Question

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到工具栏的代码。

我还在viewdidLoad中添加了代码，以便在旋转设备时触发每个视图，这样我就可以为横向模式应用不同的背景图像：

[[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];

NSNotificationCenter *notificationCenter = [NSNotificationCenter defaultCenter];
[notificationCenter addObserver:self selector:@selector(didRotate:)
name:@"UIDeviceOrientationDidChangeNotification" object:nil];

如果我运行应用程序并旋转，则第一个视图有效，但是转到其他选项卡会导致didRotate方法无法触发，因为设备已经旋转。

如何在设备旋转时更新所有视图？

Answer 1

您应该检查interfaceOrientation上的viewWillAppear:并根据需要重新布局用户界面。

Answer 2

您不一定需要通知。您可以使用两种方法完成此操作

- (void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toOrientation 
                                duration:(NSTimeInterval)duration

和

-(void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation

例如，要使tabBar隐藏在横向模式中而不是纵向隐藏，请使用：

- (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, 0, 480, 320 );
            tabBar.hidden = TRUE;
        }
        else
        {                               
            transView.frame = CGRectMake(0, 0, 320, 480);         
            tabBar.hidden = FALSE;
        }
    }
}

UITabBar更改旋转的所有视图

2 个答案: