c# - 获取错误断言失败 : movie player has wrong activation state (1) even though i use only one movie player

Question

我在 ViewController 中只使用了 1 个 MPMoviePlayerController。我正在做的是呈现一个 ViewController，其中我有一个 ScrollView ，其中有 4 - 5 个 subview ，用户可以在其中执行不同的操作，例如在 MPMoviePlayerController 中观看视频、键入一些文本、使用步进控件评价等

当用户转到 VC 观看视频并返回主 VC 并再次尝试返回时:

Getting Error Assertion failure: movie player has wrong activation state (1)

而且这个只发生在临时构建中。当我尝试在 Debug模式下重现它时，我只是看不到这个错误。这有点令人困惑。

查看下面的代码并提出更改建议。

我在一个方法中像这样初始化它。

     void SomeMethod(){

            this.MoviePlayer = new MPMoviePlayerController ();
            this.MoviePlayer.View.Frame = new RectangleF (AppConstants.ZeroVal,contentHeight, VIEW_WIDTH, 200);
            this.MoviePlayer.ControlStyle = MPMovieControlStyle.Default;
            this.MoviePlayer.SourceType = MPMovieSourceType.Streaming;
            this.MoviePlayer.ScalingMode = MPMovieScalingMode.Fill;
            this.MoviePlayer.ContentUrl = NSUrl.FromString(_someUrl_);
     }

在 Button 的 TouchUpInside 中

 btnObj.TouchUpInside+=((ss,ee)=>{
            this.MoviePlayer.View.Hidden = false;
            containerView.Add (this.MoviePlayer.View);
            BtnPlayFeedbackUserRespVideo.Hidden = true;
            this.MoviePlayer.Play ();
           });

在 ViewDidLoad 中

public override void ViewDidLoad(){
       // Keyboard popup
            NSNotificationCenter.DefaultCenter.AddObserver
            (UIKeyboard.DidShowNotification,KeyBoardUpNotification);

            // Keyboard Down
            NSNotificationCenter.DefaultCenter.AddObserver
            (UIKeyboard.WillHideNotification,KeyBoardDownNotification);


            MPMoviePlayerController.Notifications.ObservePlaybackDidFinish(HandleMoviePlayerStoppedPlaying);
            MPMoviePlayerController.Notifications.ObserveWillExitFullscreen (HandleDidExitFullScreen);
            MPMoviePlayerController.Notifications.ObserveWillEnterFullscreen(HandleDidEnterFullScreen);

}



    private void HandleDidExitFullScreen(object ss,NSNotificationEventArgs ee){

        IsPlayingFullScreen = false;
        if (this.MoviePlayer != null) {
            this.MoviePlayer.Pause ();
        }
    }


    private void HandleDidEnterFullScreen(object ss,NSNotificationEventArgs ee){


        IsPlayingFullScreen = true;
        if (this.MoviePlayer != null) {
            this.MoviePlayer.Pause ();
        }
    }


    private void HandleMoviePlayerStoppedPlaying(object ss,MPMoviePlayerFinishedEventArgs ee){ //MPMoviePlayerFinishedEventArgs ee){
    if (this.MoviePlayer != null) {

            if (ee.FinishReason == MPMovieFinishReason.PlaybackEnded || ee.FinishReason == MPMovieFinishReason.UserExited || ee.FinishReason == MPMovieFinishReason.PlaybackError) {
                InvokeOnMainThread (() => {
                        if (ReviewState) {
                            if (SelectedLastChallengeForeview != null) {
                                this.MoviePlayer.ContentUrl = NSUrl.FromString (SelectedChallengeForReview.ResponseVideoUrl);
                            } else {
                                if (SelectedChallengeForReview != null) {
                                    this.MoviePlayer.ContentUrl = NSUrl.FromString (SelectedChallengeForReview.ResponseVideoUrl);
                                }
                            }
                        } else {
                            this.MoviePlayer.ContentUrl = NSUrl.FromString(FeedbackToSubmit.ResponseVideoUrl);
                        }

                        this.MoviePlayer.View.Hidden = true;
                        BtnPlayFeedbackUserRespVideo.Hidden = false;
                        this.MoviePlayer.PrepareToPlay();

                });
            }
        }
    }

在ViewWillDisappear View 中

public override void ViewWillDisappear (bool animated)
        {
            base.ViewWillDisappear (animated);

            if (IsPlayingFullScreen) {
                return;
            }


            if (!IsSubmittingFeedback && !ReviewState) {
                if (this.MoviePlayer != null) {
                    this.MoviePlayer.Stop ();

                }


                NSNotificationCenter.DefaultCenter.RemoveObserver (MPMoviePlayerController.WillEnterFullscreenNotification);
                NSNotificationCenter.DefaultCenter.RemoveObserver (MPMoviePlayerController.WillExitFullscreenNotification);
                NSNotificationCenter.DefaultCenter.RemoveObserver (MPMoviePlayerController.PlaybackDidFinishNotification);
                NSNotificationCenter.DefaultCenter.RemoveObserver (UIKeyboard.DidShowNotification);
                NSNotificationCenter.DefaultCenter.RemoveObserver (UIKeyboard.DidHideNotification);



                PopToActivityVC (false);
            }
        }

Answer 1

我知道这有点老了，但不久前遇到了类似的问题。

请记住，当您使用 Ad-Hoc 创建二进制文件时，应用优化设置通常设置为高(默认)。这可能会影响您的应用程序的时间。调高调试方案的优化设置，您应该能够重现该问题。

您的代码看起来没问题。我不擅长 Swift，但翻译它不会出现任何问题。

您还应注意在正确的时间添加和删除通知。这也可能引发您所看到的问题。