Xcode/iOS：如何在向下滚动时隐藏导航和工具栏？
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Xcode/iOS: How to hide Navigation- AND ToolBar on scroll down?
提问by filou
I would like to hide both bars on scroll down on my iPhone. When I scroll up, they should appear again.. How can I handle this?
我想在 iPhone 上向下滚动时隐藏两个栏。当我向上滚动时，它们应该会再次出现.. 我该如何处理？
采纳答案by vikingosegundo
The accepted answer does not work for me, as scrollViewWillBeginScroll:is not a delegate method.
接受的答案对我不起作用，因为scrollViewWillBeginScroll:它不是委托方法。
Instead I do
相反，我做
-(void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
{
[[NSNotificationCenter defaultCenter] postNotificationName:@"BarsShouldHide" object:self];
}
-(void)scrollViewDidEndDragging:(UIScrollView *)scrollView
willDecelerate:(BOOL)decelerate
{
if(!decelerate)
[[NSNotificationCenter defaultCenter] postNotificationName:@"BarsShouldUnhide"
object:self];
}
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
[[NSNotificationCenter defaultCenter] postNotificationName:@"BarsShouldUnhide"
object:self];
}
Anywhere in the app objects can listen for this notification,like
应用程序对象中的任何地方都可以侦听此通知，例如
- (void)viewDidLoad
{
[super viewDidLoad];
[[NSNotificationCenter defaultCenter] addObserverForName:@"BarsShouldHide"
object:nil
queue:nil
usingBlock:^(NSNotification *note) {
//hide tab bar with animation;
}];
[[NSNotificationCenter defaultCenter] addObserverForName:@"BarsShouldUnhide"
object:nil
queue:nil
usingBlock:^(NSNotification *note) {
//Unhide tab bar with animation;
}];
}
This code will hide the bars for any scroll. if you want to have only on down, the same locationOffsettrick as in the accepted answer should work.
此代码将隐藏任何滚动条。如果你只想放下，与locationOffset接受的答案相同的技巧应该有效。
回答by mdominick
- (void)scrollViewWillBeginScroll :(UIScrollView *)scrollView {
if (scrollView.contentOffset.y < lastOffset.y) {
[toolBar setHidden:YES];
[[[self navigationController] navigationBar] setHidden:YES];
} else{
// unhide
}
}
- (void)scrollViewDidScroll :(UIScrollView *)scrollView {
/// blah blah
lastOffset = scrollView.contentOffset;
}
Note: lastOffsetis an CGPointand it goes in your header file: @Interface.
注意：lastOffset是一个CGPoint，它在你的头文件中：@Interface。
回答by Grant Park
Here's my solution in Swift; it works beautifully
这是我在 Swift 中的解决方案；它工作得很好
func scrollViewDidScroll(scrollView: UIScrollView) {
let navController: UINavigationController = self.navigationController!
if self.collectionView.panGestureRecognizer.translationInView(self.view).y <= 0.0 {
defaultCenter.postNotificationName("stuffShouldHide", object: self)
} else {
defaultCenter.postNotificationName("stuffShouldUnhide", object: self)
}
}
回答by anoop4real
You might check this, available from iOS8, i think this is the reverse of what you are looking for...but worth checking as it is something standard and this is how Safari works.
您可能会检查这个，可从 iOS8 获得，我认为这与您正在寻找的相反......但值得检查，因为它是标准的东西，这就是 Safari 的工作方式。
Swift
var hidesBarsOnSwipe: Bool
Objective-C
@property(nonatomic, readwrite, assign) BOOL hidesBarsOnSwipe Discussion
When this property is set to YES, an upward swipe hides the navigation bar and toolbar. A downward swipe shows both bars again. If the toolbar does not have any items, it remains visible even after a swipe. The default value of this property is NO.
迅速
var hidesBarsOnSwipe: Bool
目标-C
@property(nonatomic, readwrite,assign) BOOL hidesBarsOnSwipe 讨论
当此属性设置为 YES 时，向上滑动会隐藏导航栏和工具栏。向下滑动再次显示两个条形。如果工具栏没有任何项目，即使在滑动后它仍然可见。此属性的默认值为 NO。
