WPF媒体播放器（MediaElement）打开指定的视频、播放、暂停、快进、快退、截图

XAML

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 System.IO;
using System.Runtime.InteropServices;
using System.Windows.Threading;
using System.Windows.Controls.Primitives;

namespace MediaSampleWPF
{
    public partial class Window1 : Window
    {
        DispatcherTimer timer;

        #region Constructor
        public Window1()
        {
            InitializeComponent();
            IsPlaying(false);
            timer = new DispatcherTimer();
            timer.Interval = TimeSpan.FromMilliseconds(10);
            timer.Tick += new EventHandler(timer_Tick);
        }
        #endregion

        #region IsPlaying(bool)
        private void IsPlaying(bool bValue)
        {
            btnStop.IsEnabled = bValue;
            btnMoveBackward.IsEnabled = bValue;
            btnMoveForward.IsEnabled = bValue;
            btnPlay.IsEnabled = bValue;
            btnScreenShot.IsEnabled = bValue;
            seekBar.IsEnabled = bValue;
        }
        #endregion

        #region Play and Pause
        private void btnPlay_Click(object sender, RoutedEventArgs e)
        {
            IsPlaying(true);
            if (btnPlay.Content.ToString() == "播放")
            {
                MediaEL.Play();
                btnPlay.Content = "暂停";
            }
            else
            {
                MediaEL.Pause();
                btnPlay.Content = "播放";
            }
        }
        #endregion

        #region Stop
        private void btnStop_Click(object sender, RoutedEventArgs e)
        {
            MediaEL.Stop();
            btnPlay.Content = "播放";
            IsPlaying(false);
            btnPlay.IsEnabled = true;
        }
        #endregion

        #region Back and Forward
        private void btnMoveForward_Click(object sender, RoutedEventArgs e)
        {
            MediaEL.Position = MediaEL.Position + TimeSpan.FromSeconds(10);
        }

        private void btnMoveBackward_Click(object sender, RoutedEventArgs e)
        {
            MediaEL.Position = MediaEL.Position - TimeSpan.FromSeconds(10);
        }
        #endregion

        #region Open Media
        private void btnOpen_Click(object sender, RoutedEventArgs e)
        {
            System.Windows.Forms.OpenFileDialog ofd = new System.Windows.Forms.OpenFileDialog();
            ofd.Filter = "Video Files (*.wmv)|*.wmv";
            if (ofd.ShowDialog() == System.Windows.Forms.DialogResult.OK)
            {
                MediaEL.Source = new Uri(ofd.FileName);
                btnPlay.IsEnabled = true;
            }
        }
        #endregion

        #region Capture Screenshot
        private void btnScreenShot_Click(object sender, RoutedEventArgs e)
        {
            byte[] screenshot = MediaEL.GetScreenShot(1, 90);
            FileStream fileStream = new FileStream(@"Capture.jpg", FileMode.Create, FileAccess.ReadWrite);
            BinaryWriter binaryWriter = new BinaryWriter(fileStream);
            binaryWriter.Write(screenshot);
            binaryWriter.Close();
        }
        #endregion

        #region Seek Bar
        private void MediaEL_MediaOpened(object sender, RoutedEventArgs e)
        {
            if (MediaEL.NaturalDuration.HasTimeSpan)
            {
                TimeSpan ts = MediaEL.NaturalDuration.TimeSpan;
                seekBar.Maximum = ts.TotalSeconds;
                seekBar.SmallChange = 1;
                seekBar.LargeChange = Math.Min(10, ts.Seconds / 10);
            }
            timer.Start();
        }

bool isDragging = false;

        void timer_Tick(object sender, EventArgs e)
        {
            if (!isDragging)
            {
                seekBar.Value = MediaEL.Position.TotalSeconds;
            }
        }

        private void seekBar_DragStarted(object sender, DragStartedEventArgs e)
        {
            isDragging = true;
        }

        private void seekBar_DragCompleted(object sender, DragCompletedEventArgs e)
        {
            isDragging = false;
            MediaEL.Position = TimeSpan.FromSeconds(seekBar.Value);
        }
        #endregion

        #region MediaEnd
        private void MediaEL_MediaEnded(object sender, RoutedEventArgs e)
        {
            MediaEL.Stop();
            btnPlay.Content = "播放";
        }
        #endregion
    }

    #region Extension Methods
    public static class ScreenShot
    {
        public static byte[] GetScreenShot(this UIElement source, double scale, int quality)
        {
            double actualHeight = source.RenderSize.Height;
            double actualWidth = source.RenderSize.Width;
            double renderHeight = actualHeight * scale;
            double renderWidth = actualWidth * scale;

            RenderTargetBitmap renderTarget = new RenderTargetBitmap((int)renderWidth,
                (int)renderHeight, 96, 96, PixelFormats.Pbgra32);
            VisualBrush sourceBrush = new VisualBrush(source);

DrawingVisual drawingVisual = new DrawingVisual();
DrawingContext drawingContext = drawingVisual.RenderOpen();

            using (drawingContext)
            {
                drawingContext.PushTransform(new ScaleTransform(scale, scale));
                drawingContext.DrawRectangle(sourceBrush, null, new Rect(new Point(0, 0),
                    new Point(actualWidth, actualHeight)));
            }
            renderTarget.Render(drawingVisual);

            JpegBitmapEncoder jpgEncoder = new JpegBitmapEncoder();
            jpgEncoder.QualityLevel = quality;
            jpgEncoder.Frames.Add(BitmapFrame.Create(renderTarget));

Byte[] imageArray;

            using (MemoryStream outputStream = new MemoryStream())
            {
                jpgEncoder.Save(outputStream);
                imageArray = outputStream.ToArray();
            }
            return imageArray;
        }
    }
    #endregion
}

你可以到http://www.wpf100.com/html/5/2012-03/article-167.html下载源码

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WPF媒体播放器（MediaElement）打开指定的视频、播放、暂停、快进、快退、截图

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