ->Bool {
return self.tabBar.frame.origin.y < CGRectGetMaxY(self.view.frame)
}
}
Swift 3
extension UIViewController {
func setTabBarVisible(visible: Bool, animated: Bool) {
//* This cannot be called before viewDidLayoutSubviews(), because the frame is not set before this time
// bail if the current state matches the desired state
if (isTabBarVisible == visible) { return }
// get a frame calculation ready
let frame = self.tabBarController?.tabBar.frame
let height = frame?.size.height
let offsetY = (visible ? -height! : height)
// zero duration means no animation
let duration: TimeInterval = (animated ? 0.3 : 0.0)
// animate the tabBar
if frame != nil {
UIView.animate(withDuration: duration) {
self.tabBarController?.tabBar.frame = frame!.offsetBy(dx: 0, dy: offsetY!)
return
}
}
}
var isTabBarVisible: Bool {
return (self.tabBarController?.tabBar.frame.origin.y ?? 0) < self.view.frame.maxY
}
}
回答3:
I had to adapt the accepted answer to this question a bit. It was hiding the bar but my view wasn't sizing itself appropriately so I was left with a space at the bottom.
The following code successfully animates the hiding of the tab bar while resizing the view to avoid that issue.
Updated for Swift 3 (now with less ugly code)
func setTabBarVisible(visible: Bool, animated: Bool) {
guard let frame = self.tabBarController?.tabBar.frame else { return }
let height = frame.size.height
let offsetY = (visible ? -height : height)
let duration: TimeInterval = (animated ? 0.3 : 0.0)
UIView.animate(withDuration: duration,
delay: 0.0,
options: UIViewAnimationOptions.curveEaseIn,
animations: { [weak self] () -> Void in
guard let weakSelf = self else { return }
weakSelf.tabBarController?.tabBar.frame = frame.offsetBy(dx: 0, dy: offsetY)
weakSelf.view.frame = CGRect(x: 0, y: 0, width: weakSelf.view.frame.width, height: weakSelf.view.frame.height + offsetY)
weakSelf.view.setNeedsDisplay()
weakSelf.view.layoutIfNeeded()
})
}
func handleTap(recognizer: UITapGestureRecognizer) {
setTabBarVisible(visible: !tabBarIsVisible(), animated: true)
}
func tabBarIsVisible() -> Bool {
guard let tabBar = tabBarController?.tabBar else { return false }
return tabBar.frame.origin.y < UIScreen.main.bounds.height
}
Older Swift 2 Version
func setTabBarVisible(visible: Bool, animated: Bool) {
// hide tab bar
let frame = self.tabBarController?.tabBar.frame
let height = frame?.size.height
var offsetY = (visible ? -height! : height)
println ("offsetY = \(offsetY)")
// zero duration means no animation
let duration:NSTimeInterval = (animated ? 0.3 : 0.0)
// animate tabBar
if frame != nil {
UIView.animateWithDuration(duration) {
self.tabBarController?.tabBar.frame = CGRectOffset(frame!, 0, offsetY!)
self.view.frame = CGRectMake(0, 0, self.view.frame.width, self.view.frame.height + offsetY!)
self.view.setNeedsDisplay()
self.view.layoutIfNeeded()
return
}
}
}
@IBAction func handleTap(recognizer: UITapGestureRecognizer) {
setTabBarVisible(!tabBarIsVisible(), animated: true)
}
func tabBarIsVisible() -> Bool {
return self.tabBarController?.tabBar.frame.origin.y < UIScreen.mainScreen().bounds.height
}
回答4:
You can just add this line to ViewDidLoad() in swift :
self.tabBarController?.tabBar.hidden = true
回答5:
I use tabBar.hidden = YES in ObjC to hide the tab bar in certain cases. I have not tried wiring it up to a tap event, though.
回答6:
Code is okay but when you use presentViewController, tabBarIsVisible() is not working. To keep UITabBarController always hidden use just this part:
extension UITabBarController {
func setTabBarVisible(visible:Bool, animated:Bool) {
let frame = self.tabBar.frame
let height = frame.size.height
let offsetY = (visible ? -height : height)
UIView.animateWithDuration(animated ? 0.3 : 0.0) {
self.tabBar.frame = CGRectOffset(frame, 0, offsetY)
self.view.frame = CGRectMake(0, 0, self.view.frame.width, self.view.frame.height + offsetY)
self.view.setNeedsDisplay()
self.view.layoutIfNeeded()
}
}
}
回答7:
Swift 3 version:
func setTabBarVisible(visible:Bool, animated:Bool) {
//* This cannot be called before viewDidLayoutSubviews(), because the frame is not set before this time
// bail if the current state matches the desired state
if (tabBarIsVisible() == visible) { return }
// get a frame calculation ready
let frame = self.tabBarController?.tabBar.frame
let height = frame?.size.height
let offsetY = (visible ? -height! : height)
// zero duration means no animation
let duration:TimeInterval = (animated ? 0.3 : 0.0)
// animate the tabBar
if frame != nil {
UIView.animate(withDuration: duration) {
self.tabBarController?.tabBar.frame = (self.tabBarController?.tabBar.frame.offsetBy(dx: 0, dy: offsetY!))!
return
}
}
}
func tabBarIsVisible() ->Bool {
return (self.tabBarController?.tabBar.frame.origin.y)! < self.view.frame.midY
}
回答8:
For Swift 4, and animating + hiding by placing tabBar outside the view:
if let tabBar = tabBarController?.tabBar,
let y = tabBar.frame.origin.y + tabBar.frame.height {
UIView.animate(withDuration: 0.2) {
tabBar.frame = CGRect(origin: CGPoint(x: tabBar.frame.origin.x, y: y), size: tabBar.frame.size)
}
}
回答9:
To make the animations work with self.tabBarController?.tabBar.hidden = true just do this:
UIView.animateWithDuration(0.2, animations: {
self.tabBarController?.tabBar.hidden = true
})
Other than the other solution this will also work nicely with autolayout.
来源：https://stackoverflow.com/questions/27008737/how-do-i-hide-show-tabbar-when-tapped-using-swift-in-ios8