WPF MediaElement播放器2

在此问个问题，MediaElement播放本地和http上的视频没问题，但是ftp的怎么在本例中播放不了

若高手了解，请不吝赐教

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Windows;

using System.Windows.Controls;

using System.Windows.Data;

using System.Windows.Documents;

using System.Windows.Input;

using System.Windows.Media;

using System.Windows.Media.Imaging;

using System.Windows.Navigation;

using System.Windows.Shapes;

using Microsoft.Win32;

using System.IO;

using System.Windows.Threading;

using System.Threading;

using System.Data;

using System.Windows.Forms;



namespace MediaPlayer_Beta

{

    /// <summary>

    /// Interaction logic for MainWindow.xaml

    /// </summary>

    public partial class MainWindow : Window

    {



        DispatcherTimer timer;



        public delegate void timerTick();

        timerTick tick;



        bool isDragging = false;

        bool fileIsPlaying = false;

        string sec, min, hours;



        public MainWindow()

        {

            this.Left = 0;

            this.Top = 0;

            InitializeComponent();

            seekSlider.Width = SystemParameters.MaximizedPrimaryScreenWidth - 150;

            this.WindowState = System.Windows.WindowState.Maximized;

            timer = new DispatcherTimer();

            timer.Interval = TimeSpan.FromSeconds(1);

            timer.Tick += new EventHandler(timer_Tick);

            tick = new timerTick(changeStatus);

        }



        void timer_Tick(object sender, EventArgs e)

        {

            Dispatcher.Invoke(tick);

        }





        //visualize progressBar 

        void changeStatus()

        {

            if (fileIsPlaying)

            {



                #region customizeTime

                if (mediaElement.Position.Seconds < 10)

                    sec = "0" + mediaElement.Position.Seconds.ToString();

                else

                    sec = mediaElement.Position.Seconds.ToString();





                if (mediaElement.Position.Minutes < 10)

                    min = "0" + mediaElement.Position.Minutes.ToString();

                else

                    min = mediaElement.Position.Minutes.ToString();



                if (mediaElement.Position.Hours < 10)

                    hours = "0" + mediaElement.Position.Hours.ToString();

                else

                    hours = mediaElement.Position.Hours.ToString();



                #endregion customizeTime



                seekSlider.Value = mediaElement.Position.TotalMilliseconds;

                progressBar.Value = mediaElement.Position.TotalMilliseconds;



                if (mediaElement.Position.Hours == 0)

                {



                    currentTimeTextBlock.Text = min + ":" + sec;

                }

                else

                {

                    currentTimeTextBlock.Text = hours + ":" + min + ":" + sec;

                }

            }

        }





        //open the file

        private void openFileButton_Click(object sender, RoutedEventArgs e)

        {

            string FileName = "http://mschannel9.vo.msecnd.net/o9/mix/09/wmv/key01.wmv";

            //"ftp://test:[email protected]/media/Linux.wmv";//Ftp测试不能播放，需下载本地再打开

            //"e:\\text\\dian\\media\\test.avi";

            mediaElement.Source = new Uri(FileName);

            Thread.Sleep(50);

            mediaElement.Close();

            mediaElement.Play();

        }





        //occurs when the file is opened

        public void mediaElement_MediaOpened(object sender, RoutedEventArgs e)

        {

            timer.Start();

            fileIsPlaying = true;

            openMedia();

        }





        //opens media,adds file to playlist and gets file info

        public void openMedia()

        {

            InitializePropertyValues();

            try

            {

                #region customizeTime

                if (mediaElement.NaturalDuration.TimeSpan.Seconds < 10)

                    sec = "0" + mediaElement.Position.Seconds.ToString();

                else

                    sec = mediaElement.NaturalDuration.TimeSpan.Seconds.ToString();



                if (mediaElement.NaturalDuration.TimeSpan.Minutes < 10)

                    min = "0" + mediaElement.NaturalDuration.TimeSpan.Minutes.ToString();

                else

                    min = mediaElement.NaturalDuration.TimeSpan.Minutes.ToString();



                if (mediaElement.NaturalDuration.TimeSpan.Hours < 10)

                    hours = "0" + mediaElement.NaturalDuration.TimeSpan.Hours.ToString();

                else

                    hours = mediaElement.NaturalDuration.TimeSpan.Hours.ToString();



                if (mediaElement.NaturalDuration.TimeSpan.Hours == 0)

                {



                    endTimeTextBlock.Text = min + ":" + sec;

                }

                else

                {

                    endTimeTextBlock.Text = hours + ":" + min + ":" + sec;

                }



                #endregion customizeTime

            }

            catch { }

            string path = mediaElement.Source.LocalPath.ToString();



            double duration = mediaElement.NaturalDuration.TimeSpan.TotalMilliseconds;

            seekSlider.Maximum = duration;

            progressBar.Maximum = duration;



            mediaElement.Volume = volumeSlider.Value;

            mediaElement.SpeedRatio = speedRatioSlider.Value + 1;

            mediaElement.ScrubbingEnabled = true;



            volumeSlider.ValueChanged += new RoutedPropertyChangedEventHandler<double>(volumeSlider_ValueChanged);

            speedRatioSlider.ValueChanged += new RoutedPropertyChangedEventHandler<double>(speedRatioSlider_ValueChanged);

        }



        //occurs when the file is done playing

        private void mediaElement_MediaEnded(object sender, RoutedEventArgs e)

        {

            mediaElement.Stop();

            volumeSlider.ValueChanged -= new RoutedPropertyChangedEventHandler<double>(volumeSlider_ValueChanged);

            speedRatioSlider.ValueChanged -= new RoutedPropertyChangedEventHandler<double>(speedRatioSlider_ValueChanged);

        }





        //initialize properties of file

        void InitializePropertyValues()

        {

            mediaElement.Volume = (double)volumeSlider.Value;

            mediaElement.SpeedRatio = (double)speedRatioSlider.Value + 1;

        }





        //seek to desirable position of the file

        private void seekSlider_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)

        {

            TimeSpan ts = new TimeSpan(0, 0, 0, 0, (int)seekSlider.Value);



            changePostion(ts);

        }





        //mouse down on slide bar in order to seek

        private void seekSlider_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)

        {

            isDragging = true;

            fileIsPlaying = false;

        }





        private void seekSlider_PreviewMouseLeftButtonUp(object sender, MouseButtonEventArgs e)

        {

            if (isDragging)

            {

                TimeSpan ts = new TimeSpan(0, 0, 0, 0, (int)seekSlider.Value);

                changePostion(ts);

                fileIsPlaying = true;

            }

            isDragging = false;

        }





        //change position of the file

        void changePostion(TimeSpan ts)

        {

            mediaElement.Position = ts;

        }





        //change the speed of the playback

        void speedRatioSlider_ValueChanged(object sender, RoutedPropertyChangedEventArgs<double> e)

        {

            mediaElement.SpeedRatio = speedRatioSlider.Value + 1;

            speedTextBlock.Text = speedRatioSlider.Value + "x";

        }



        //play the file

        private void playButton__Click(object sender, RoutedEventArgs e)

        {

            fileIsPlaying = true;

            mediaElement.Play();

            timer.Start();

        }





        //pause the file

        private void pauseButton_Click(object sender, RoutedEventArgs e)

        {

            fileIsPlaying = false;

            mediaElement.Pause();

            timer.Stop();

        }





        //stop the file

        private void stopButton_Click(object sender, RoutedEventArgs e)

        {

            fileIsPlaying = false;

            timer.Stop();

            mediaElement.Stop();

            seekSlider.Value = 0;

            progressBar.Value = 0;

            currentTimeTextBlock.Text = "00:00";

        }





        //turn volume up-down

        private void volumeSlider_ValueChanged(object sender, RoutedPropertyChangedEventArgs<double> e)

        {

            mediaElement.Volume = volumeSlider.Value;

        }



    }

}

<Window

        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"

        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"

        mc:Ignorable="d"

        x:Class="MediaPlayer_Beta.MainWindow"

        IsHitTestVisible="True" Background="#00000000" ResizeMode="CanResize" IsTabStop="True" 

        Grid.IsSharedSizeScope="True" UseLayoutRounding="True" HorizontalContentAlignment="Center" 

        WindowStyle="ThreeDBorderWindow" AllowsTransparency="False" d:DesignHeight="385" d:DesignWidth="585">

    <Grid  x:Name="mainGrid" Background="#FF0A0A0A" Height="{Binding}">

        <Grid.RowDefinitions>

            <RowDefinition Height="286*" />

            <RowDefinition Height="23" />

            <RowDefinition Height="30" />

        </Grid.RowDefinitions>

        <MediaElement MediaEnded="mediaElement_MediaEnded" MediaOpened="mediaElement_MediaOpened" LoadedBehavior="Manual" HorizontalAlignment="Right" Name="mediaElement" VerticalAlignment="Bottom" Opacity="1" AllowDrop="True" Stretch="Fill" IsMuted="False" />

        <Button Content="打开" Height="30" HorizontalAlignment="Left" Margin="220,0,0,0" Name="openFileButton" VerticalAlignment="Top" Width="66" Click="openFileButton_Click" Background="#FF030303" Foreground="#FFE8E8E8" Grid.Row="2" />

        <Button x:Name="stopButton" Content="停止" Margin="149,0,0,0" Click="stopButton_Click" Background="#FF030303" Foreground="#FFE8E8E8" HorizontalAlignment="Left" Width="65" Grid.Row="2" />

        <Slider Height="30" HorizontalAlignment="Left" Margin="292,0,0,0" Name="volumeSlider" VerticalAlignment="Top" Width="87" Value="0.5" Maximum="1" SmallChange="0.01" LargeChange="0.1" Background="Black" Foreground="#FFDBDBDB" IsMoveToPointEnabled="True" Grid.Row="2"></Slider>

        <Slider Name="speedRatioSlider" VerticalAlignment="Center" Value="0" Width="70" Margin="385,0,0,0" Maximum="3" SmallChange="1" Background="Black" UseLayoutRounding="True" TickPlacement="BottomRight" Foreground="#FFDBDBDB" Height="30" Grid.Row="2" HorizontalAlignment="Left"></Slider>

        <Button x:Name="pauseButton" Content="暂停" Margin="71,0,0,0" Click="pauseButton_Click" Background="#FF030303" Foreground="#FFE8E8E8" Width="76" HorizontalAlignment="Left" Grid.Row="2" />

        <Button x:Name="playButton_" Content="播放" HorizontalAlignment="Left" Width="65" Click="playButton__Click" ClipToBounds="True" Background="#FF030303" Foreground="#FFE8E8E8" Grid.Row="2" Margin="4,0,0,0" />

        <TextBlock Height="23" Name="endTimeTextBlock" Text="00:00" Width="68" Background="{x:Null}" Foreground="White" VerticalAlignment="Center" HorizontalAlignment="Right" Margin="495,0,0,0" FlowDirection="RightToLeft" Grid.Row="1" TextAlignment="Center"></TextBlock>

        <TextBlock Height="23" Name="currentTimeTextBlock" Text="00:00" Width="68" Background="Black" Foreground="#FFDBDBDB" TextAlignment="Center" HorizontalAlignment="Left" VerticalAlignment="Center" Margin="4,0,0,0" Grid.Row="1"></TextBlock>

        <Slider Width="{Binding}" PreviewMouseLeftButtonUp="seekSlider_PreviewMouseLeftButtonUp" PreviewMouseLeftButtonDown="seekSlider_PreviewMouseLeftButtonDown" MouseLeftButtonUp="seekSlider_MouseLeftButtonUp" Name="seekSlider" Background="{x:Null}" Foreground="Red" BorderBrush="{x:Null}" IsMoveToPointEnabled="True" TickPlacement="None" SnapsToDevicePixels="False" OpacityMask="{x:Null}" IsManipulationEnabled="True" IsSnapToTickEnabled="False" IsSelectionRangeEnabled="False" IsTabStop="False" AutoToolTipPlacement="None" AllowDrop="False" Height="23" VerticalAlignment="Center" VerticalContentAlignment="Center" HorizontalContentAlignment="Center" HorizontalAlignment="Center" Grid.Row="1"  Margin="68,0,68,0"></Slider>

        <ProgressBar Height="6" Name="progressBar" Background="#00000000" BorderBrush="Black" VerticalContentAlignment="Center" HorizontalContentAlignment="Center" Margin="68,0,68,0" Grid.Row="1" IsHitTestVisible="False" BorderThickness="0" Foreground="#FF0089FF"></ProgressBar>

        <TextBlock Height="24" Name="speedTextBlock" Text="0x" Width="34" Background="{x:Null}" Foreground="White" VerticalAlignment="Center" HorizontalAlignment="Left" Margin="460,7,0,0" FlowDirection="RightToLeft" Grid.Row="2" TextAlignment="Right"></TextBlock>

    </Grid>

</Window>