在做視頻開發時遇到屏幕旋轉問題,其中涉及到 StatusBar、 UINavigationController、UITabBarController 、UIViewcontroller 。
在設備鎖屏下的整體效果圖
iOS-旋轉.gif
主要涉及以下4點：
1、橫豎屏旋轉
第1步：
-(UIInterfaceOrientationMask)application:(UIApplication *)application supportedInterfaceOrientationsForWindow:(UIWindow *)window {
// NSLog(@"0000000---------%@",NSStringFromClass([[self topViewController] class]));
// if ([NSStringFromClass([[self topViewController] class]) isEqualToString:@"FirstViewController"]) {
// //橫屏
// return UIInterfaceOrientationMaskLandscapeRight;
// }
// //豎屏
// return UIInterfaceOrientationMaskPortrait;
NSUInteger orientations = UIInterfaceOrientationMaskAllButUpsideDown;
if(self.window.rootViewController){
//取出當前顯示的控制器
UIViewController *presentedViewController = [self topViewControllerWithRootViewController:self.window.rootViewController];
//按當前控制器支持的方向確定旋轉方向(將旋轉方向重新交給每個控制器自己控制)
NSLog(@"%s, line = %d",__FUNCTION__,__LINE__);
orientations = [presentedViewController supportedInterfaceOrientations];
}
return orientations;
}
//獲取界面最上層的控制器
//- (UIViewController*)topViewController {
// NSLog(@"%s, line = %d",__FUNCTION__,__LINE__);
// return [self topViewControllerWithRootViewController:[UIApplication sharedApplication].keyWindow.rootViewController];
//}
//一層一層的進行查找判斷
- (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;
}
}
代碼中通過 -(UIInterfaceOrientationMask)application:(UIApplication *)application supportedInterfaceOrientationsForWindow:(UIWindow *)window 方法將控制器交給自己控制，該方法默認值為 Info.plist 中配置的 Supported interface orientations 項的值。
第2步：在各控制器設置支持的方向
//是否允許旋轉(默認允許)
- (BOOL)shouldAutorotate {
return YES;
}
- (UIInterfaceOrientationMask)supportedInterfaceOrientations{
//允許旋轉的方向
return UIInterfaceOrientationMaskAll;
}
其中 - supportedInterfaceOrientations 方法在 iPad 中默認取值為 UIInterfaceOrientationMaskAll ，即默認支持所有屏幕方向；而 iPhone 跟 iPod Touch 的默認取值為 UIInterfaceOrientationMaskAllButUpsideDown ，即支持除豎屏向下以外的三個方向。
在設備屏幕旋轉時，系統會調用 - shouldAutorotate 方法檢查當前界面是否支持旋轉，只有 - shouldAutorotate 返回 YES 的時候， - supportedInterfaceOrientations 方法才會被調用，以確定是否需要旋轉界面。
這個是 TabbarController 中設置的,它會影響關聯的 UIViewController 的支持方向，需要在 UIViewController 中進一步設置
//此方法來控制能否橫豎屏 控制鎖屏
- (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：強制轉換控制器方向
- (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;
// 從2開始是因為0 1 兩個參數已經被selector和target占用
[invocation setArgument:&val atIndex:2];
[invocation invoke];
}
}
這樣就可以完成橫豎屏的切換。
2、屏幕旋轉相應改變視圖位置
這里先擴展 UIDeviceOrientation & UIInterfaceOrientation 的知識
UIDeviceOrientation 設備的物理方向
UIDeviceOrientation 即我們手持的移動設備的 Orientation ，是一個三圍空間,有六個方向,通過 [UIDevice currentDevice].orientation 獲取當前設備的方向。
typedef NS_ENUM(NSInteger, UIDeviceOrientation) {
UIDeviceOrientationUnknown,
UIDeviceOrientationPortrait,
UIDeviceOrientationPortraitUpsideDown, // Device oriented vertically, home button on the top 豎屏向下，即頭在下，Home 鍵在上
UIDeviceOrientationLandscapeLeft, // Device oriented horizontally, home button on the right 橫屏頭在左，Home鍵在右
UIDeviceOrientationLandscapeRight, // Device oriented horizontally, home button on the left 橫屏頭在右，Home鍵在左
UIDeviceOrientationFaceUp, // Device oriented flat, face up
UIDeviceOrientationFaceDown // Device oriented flat, face down
} ;
UIInterfaceOrientation 界面的顯示方向
UIInterfaceOrientation 即我們看到的視圖的 Orientation ，可以理解為 statusBar 所在的方向，是一個二維空間，有四個方向, 通過 [UIApplication sharedApplication].statusBarOrientation 即狀態欄的方向獲取當前界面方向。
// 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舉值
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),
}
由上可以發現：
iOS 6 及之后版本使用的 UIInterfaceOrientationMask 類型來控制屏幕屏幕方向，該類型也新增加了幾個枚舉取值，可用一個枚舉取值來代表多個屏幕方向，使用起來更方便。
注意在 UIInterfaceOrientation 中有注釋
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，大意是界面的左轉相當于設備的右轉，如果設備向左轉時就需要內容（即界面）向右轉。即：
UIInterfaceOrientationLandscapeLeft = UIDeviceOrientationLandscapeRight
UIInterfaceOrientationLandscapeRight = UIDeviceOrientationLandscapeLeft
下面還會舉例說明。
其實 UIDeviceOrientation 與 UIInterfaceOrientation 是兩個互不相干的屬性，通常情況下會一起出現，在這里正好利用此特性在屏幕旋轉后進行重新布局。
第1步：監聽 UIDeviceOrientationDidChangeNotification 狀態
//監聽設備旋轉 改變 視圖 對應位置
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(deviceOrientationDidChange) name:UIDeviceOrientationDidChangeNotification object:nil];
//用來控制橫豎屏時調整視圖位置
- (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：豎屏轉橫屏
界面豎屏 UIInterfaceOrientationPortrait ->橫屏 UIInterfaceOrientationLandscapeRight ，設備方向 UIDeviceOrientationPortrait -> UIDeviceOrientationLandscapeLeft ,在設備發生變化這個過程觸發 UIDeviceOrientationDidChangeNotification 監聽，然后進行重新布局。
3、旋轉時狀態欄的隱藏與顯示
這里只記述旋轉時狀態欄的變化，由豎屏想橫屏變化時狀態欄會消失。
//在需要的`UIViewController`設置是否隱藏
- (BOOL)prefersStatusBarHidden {
NSLog(@"%s, line = %d",__FUNCTION__,__LINE__);
return NO;
}
4、鎖屏
鎖屏時，不管系統鎖屏是否關閉、Push 或 Present 返回后，界面依然保持不變。
第1步：設置鎖屏
- (IBAction)lockAction:(UIButton *)sender {
if (_lockScreen) {
_lockScreen = NO;
[sender setTitle:@"鎖定屏幕" forState:UIControlStateNormal];
} else {
_lockScreen = YES;
[sender setTitle:@"解開屏幕" forState:UIControlStateNormal];
}
_lockOrientation = _interOrientation;
}
第2步：繞過強轉
- (void)interfaceOrientation:(UIInterfaceOrientation)orientation
{
[self isPortrait];
//鎖屏情況下 不旋轉
if (!_lockScreen) {
[self setInterOrientation:orientation];
}
第3步：針對 Push 或 Present 返回后
- (void)viewWillAppear:(BOOL)animated {
if (_lockScreen) {
//記錄返回時的界面狀態
[self setInterOrientation:_lockOrientation];
} else {
[self isPortrait];
}
}
5、 針對特定 UIViewController 方向的支持
-(UIInterfaceOrientationMask)application:(UIApplication *)application supportedInterfaceOrientationsForWindow:(UIWindow *)window {
if ([NSStringFromClass([[self topViewController] class]) isEqualToString:@"FirstViewController"]) {
//橫屏
return UIInterfaceOrientationMaskLandscapeRight;
}
//豎屏
return UIInterfaceOrientationMaskPortrait;
}
最后的獻上 GitHub 代碼，還有2個小的 bug ，有興趣的朋友歡迎來探討。
以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持億速云。
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