xcode 滚动uiwebview时隐藏和显示导航栏
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hide and show navbar when scroll uiwebview
提问by user2966615
i need help, i am trying to build a app in which i have a viewcontrollerwith a uiwebviewand a navbarwith 2 buttons on it. what i want to do is that when user scroll uiwebviewnavbar automatically hides like slid up sort of. but is not working they way i want it to work. let me post code here.
In viewdidloadi put this.
我需要帮助，我正在尝试构建一个应用程序，其中有一个viewcontroller带 auiwebview和一个navbar带 2 个按钮的应用程序。我想要做的是当用户滚动uiwebview导航栏时会自动隐藏起来，就像向上滑动一样。但没有按照我希望的方式工作。让我在这里发布代码。在viewdidload我把这个。
[webPage.scrollView setDelegate:self];
and then i have this method
然后我有这个方法
- (void) scrollViewDidScroll:(UIScrollView *)scrollView {
if(scrollView.contentOffset.y == 0) {
//show
NSLog(@"Show");
[self.navigationController setNavigationBarHidden:NO animated:YES];
} else {
NSLog(@"Hide");
[self.navigationController setNavigationBarHidden:YES animated:YES];
//hide
}
}
it NSLogcorrectly but nothing else navbarstill stays. :(
它NSLog正确但没有其他东西navbar仍然存在。:(
采纳答案by iOS Dev
You can try this:
你可以试试这个：
1.Declare the navigation bar, a constant with your navigation bar height and 2 BOOL variables:
1.声明导航栏，一个带有导航栏高度的常量和 2 个 BOOL 变量：
UINavigationBar *navBar;
static const CGFloat kNavBarHeight = 60.0f;
BOOL webViewScrollIsDragging;
BOOL webViewScrollIsDecelerating;
2.In viewDidLoad write the following:
2.在 viewDidLoad 中写入以下内容：
[webView.scrollView setContentInset:UIEdgeInsetsMake(kNavBarHeight, 0, 0, 0)];
[webView.scrollView setScrollIndicatorInsets:UIEdgeInsetsMake(kNavBarHeight, 0, 0, 0)];
[webView.scrollView setContentOffset:CGPointMake(0, -kNavBarHeight) animated:NO];
webView.scrollView.delegate = self;
then initialize and add your UINavigationBaras a subview to self.viewat origin (Also make sure that your UIWebViewhas the same origin, i.e (0,0)).
然后初始化并将您的UINavigationBar作为子视图添加到self.view原点（还要确保您UIWebView的原点相同，即（0,0））。
3.Implement UIScrollViewDelegatemethods (Don't forget to add UIScrollViewDelegateprotocol):
3.实现UIScrollViewDelegate方法（不要忘记添加UIScrollViewDelegate协议）：
#pragma mark - UIScrollViewDelegate Methods
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
if (scrollView == webview.scrollView)
{
if (scrollView.contentOffset.y == 1 && !webViewScrollIsDragging && !webViewScrollIsDecelerating)
{
[UIView animateWithDuration:0.3
delay:0.0
options: UIViewAnimationCurveEaseOut
animations:^(void) {
CGRect navBarFrame = CGRectMake(0,-scrollView.contentOffset.y-kNavBarHeight, self.view.bounds.size.width, kNavBarHeight);
navBar.frame = navBarFrame;
}
completion:nil];
}
else
{
CGRect navBarFrame = CGRectMake(0,-scrollView.contentOffset.y-kNavBarHeight, self.view.bounds.size.width, kNavBarHeight);
navBar.frame = navBarFrame;
}
if (scrollView.contentOffset.y < -kNavBarHeight)
{
[webview.scrollView setScrollIndicatorInsets:UIEdgeInsetsMake(fabsf(scrollView.contentOffset.y), 0, 0, 0)];
}
}
}
- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
{
if (scrollView == webview.scrollView)
{
webViewScrollIsDragging = YES;
}
}
- (void) scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate
{
if (scrollView == webview.scrollView)
{
webViewScrollIsDragging = NO;
}
}
- (void) scrollViewWillBeginDecelerating:(UIScrollView *)scrollView
{
if (scrollView == webview.scrollView)
{
webViewScrollIsDecelerating = YES;
}
}
- (void) scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
if (scrollView == webview.scrollView)
{
webViewScrollIsDecelerating = NO;
}
}
回答by eduludi
Easy as add this on the ViewController implementation file (.m):
很容易在 ViewController 实现文件 (.m) 上添加它：
- (void)viewDidLoad
{
[super viewDidLoad];
self.webView.scrollView.delegate = self;
}
#pragma mark - UIScrollViewDelegate Methods
- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
{
self.lastOffsetY = scrollView.contentOffset.y;
}
- (void) scrollViewWillBeginDecelerating:(UIScrollView *)scrollView
{
bool hide = (scrollView.contentOffset.y > self.lastOffsetY);
[[self navigationController] setNavigationBarHidden:hide animated:YES];
}
AND don't forget to add UIScrollViewDelegateprotocol in the header file (.h) :
并且不要忘记UIScrollViewDelegate在头文件 (.h) 中添加协议：
@interface MyViewController : UIViewController <UIScrollViewDelegate>
...
@end
回答by mamian
In iOS8.0 and later just use one line code:
在 iOS8.0 及更高版本中只需使用一行代码：
self.navigationController.hidesBarsOnSwipe = YES;
/// When the user swipes, the navigation controller's navigationBar & toolbar will be hidden (on a swipe up) or shown (on a swipe down). The toolbar only participates if it has items.
// @property (nonatomic, readwrite, assign) BOOL hidesBarsOnSwipe NS_AVAILABLE_IOS(8_0) __TVOS_PROHIBITED;
When sliding down will hide the navigation bar (and become a transparent state bar), when the slide will be displayed on the navigation bar, the process with animation
向下滑动时会隐藏导航栏（并变成透明状态栏），当滑动时会显示在导航栏上，该过程带有动画
