问题描述
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我有一个带有多个视图的标签栏控制器。每个视图都有一个工具栏。我添加了将背景图像应用于工具栏的代码。
我还在每个视图上的viewdidLoad中添加了代码,以在设备旋转时触发,因此我可以为横向模式应用不同的背景图片:
[[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
NSNotificationCenter *notificationCenter = [NSNotificationCenter defaultCenter];
[notificationCenter addObserver:self selector:@selector(didRotate:)
name:@\"UIDeviceOrientationDidChangeNotification\" object:nil];
如果我运行该应用程序并旋转,则第一个视图有效,但随后转到其他选项卡将导致didRotate方法不触发,因为设备已经旋转。
设备旋转时如何使所有视图更新?
解决方法
您不一定需要通知。您可以使用两种方法来完成此操作
- (void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toOrientation
duration:(NSTimeInterval)duration
和
-(void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation
例如,要使tabBar在横向模式下隐藏而不在纵向模式下隐藏,请使用以下命令:
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
return YES;
}
- (void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toOrientation
duration:(NSTimeInterval)duration
{
if (toOrientation == UIInterfaceOrientationLandscapeLeft ||
toOrientation == UIInterfaceOrientationLandscapeRight) {
[[self view] endEditing:YES];
[[self view] addSubview:graphView];
//[[UIApplication sharedApplication] setStatusBarHidden:TRUE withAnimation:FALSE];
[[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleBlackOpaque];
[self.navigationController setNavigationBarHidden:TRUE animated:TRUE];
}
}
-(void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation
{
UIInterfaceOrientation toOrientation = self.interfaceOrientation;
if ( self.tabBarController.view.subviews.count >= 2 )
{
UIView *transView = [self.tabBarController.view.subviews objectAtIndex:0];
UIView *tabBar = [self.tabBarController.view.subviews objectAtIndex:1];
if(toOrientation == UIInterfaceOrientationLandscapeLeft ||
toOrientation == UIInterfaceOrientationLandscapeRight) {
transView.frame = CGRectMake(0,480,320 );
tabBar.hidden = TRUE;
}
else
{
transView.frame = CGRectMake(0,320,480);
tabBar.hidden = FALSE;
}
}
}
,您应该做的是在viewWillAppear:
上选中interfaceOrientation
,并在需要时重新布局UI。