我有一个适用于 iOS 8/9 的通用应用程序,其中包含 MainStoryboard_iPhone 和 MainStoryboard_iPad。故事板中的入口点是一个带有标签栏的 RootViewController。RootViewController 控制器非常简单
- (void)viewDidLoad
{
[(VIBAppDelegate *)[[UIApplication sharedApplication] delegate] setRootViewController:self];
self.interfaceOrientationMask = UIInterfaceOrientationMaskAll;
self.preferredOrientation = UIInterfaceOrientationMaskAll;
[super viewDidLoad];}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
}
- (UIInterfaceOrientationMask)supportedInterfaceOrientations{
return self.interfaceOrientationMask;
}
- (BOOL)shouldAutorotate{
return YES;
}
- (UIInterfaceOrientation)preferredInterfaceOrientationForPresentation{
UIViewController *currentVC = self.selectedViewController;
if ([currentVC respondsToSelector:@selector(preferredInterfaceOrientationForPresentation)]) {
UIInterfaceOrientation orientation = [currentVC preferredInterfaceOrientationForPresentation];
return orientation;
}else{
return self.preferredOrientation;
}
}
当我在 iPhone 上启动这个应用程序时,supportedInterfaceOrientation 和 shouldAutorotate 方法在应用程序启动期间和设备旋转时被调用。当我在 iPad 上启动应用程序时,它们永远不会被调用。在这两种情况下,viewDidLoad 函数都会按预期调用。
我已经为此困惑了好几个小时。除了布局之外,我认为故事板没有任何差异。两种设备类型都允许 Info.plist 文件中的所有 4 个方向和其他相关键。
<key>UIMainStoryboardFile</key>
<string>MainStoryboard_iPhone</string>
<key>UIMainStoryboardFile~ipad</key>
<string>MainStoryboard_iPad</string>
<key>UIStatusBarHidden</key>
<true/>
<key>UIStatusBarHidden~ipad</key>
<true/>
<key>UIStatusBarStyle</key>
<key>UISupportedInterfaceOrientations</key>
<array>
<string>UIInterfaceOrientationPortrait</string>
<string>UIInterfaceOrientationLandscapeLeft</string>
<string>UIInterfaceOrientationLandscapeRight</string>
<string>UIInterfaceOrientationPortraitUpsideDown</string>
</array>
<key>UISupportedInterfaceOrientations~ipad</key>
<array>
<string>UIInterfaceOrientationPortrait</string>
<string>UIInterfaceOrientationPortraitUpsideDown</string>
<string>UIInterfaceOrientationLandscapeLeft</string>
<string>UIInterfaceOrientationLandscapeRight</string>
</array>
在 shouldAutorotate 函数处设置断点表明 UIWindow _shouldAutorotateToInterfaceOrientation:checkForDismissal:is... 正在调用该函数,UIApplicationMain 调用了该函数。这正如预期的那样。