應用本身只支援豎屏，當時又想讓應用中網頁視訊可以全屏播放，這種需求想必經常會有。

這裡提供一種方法，經過測試，能實現這種需求。

以下程式碼在Xcode7.1，iOS6~iOS9 測試通過。

首先在xxxxAppDelegate中增加一個屬性：

@property (nonatomic, assign) BOOL allowRotation; // 標記是否可以旋轉

.m檔案中實現方法：

- (UIInterfaceOrientationMask)application:(UIApplication *)application supportedInterfaceOrientationsForWindow:(UIWindow
 
 *)nowWindow {
    
    if (_allowRotation) {
        return UIInterfaceOrientationMaskAll;
    }
    else
    {
        return UIInterfaceOrientationMaskPortrait;
    }
}

Webview進入視訊播放頁面時候，系統會發出幾個通知：

UIMoviePlayerControllerDidEnterFullscreenNotification // 進入全屏播放

UIMoviePlayerControllerWillExitFullscreenNotification // 將退出全屏播放
 


UIMoviePlayerControllerDidExitFullscreenNotification // 已退出全屏播放

因此，可以在包含Webview的Controller的viewDidLoad方法中新增兩個通知監聽，分別是：

- (void)viewDidLoad
{
    [super viewDidLoad];
    if ([[[UIDevice currentDevice] systemVersion] floatValue] < 8.0f || [[[UIDevice currentDevice] systemVersion] floatValue] >= 9.0
 
f) {
        [[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(videoStarted:) name:@"UIMoviePlayerControllerDidEnterFullscreenNotification" object:nil];// 播放器即將播放通知
        [[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(videoFinished:) name:@"UIMoviePlayerControllerWillExitFullscreenNotification" object:nil];// 播放器即將退出通知
    }
    else
    {
        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(videoStarted:) name:UIWindowDidBecomeVisibleNotification object:nil];//進入全屏
        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(videoFinished:) name:UIWindowDidBecomeHiddenNotification object:nil];//退出全屏
    }
}

#pragma - mark  視訊進入全屏
-(void)videoStarted:(NSNotification *)notification
{
        xxxxAppDelegate *appDelegate = [UIApplication sharedApplication].delegate;
        appDelegate.allowRotation = YES;
}

#pragma - mark 視訊將退出
-(void)videoWillFinished:(NSNotification *)notification
{
    xxxxAppDelegate *appDelegate = [UIApplication sharedApplication].delegate;
    appDelegate.allowRotation = NO;
    
    // 強制歸正
    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 =UIInterfaceOrientationPortrait;
        [invocation setArgument:&val atIndex:2];
        [invocation invoke];
    }
}

Over。