在做视频开发时遇到屏幕旋转问题,其中涉及到 StatusBar、 UINavigationController、UITabBarController 、UIViewcontroller。
在设备锁屏下的整体效果图
iOS-旋转.gif
主要涉及以下4点：
- 横竖屏的旋转
- 屏幕旋转相应改变视图位置
- 旋转时状态栏的隐藏与显示
- 锁屏
1、横竖屏旋转
-
第1步：
-(UIInterfaceOrientationMask)application:(UIApplication *)application supportedInterfaceOrientationsForWindow:(UIWindow *)window { // NSLog(@"0000000---------%@",NSStringFromClass([[self topViewController] class])); // if ([NSStringFromClass([[self topViewController] class]) isEqualToString:@"FirstViewController"]) { // //横屏 // return UIInterfaceOrientationMaskLandscapeRight; // } // //竖屏 // return UIInterfaceOrientationMaskPortrait; NSUInteger orientations = UIInterfaceOrientationMaskAllButUpsideDown; if(self.window.rootViewController){ //取出当前显示的控制器 UIViewController *presentedViewController = [self topViewControllerWithRootViewController:self.window.rootViewController]; //按当前控制器支持的方向确定旋转方向(将旋转方向重新交给每个控制器自己控制) NSLog(@"%s, line = %d",__FUNCTION__,__LINE__); orientations = [presentedViewController supportedInterfaceOrientations]; } return orientations; } //获取界面最上层的控制器 //- (UIViewController*)topViewController { // NSLog(@"%s, line = %d",__FUNCTION__,__LINE__); // return [self topViewControllerWithRootViewController:[UIApplication sharedApplication].keyWindow.rootViewController]; //} //一层一层的进行查找判断 - (UIViewController*)topViewControllerWithRootViewController:(UIViewController*)rootViewController { NSLog(@"%s, line = %d",__FUNCTION__,__LINE__); if ([rootViewController isKindOfClass:[UITabBarController class]]) { UITabBarController* tabBarController = (UITabBarController*)rootViewController; NSLog(@"Tabbar:%@",NSStringFromClass([tabBarController.selectedViewController class])); return [self topViewControllerWithRootViewController:tabBarController.selectedViewController]; } else if ([rootViewController isKindOfClass:[UINavigationController class]]) { UINavigationController* nav = (UINavigationController*)rootViewController; NSLog(@"nav:%@",NSStringFromClass([nav.visibleViewController class])); return [self topViewControllerWithRootViewController:nav.visibleViewController]; } else if (rootViewController.presentedViewController) { NSLog(@"present:%@",NSStringFromClass([rootViewController.presentationController class])); UIViewController* presentedViewController = rootViewController.presentedViewController; return [self topViewControllerWithRootViewController:presentedViewController]; } else { NSLog(@"root:%@",rootViewController); return rootViewController; } }
代码中通过 -(UIInterfaceOrientationMask)application:(UIApplication *)application supportedInterfaceOrientationsForWindow:(UIWindow *)window 方法将控制器交给自己控制，该方法默认值为Info.plist中配置的Supported interface orientations项的值。
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第2步：在各控制器设置支持的方向
//是否允许旋转(默认允许) - (BOOL)shouldAutorotate { return YES; } - (UIInterfaceOrientationMask)supportedInterfaceOrientations{ //允许旋转的方向 return UIInterfaceOrientationMaskAll; }其中
- supportedInterfaceOrientations方法在 iPad 中默认取值为UIInterfaceOrientationMaskAll，即默认支持所有屏幕方向；而 iPhone 跟 iPod Touch 的默认取值为UIInterfaceOrientationMaskAllButUpsideDown，即支持除竖屏向下以外的三个方向。
在设备屏幕旋转时，系统会调用- shouldAutorotate方法检查当前界面是否支持旋转，只有- shouldAutorotate返回YES的时候，- supportedInterfaceOrientations方法才会被调用，以确定是否需要旋转界面。
这个是TabbarController中设置的,它会影响关联的UIViewController的支持方向，需要在UIViewController中进一步设置//此方法来控制能否横竖屏 控制锁屏 - (UIInterfaceOrientationMask)supportedInterfaceOrientations { NSLog(@"%s, line = %d",__FUNCTION__,__LINE__); UIInterfaceOrientationMask inter; if (_lockScreen) { switch (_lockOrientation) { case 1: inter = UIInterfaceOrientationMaskPortrait; break; case 2: inter = UIInterfaceOrientationMaskPortraitUpsideDown; break; case 3: inter = UIInterfaceOrientationMaskLandscapeRight; break; case 4: inter = UIInterfaceOrientationMaskLandscapeLeft; break; default:inter = UIInterfaceOrientationMaskAll; break; } } else { inter = UIInterfaceOrientationMaskAll; } //支持全部方向 return inter; } -
第3步：强制转换控制器方向
- (void)setInterOrientation:(UIInterfaceOrientation)orientation { if ([[UIDevice currentDevice] respondsToSelector:@selector(setOrientation:)]) { SEL selector = NSSelectorFromString(@"setOrientation:"); NSInvocation *invocation = [NSInvocation invocationWithMethodSignature:[UIDevice instanceMethodSignatureForSelector:selector]]; [invocation setSelector:selector]; [invocation setTarget:[UIDevice currentDevice]]; int val = orientation; // 从2开始是因为0 1 两个参数已经被selector和target占用 [invocation setArgument:&val atIndex:2]; [invocation invoke]; } }这样就可以完成横竖屏的切换。
2、屏幕旋转相应改变视图位置
这里先扩展UIDeviceOrientation & UIInterfaceOrientation的知识
-
UIDeviceOrientation设备的物理方向
UIDeviceOrientation即我们手持的移动设备的Orientation，是一个三围空间,有六个方向,通过[UIDevice currentDevice].orientation获取当前设备的方向。typedef NS_ENUM(NSInteger, UIDeviceOrientation) { UIDeviceOrientationUnknown, UIDeviceOrientationPortrait, UIDeviceOrientationPortraitUpsideDown, // Device oriented vertically, home button on the top 竖屏向下，即头在下，Home 键在上 UIDeviceOrientationLandscapeLeft, // Device oriented horizontally, home button on the right 横屏头在左，Home键在右 UIDeviceOrientationLandscapeRight, // Device oriented horizontally, home button on the left 横屏头在右，Home键在左 UIDeviceOrientationFaceUp, // Device oriented flat, face up UIDeviceOrientationFaceDown // Device oriented flat, face down } ; -
UIInterfaceOrientation界面的显示方向
UIInterfaceOrientation即我们看到的视图的Orientation，可以理解为statusBar所在的方向，是一个二维空间，有四个方向, 通过[UIApplication sharedApplication].statusBarOrientation即状态栏的方向获取当前界面方向。// Note that UIInterfaceOrientationLandscapeLeft is equal to UIDeviceOrientationLandscapeRight (and vice versa). // This is because rotating the device to the left requires rotating the content to the right. typedef NS_ENUM(NSInteger, UIInterfaceOrientation) { UIInterfaceOrientationUnknown = UIDeviceOrientationUnknown, UIInterfaceOrientationPortrait = UIDeviceOrientationPortrait, UIInterfaceOrientationPortraitUpsideDown = UIDeviceOrientationPortraitUpsideDown, UIInterfaceOrientationLandscapeLeft = UIDeviceOrientationLandscapeRight, UIInterfaceOrientationLandscapeRight = UIDeviceOrientationLandscapeLeft } -
UIInterfaceOrientationMask支持的方向// iOS 6 之后用于控制界面的枚举值 typedef NS_OPTIONS(NSUInteger, UIInterfaceOrientationMask) { UIInterfaceOrientationMaskPortrait = (1 << UIInterfaceOrientationPortrait), UIInterfaceOrientationMaskLandscapeLeft = (1 << UIInterfaceOrientationLandscapeLeft), UIInterfaceOrientationMaskLandscapeRight = (1 << UIInterfaceOrientationLandscapeRight), UIInterfaceOrientationMaskPortraitUpsideDown = (1 << UIInterfaceOrientationPortraitUpsideDown), UIInterfaceOrientationMaskLandscape = (UIInterfaceOrientationMaskLandscapeLeft | UIInterfaceOrientationMaskLandscapeRight), UIInterfaceOrientationMaskAll = (UIInterfaceOrientationMaskPortrait | UIInterfaceOrientationMaskLandscapeLeft | UIInterfaceOrientationMaskLandscapeRight | UIInterfaceOrientationMaskPortraitUpsideDown), UIInterfaceOrientationMaskAllButUpsideDown = (UIInterfaceOrientationMaskPortrait | UIInterfaceOrientationMaskLandscapeLeft | UIInterfaceOrientationMaskLandscapeRight), }
由上可以发现：
- iOS 6 及之后版本使用的
UIInterfaceOrientationMask类型来控制屏幕屏幕方向，该类型也新增加了几个枚举取值，可用一个枚举取值来代表多个屏幕方向，使用起来更方便。 - 注意在
UIInterfaceOrientation中有注释 Note that UIInterfaceOrientationLandscapeLeft is equal to UIDeviceOrientationLandscapeRight (and vice versa).
This is because rotating the device to the left requires rotating the content to the right，大意是界面的左转相当于设备的右转，如果设备向左转时就需要内容（即界面）向右转。即：
UIInterfaceOrientationLandscapeLeft = UIDeviceOrientationLandscapeRight
UIInterfaceOrientationLandscapeRight = UIDeviceOrientationLandscapeLeft
下面还会举例说明。
其实UIDeviceOrientation与UIInterfaceOrientation是两个互不相干的属性，通常情况下会一起出现，在这里正好利用此特性在屏幕旋转后进行重新布局。
-
第1步：监听
UIDeviceOrientationDidChangeNotification状态//监听设备旋转 改变 视图 对应位置 [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(deviceOrientationDidChange) name:UIDeviceOrientationDidChangeNotification object:nil]; //用来控制横竖屏时调整视图位置 - (void)deviceOrientationDidChange { [self isPortrait]; } -
第2步：重新布局
if (_interOrientation == UIInterfaceOrientationPortrait || _interOrientation == UIInterfaceOrientationPortraitUpsideDown) { self.top.constant = 145; self.bottom.constant = 210; } else if (_interOrientation == UIInterfaceOrientationLandscapeRight || _interOrientation == UIInterfaceOrientationLandscapeLeft) { self.top.constant = 40; self.bottom.constant = 50; }
例如：竖屏转横屏
界面竖屏UIInterfaceOrientationPortrait ->横屏UIInterfaceOrientationLandscapeRight，设备方向UIDeviceOrientationPortrait->UIDeviceOrientationLandscapeLeft,在设备发生变化这个过程触发UIDeviceOrientationDidChangeNotification监听，然后进行重新布局。
3、旋转时状态栏的隐藏与显示
-
这里只记述旋转时状态栏的变化，由竖屏想横屏变化时状态栏会消失。
//在需要的`UIViewController`设置是否隐藏 - (BOOL)prefersStatusBarHidden { NSLog(@"%s, line = %d",__FUNCTION__,__LINE__); return NO; }
4、锁屏
锁屏时，不管系统锁屏是否关闭、Push 或 Present 返回后，界面依然保持不变。
-
第1步：设置锁屏
- (IBAction)lockAction:(UIButton *)sender { if (_lockScreen) { _lockScreen = NO; [sender setTitle:@"锁定屏幕" forState:UIControlStateNormal]; } else { _lockScreen = YES; [sender setTitle:@"解开屏幕" forState:UIControlStateNormal]; } _lockOrientation = _interOrientation; } -
第2步：绕过强转
- (void)interfaceOrientation:(UIInterfaceOrientation)orientation { [self isPortrait]; //锁屏情况下 不旋转 if (!_lockScreen) { [self setInterOrientation:orientation]; } -
第3步：针对 Push 或 Present 返回后
- (void)viewWillAppear:(BOOL)animated { if (_lockScreen) { //记录返回时的界面状态 [self setInterOrientation:_lockOrientation]; } else { [self isPortrait]; } }
5、 针对特定UIViewController方向的支持
-(UIInterfaceOrientationMask)application:(UIApplication *)application supportedInterfaceOrientationsForWindow:(UIWindow *)window {
if ([NSStringFromClass([[self topViewController] class]) isEqualToString:@"FirstViewController"]) {
//横屏
return UIInterfaceOrientationMaskLandscapeRight;
}
//竖屏
return UIInterfaceOrientationMaskPortrait;
}
最后的献上GitHub代码，还有2个小的 bug ，有兴趣的朋友欢迎来探讨。
- 参考文章：
iOS 屏幕旋转问题总结
iOS 屏幕方向那点事儿
