当我播放带有视频的视频时，它会在视频的顶部和底部显示黑带，就像URL中的图像一样 https://imgur.com/a/JiUv8rt。我想删除乐队，并以绝对的布局仅显示视频。我如何达到目标？
<pages:PopupPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:d="http://xamarin.com/schemas/2014/forms/design"
xmlns:pages="clr-namespace:Rg.Plugins.Popup.Pages;assembly=Rg.Plugins.Popup"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
xmlns:animations="clr-namespace:Rg.Plugins.Popup.Animations;assembly=Rg.Plugins.Popup"
xmlns:shared="clr-namespace:LibVLCSharp.Forms.Shared;assembly=LibVLCSharp.Forms"
x:Class="App.Pages.WebcamVideoPopUpPage"
BackgroundColor="Transparent">
<pages:PopupPage.Animation>
<animations:ScaleAnimation
PositionIn="Center"
PositionOut="Center"
ScaleIn="1.2"
ScaleOut="0.8"
DurationIn="400"
DurationOut="300"
EasingIn="SinOut"
EasingOut="SinIn"
HasBackgroundAnimation="True"/>
</pages:PopupPage.Animation>
<AbsoluteLayout x:Name="AbsoluteLayoutWebcam"
HorizontalOptions="FillAndExpand"
VerticalOptions="FillAndExpand">
<shared:VideoView x:Name="VideoViewWebcam"
AbsoluteLayout.LayoutFlags="All"
AbsoluteLayout.LayoutBounds="0, 0, 1, 1"
MediaPlayer ="{Binding MediaPlayer}"
MediaPlayerChanged ="VideoView_MediaPlayerChanged"/>
<Label x:Name="DescriptionWebcam"
AbsoluteLayout.LayoutFlags="All"
AbsoluteLayout.LayoutBounds="0, 0, 1, .2"
HorizontalOptions="Fill"
VerticalOptions="Fill"
Text="{Binding InfoWebcam}"
FontSize="Large"
TextColor="White"/>
</AbsoluteLayout>
</pages:PopupPage>
更新 我按照@mtz的建议更新了最新的预发布版本，并按以下方式修改了代码：
public partial class WebcamVideoPopUpPage : PopupPage
{
public WebcamVideoPopUpPage()
{
var vm = App.Locator.WebCamVideoVM;
this.BindingContext = vm;
InitializeComponent();
MediaPlayerWebcam.VideoView.MediaPlayerChanged += VideoView_MediaPlayerChanged;
MediaPlayerWebcam.MediaPlayer.AspectRatio = "FitScreen";
}
protected override void OnAppearing()
{
base.OnAppearing();
Messenger.Default.Send(new OnApperingVideoMessage());
}
private void VideoView_MediaPlayerChanged(object sender, LibVLCSharp.Shared.MediaPlayerChangedEventArgs e)
{
Messenger.Default.Send(new OnVideoViewInitializedMessage());
}
protected override void OnDisappearing()
{
base.OnDisappearing();
MediaPlayerWebcam.MediaPlayer.Stop();
MediaPlayerWebcam.MediaPlayer = null;
}
}
我的xaml：
<AbsoluteLayout x:Name="AbsoluteLayoutWebcam"
HorizontalOptions="FillAndExpand"
VerticalOptions="FillAndExpand">
<shared:MediaPlayerElement x:Name="MediaPlayerWebcam"
AbsoluteLayout.LayoutFlags="All"
AbsoluteLayout.LayoutBounds="0, 0, 1, .4"
MediaPlayer ="{Binding MediaPlayer}"/>
<Label x:Name="DescriptionWebcam"
AbsoluteLayout.LayoutFlags="All"
AbsoluteLayout.LayoutBounds="0, 0, 1, .2"
HorizontalOptions="Fill"
VerticalOptions="Fill"
Text="{Binding InfoWebcam}"
FontSize="Large"
TextColor="White"/>
</AbsoluteLayout>
我的viewModel：
public class WebcamVideoViewModel : BaseViewModel
{
private LibVLC LibVLC { get; set; }
private bool IsLoaded { get; set; }
private bool IsVideoViewInitialized { get; set; }
private Media Media { get; set; }
private MediaPlayer _mediaPlayer;
public MediaPlayer MediaPlayer
{
get { return _mediaPlayer; }
set
{
_mediaPlayer = value;
OnPropertyChanged();
}
}
private string _InfoWebcam { get; set; }
public string InfoWebcam
{
get { return _InfoWebcam; }
set
{
_InfoWebcam = value;
OnPropertyChanged();
}
}
public WebcamVideoViewModel(INavigationService navigationService, IApiAutostradeManagerFactory apiAutostradeFactory) : base(navigationService, apiAutostradeFactory)
{
Messenger.Default.Register<InfoWebcamVideoMessage>(this, OnReceivedInfoWebcam);
Messenger.Default.Register<OnApperingVideoMessage>(this, OnAppearing);
Messenger.Default.Register<OnVideoViewInitializedMessage>(this, OnVideoViewInitialized);
Task.Run(Initialize);
}
private void Initialize()
{
Core.Initialize();
LibVLC = new LibVLC();
MediaPlayer = new MediaPlayer(LibVLC);
}
private async void OnReceivedInfoWebcam(InfoWebcamVideoMessage msg)
{
var response = await ApiManager.GetVideoWebcam(msg.Mpr, msg.Uuid);
if (response.IsSuccessStatusCode)
{
InfoWebcam = msg.T_Description_webcam;
var stream = await response.Content.ReadAsStreamAsync();
Media = new Media(LibVLC, stream);
Play();
}
}
public void OnAppearing(OnApperingVideoMessage msg)
{
IsLoaded = true;
}
public void OnVideoViewInitialized(OnVideoViewInitializedMessage msg)
{
IsVideoViewInitialized = true;
}
private void Play()
{
if (IsLoaded && IsVideoViewInitialized)
{
MediaPlayer.Play(Media);
}
}
}
现在我更接近解决方案了，因为videoView可以通过bootm上的按钮来调整大小，但是我想开始填充AspectRatio，并且我不希望任何期望的视频（换句话说，我d要删除搜索栏并调整视频按钮的大小）。另一个问题是，当我关闭mediaPlayer，然后再次打开一个新视频后，我的应用程序崩溃了。有什么建议吗？
答案 0 :(得分：1)
您需要更改纵横比以“填充屏幕”。
查看操作方法：https://github.com/videolan/libvlcsharp/blob/91b8f06ee1bedd9b3219a4e9ade0a9c44f59fda8/LibVLCSharp.Forms/Shared/PlaybackControls.xaml.cs#L926或使用最新的预发行版LibVLCSharp.Forms程序包，其中包含具有内置此功能的MediaPlayerElement（在稳定版本中很快出现）。
答案 1 :(得分：0)
您要尝试的是拉伸视频。但是请记住，这会影响视频的质量。
为了保持简单，您可以尝试以下经过测试的有效代码：
MediaPlayerWebcam.MediaPlayer.AspectRatio = $"{MediaPlayerWebcam.Width.ToString()}:{MediaPlayerWebcam.Height.ToString()}";
MediaPlayerWebcam.Scale = 0;
答案 2 :(得分：0)
我的场景是全屏播放器，我用这些代码来做的，参考LibVLCSharp.Forms，希望它会有所帮助。代码处理全屏（评论）或用视频填充屏幕。
public void PlayerFullScreen()
{
//restore
if (_isFullScreen)
{
RestoreDefaultWindowInfo();
_isFullScreen = false;
_mediaPlayer.Scale = _originalScale; //reset
_mediaPlayer.AspectRatio = _originalAspectRatio;
//Mouse.Capture(null);
playerBar.Visibility = Visibility.Visible;
}
else // fullscreen(stretch video)
{
this.WindowStyle = WindowStyle.None;
this.ResizeMode = ResizeMode.NoResize;
this.Left = 0;
this.Top = 0;
this.Width = SystemParameters.VirtualScreenWidth;
this.Height = SystemParameters.VirtualScreenHeight;
//this.Topmost = true;
_isFullScreen = true;
_originalScale = _mediaPlayer.Scale; // save original
_originalAspectRatio = _mediaPlayer.AspectRatio;
playerBar.Visibility = Visibility.Collapsed;
MediaTrack? mediaTrack;
try
{
mediaTrack = _mediaPlayer.Media?.Tracks?.FirstOrDefault(x => x.TrackType == TrackType.Video);
}
catch (Exception)
{
mediaTrack = null;
}
if (mediaTrack == null || !mediaTrack.HasValue)
{
return;
}
//get windows scale factor(DPI)
PresentationSource source = PresentationSource.FromVisual(this);
double dpiX=1.0, dpiY=1.0;
if (source != null)
{
dpiX = source.CompositionTarget.TransformToDevice.M11;
dpiY = source.CompositionTarget.TransformToDevice.M22;
}
var displayW = this.Width * dpiX;
var displayH = this.Height * dpiY;
var videoSwapped = mediaTrack.Value.Data.Video.Orientation == VideoOrientation.LeftBottom ||
mediaTrack.Value.Data.Video.Orientation == VideoOrientation.RightTop;
var videoW = mediaTrack.Value.Data.Video.Width;
var videoH = mediaTrack.Value.Data.Video.Height;
if (videoSwapped)
{
var swap = videoW;
videoW = videoH;
videoH = swap;
}
if (mediaTrack.Value.Data.Video.SarNum != mediaTrack.Value.Data.Video.SarDen)
videoW = videoW * mediaTrack.Value.Data.Video.SarNum / mediaTrack.Value.Data.Video.SarDen;
var ar = videoW / (float)videoH;
var dar = displayW / (float)displayH;
float scale;
if (dar >= ar)
scale = (float)displayW / videoW; /* horizontal */
else
scale = (float)displayH / videoH; /* vertical */
//keep ratio of width/height, not fill the srceen
//_mediaPlayer.Scale = scale; // 这是保持视频宽高比的，视频不会变形
//_mediaPlayer.AspectRatio = string.Empty;//这是保持视频宽高比的，视频不会变形
//这是视频变形适配屏幕的情况（满屏）
//fill all the screen by video,video is streched
float xscale, yscale;
xscale = (float)(displayW / videoW);
yscale = (float)(displayH / videoH);
_mediaPlayer.Scale = (xscale<yscale)? xscale:yscale;
string aspectRatio = String.Format("{0}:{1}",
this.Width,this.Height);
_mediaPlayer.AspectRatio = aspectRatio;
}
}