MPMoviePlayerController导致Cocos2D中出现约束警告

Question

我正在为iOS开发Cocos2D游戏，在控制台中看到了很多与约束相关的警告。我在SO和其他网站上读过很多与约束相关的帖子，但都没能解决这个问题。

我没有NIB文件，也没有在这个项目中使用XCodes用户界面生成器。Cocos2D只是使用了一个以编程方式创建的全屏GLView。据我所知，所有这些约束都来自MPMoviePlayerController与UIView本身的交互。

我正在使用以下代码进行MPMoviePlayerController集成：https://github.com/cocos2d/cocos2d-iphone-extensions/blob/master/Extensions/CCVideoPlayer/iOS/CCVideoPlayerImpliOS.m

进行了一些细微的更改，以显示非全屏视频，并使其在iOS8:上编译

- (void) setupViewAndPlay
{
    UIWindow *keyWindow = [[UIApplication sharedApplication] keyWindow];    
    CGSize viewSize = [[CCDirector sharedDirector] viewSizeInPixels];
    // We want to show these animations windowed - not full screen
    // Native resolution of the movie is 480p = 640x360
    CGRect videoFrame = CGRectMake( 0, 0, 640, 360);
    if (viewSize.height < 768)
    {
        // On the iphone play at 1/2 size
        videoFrame = CGRectMake(0, 0, 320, 180);
    }
    videoFrame.origin.x = (viewSize.width - videoFrame.size.width) / 2.0f;
    videoFrame.origin.y = (viewSize.height - videoFrame.size.height) / 2.0f;
   [keyWindow addSubview: [_theMovie view]];
    [[_theMovie view] setHidden:  NO];
    [[_theMovie view] setFrame: videoFrame];
    [[_theMovie view] setCenter: keyWindow.center ];
    [keyWindow setAutoresizesSubviews:NO];
    [self updateOrientationWithOrientation: (UIDeviceOrientation)[[UIApplication sharedApplication] statusBarOrientation]];
    // Movie playback is asynchronous, so this method returns immediately.
    [_theMovie play];
}

以下是我看到的警告：

2014-10-01 11:32:45.360 SpaceBotAlpha[182:4484] Unable to simultaneously satisfy constraints.
    Probably at least one of the constraints in the following list is one you don't want. Try this: (1) look at each constraint and try to figure out which you don't expect; (2) find the code that added the unwanted constraint or constraints and fix it. (Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints) 
(
    "<NSLayoutConstraint:0x17774f20 H:|-(34)-[MPKnockoutButton:0x177db4e0](LTR)    (Names: '|':_UIBackdropContentView:0x18c7e040 )>",
    "<NSLayoutConstraint:0x17774f50 H:[MPKnockoutButton:0x177db4e0]-(34)-[MPDetailSlider:0x18cb1f60](LTR)>",
    "<NSLayoutConstraint:0x17774f80 H:[MPDetailSlider:0x18cb1f60]-(34)-[UIView:0x18cb6780](LTR)>",
    "<NSLayoutConstraint:0x17774fb0 UIView:0x18cb6780.right == _UIBackdropView:0x18caec50.right - 34>",
    "<NSLayoutConstraint:0x18cafac0 H:|-(0)-[_UIBackdropView:0x18caec50]   (Names: '|':MPVideoPlaybackOverlayView:0x1778ad80 )>",
    "<NSLayoutConstraint:0x18cc77b0 H:[_UIBackdropView:0x18caec50]-(0)-|   (Names: '|':MPVideoPlaybackOverlayView:0x1778ad80 )>",
    "<NSAutoresizingMaskLayoutConstraint:0x1776da10 h=-&- v=-&- _UIBackdropContentView:0x18c7e040.midX == _UIBackdropView:0x18caec50.midX>",
    "<NSAutoresizingMaskLayoutConstraint:0x1776da40 h=-&- v=-&- _UIBackdropContentView:0x18c7e040.width == _UIBackdropView:0x18caec50.width>",
    "<NSAutoresizingMaskLayoutConstraint:0x177aa050 h=-&- v=-&- MPVideoPlaybackOverlayView:0x1778ad80.width == MPVideoContainerView:0x1778b8e0.width>",
    "<NSAutoresizingMaskLayoutConstraint:0x1775e480 h=-&- v=-&- MPVideoContainerView:0x1778b8e0.width == MPSwipableView:0x18cba6f0.width>",
    "<NSAutoresizingMaskLayoutConstraint:0x177a8ce0 h=-&- v=-&- MPSwipableView:0x18cba6f0.width == MPMovieView:0x177c7eb0.width>",
    "<NSAutoresizingMaskLayoutConstraint:0x17766310 h=--& v=--& H:[MPMovieView:0x177c7eb0(0)]>"
)
Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x17774f50 H:[MPKnockoutButton:0x177db4e0]-(34)-[MPDetailSlider:0x18cb1f60](LTR)>
Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> may also be helpful.

我发现的所有关于约束的帖子都假设已经使用了接口生成器。

有线索吗？谢谢

---

万一有人发现这篇文章在寻找关于旋转的信息：我注意到一些奇怪的事情，在iOS8上，MPMoviePlayerController似乎会自动旋转到正确的方向，如果我保持updateOrientationWithOrientation方法不变（请参阅GitHub链接），那么它会以90度的角度出现。因此，在iOS8上，我检测到updateOrientationWithOrientation中的版本，然后退出，而不对iOS8执行任何操作。

Answer 1

我遇到了同样的约束问题。然而，赛兹的回答对我来说并不奏效，所以我深入研究了一下。在我的案例中，问题是在设置视频控制器视图的帧并将其添加到超级视图之前调用[videoConroller prepareToPlay]。

我正在创建我的MPMoviePlayerController的实例，并在viewDidLoad中调用prepareToPlay，因为此时我有url。然而，我一直在等待viewDidPappear来实际调整视频播放器的大小，并将其添加到视图层次结构中。

在将视图添加到层次结构后，只需将该方法调用移动到就解决了我的问题。此外，我还可以得到一个与父视图的边界不匹配的帧。

Answer 2

您是否尝试使用MPMoviePlayerViewController而不是MPMoviePlayerController？（对我有效：-）然后将translatesAutoresizingMaskIntoConstraints设置为YES。就像这样：

     MPMoviePlayerViewController *moviePlayerViewController = [MPMoviePlayerViewController new];
    [moviePlayerViewController.view setTranslatesAutoresizingMaskIntoConstraints:YES];

我希望这对你有用！。。

Answer 3

好吧，我最终解决了这个问题，去掉了我试图破解的CCVideoPlayer扩展，直接使用MPMoviePlayerController。当我开始做Mac时，我必须推出一个新的解决方案。

摆脱约束消息的关键是电影视图的窗口大小必须与其超级视图大小相匹配。为了做到这一点，我在代码中构建了一个具有正确大小和位置的UIView，并使MPMoviePlayerController的视图成为它的子视图。

这是代码的一部分：

_videoFrameView = [[UIView alloc] initWithFrame:frameUI];
[_videoFrameView setBackgroundColor:[UIColor redColor]];
[mainView addSubview:_videoFrameView];
_movie = [[MPMoviePlayerController alloc] init];
[_movie setRepeatMode:(MPMovieRepeatModeNone)];
[_movie setControlStyle:MPMovieControlStyleNone];
[_movie setScalingMode:MPMovieScalingModeAspectFit];
[_movie setMovieSourceType:(MPMovieSourceTypeStreaming)];
CGRect movieFrame;
movieFrame.size = frameUI.size;
[[_movie view] setFrame:movieFrame]; // player's frame size must match parent's
[_videoFrameView addSubview: [_movie view]];
[_videoFrameView bringSubviewToFront:[_movie view]];

更详细的粘贴方法显示在这个要点中。我的方法基于另一个答案中的想法。

Answer 4

在iOS 9.1.2中，解决了以下行。此外，警告反复打印，直到我重新启动应用程序。这些线解决了这个问题。

moviePlayerController = [[MPMoviePlayerController alloc]initWithContentURL:videoUrl];
    [moviePlayerController.view setTranslatesAutoresizingMaskIntoConstraints:NO];