UIWindow with wrong size when using landscape orie

问题:

I have an empty application and there is no storyboard or xib involved. I want to have a hidden status bar and support only landscape orientation. Again, I wan't to make those changes only within code and don't touch the Info.plist.

Problem

I create a UIWindow with a controller that says the only supported orientation is landscape. In that case my UIWindow is created in the dimension of portrait mode and doesn't rotate. The expected result would be a screen that is completely cyan.

This is my delegate:

#import "AppDelegate.h"
#import "AppViewController.h"

@implementation AppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
  self.window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];
  self.window.backgroundColor = [UIColor cyanColor];
  self.window.rootViewController = [[AppViewController alloc] init];
  [self.window makeKeyAndVisible];
  return YES;
}

@end

This is my controller:

#import "AppViewController.h"

@implementation AppViewController

- (BOOL)shouldAutorotate {
  return YES;
}

- (UIInterfaceOrientation)preferredInterfaceOrientationForPresentation {
  return UIInterfaceOrientationLandscapeLeft;
}

- (BOOL)prefersStatusBarHidden {
  return YES;
}

- (NSUInteger)supportedInterfaceOrientations {
  return UIInterfaceOrientationMaskLandscape;
}

@end

What I've tried so far

If I set the rootViewController after calling makeKeyAndVisible everything seems to work at first.

self.window.backgroundColor = [UIColor cyanColor];
[self.window makeKeyAndVisible];
self.window.rootViewController = [[AppViewController alloc] init];

There are still some issues. First of all I don't like this since it seems to be very fragile. Second problem is that in a more complex application that sets a GLKViewController as the rootViewController I get the following result (expected would be no black area on the left):

It looks like the status bar is not hidden early enough. Several gesture recognizers are active and in the GLKViewController and clicking on the black area yields the following log message:

2014-09-25 13:20:42.170 StackOverflowExample[6971:107907] unexpected nil window in _UIApplicationHandleEventFromQueueEvent, _windowServerHitTestWindow: UIClassicWindow: 0x7fa20b805e00; frame = (0 0; 375 667); userInteractionEnabled = NO; gestureRecognizers = NSArray: 0x7fa20b80a620; layer = UIWindowLayer: 0x7fa20b806890

I also performed various other changes, like attaching an empty UIViewController and adding my view as a sub-view. In that case my view looks correct but the window is still using the wrong dimensions.

Everything rotates correct if I do not override the supportedInterfaceOrientations methods in my view controller. But that is of course not what I want.

回答1:

When you run landscape app from portrait mode UIScreen has portrait bounds in iOS 8 (only if you haven't this app in app switch panel, as iOS 8 makes some cache). Even displaying window with makeKeyAndVisible doesn't change it's frame. But it changes [UIScreen mainScreen].bounds according to AppViewController avaliable orientation.

#import "AppDelegate.h"
#import "AppViewController.h"

@implementation AppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
  // Portrait bounds at this point
  self.window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];

  self.window.backgroundColor = [UIColor cyanColor];
  self.window.rootViewController = [[AppViewController alloc] init];
  [self.window makeKeyAndVisible];
  return YES;
}

@end

So let's change window's frame after [self.window makeKeyAndVisible]

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    self.window = [UIWindow new];
    self.window.backgroundColor = [UIColor cyanColor];
    self.window.rootViewController = [[AppViewController alloc] init];
    [self.window makeKeyAndVisible];

    // Here it is
    self.window.frame = [UIScreen mainScreen].bounds;
    return YES;
}

I think that it is iOS 8 bug.

回答2:

I had a similar problem, for a portrait-only app.

I fixed the problem by setting status bar orientation BEFORE instantiate the UIWindow

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    // Init my stuff
    // ...

    // Prepare window
    [application setStatusBarOrientation:UIInterfaceOrientationPortrait animated:NO]; // prevent start orientation bug
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    [self.window makeKeyAndVisible];
    return YES;
}

In your case, you should use UIInterfaceOrienationLandscapeLeft (or Right) in the setStatusBarOrientation:animated: method.

Hope it helps you.

回答3:

Personally, none of the solution presented above worked. I finally set "hidden" to YES for the window in my main xib, as first suggested here: unexpected nil window in _UIApplicationHandleEventFromQueueEvent, _windowServerHitTestWindow

回答4:

The problem is solved when adding a Launch Screen, which you can only do by adding an extra property to the info.plist

had this problem myself, i'm not sure if you can add it through code though, i only managed to make it work with info.plist + Launch Screen xib file

<key>UILaunchStoryboardName</key>
<string>Launch Screen</string>

Actually i don't think you have to add a xib file, if just the key (with any value) is available in the plist it should work.

回答5:

None of the solutions posted here or elsewhere worked for me.

However, I found that this issue apparently does not occur with Storyboards, so an alternative solution is to move away from xibs. (This fact sadly also makes it unlikely that Apple will take the problem seriously.)