Silverlight与WCF之间的通信(6)silverlight+wcf+tcp视频通信[1]单工模式

其实严格来讲，这个实现并非真正意义上的视频通信，既不是P2P的，也没有很高的性能，因为基本上是两个客户端同时往服务器上传递视频信息，然后由服务器进行中转到对方。

重点在于两点

• IIS根目录下放clientaccesspolicy.xml文件
• 注意服务中定义数据量大小2147483646，否则有可能传递不了

这边是单向的客户端定时向服务器传递带聊天标识的数据流：

 

[DataContract] 
    public class UserVideo 
    { 
        [DataMember] 
        public string UserName { get; set; } 
        [DataMember] 
        public string PartnerName { set; get; } 
        [DataMember] 
        public byte[] VideoByte { set; get; } 
    } 

 

 

服务契约只有两个，一个是用来存储视频流，一个是用来提供视频流的

 

[ServiceContract] 
    public interface IChatService 
    { 
        [OperationContract] 
        void SendVideo(UserVideo userVideo); 

        [OperationContract] 
        List<UserVideo> GetVideos(string userName,string partnerName); 
    }

 

 

实现也很简单就是往一个静态的List中添加对象

 

public class ChatService : IChatService 
    { 
        private static List<UserVideo> listVideos = new List<UserVideo>();         

        public void SendVideo(UserVideo userVideo) 
        { 
            listVideos.Add(userVideo); 
        } 

        public List<UserVideo> GetVideos(string userName,string partnerName) 
        { 
            var list = listVideos.Where(m => m.UserName == userName && m.PartnerName == partnerName).ToList(); 
            listVideos.RemoveAll(m => m.PartnerName == partnerName && m.UserName == userName); 
            return list; 
        } 
    }

 

接下来是host方法

 

public class MyHost 
    { 
        static ServiceHost host = null; 
        public static void Open() 
        { 
            host = new ServiceHost(typeof(ChatService)); 
            host.Open(); 
        } 
        public static void Close() 
        { 
            if (host != null && host.State == CommunicationState.Opened) 
            { 
                host.Close(); 
            } 
            host = null; 
        } 
    }

 

最后是启动服务进行监听

 

public class Program 
    { 
        static void Main(string[] args) 
        { 
            MyHost.Open(); 
            System.Console.WriteLine("服务已经启动...   敲任意键停止服务"); 
            System.Console.ReadLine(); 
            MyHost.Close(); 
        } 
    }

 

客户端方法：

开始视频播放

this.btnStartVideo.Click += (o, ev) => 
            { 
                if (source != null) 
                { 
                    source.Stop(); 
                    source.VideoCaptureDevice = CaptureDeviceConfiguration.GetDefaultVideoCaptureDevice(); 
                    VideoBrush vBrush = new VideoBrush(); 
                    vBrush.SetSource(source); 
                    this.rectangleUser.Fill = vBrush; 
                    if (CaptureDeviceConfiguration.AllowedDeviceAccess || CaptureDeviceConfiguration.RequestDeviceAccess()) 
                    { 
                        source.Start(); 
                    } 
                } 
            };

 

向服务器发送数据流

this.btnSendVideo.Click += (o, ev) => 
            { 
                timerForSend = new System.Windows.Threading.DispatcherTimer(); 
                timerForSend.Interval = new TimeSpan(0, 0, 0, 0, 150); 
                timerForSend.Tick += (o1, e1) => { 
                    proxy = new ChatServiceClient(); 
                    WriteableBitmap bmp = new WriteableBitmap(this.rectangleUser, null); 
                    MemoryStream ms = new MemoryStream(); 
                    EncodeJpeg(bmp, ms); 
                    UserVideo userVideo = new UserVideo(); 
                    userVideo.PartnerName = this.Partner; 
                    userVideo.UserName = this.User; 
                    userVideo.VideoByte = ms.GetBuffer(); 
                    proxy.SendVideoCompleted += (o2, e2) => { }; 
                    proxy.SendVideoAsync(userVideo); 
                }; 
                timerForSend.Start(); 
            };

 

从服务期上取得数据流

 

void ReceiveVideo() 
        { 
            timerForReceive = new System.Windows.Threading.DispatcherTimer(); 
            timerForReceive.Interval = new TimeSpan(0, 0, 0, 0, 100); 
            timerForReceive.Tick += (o, e) => { 
                proxy = new ChatServiceClient(); 
                proxy.GetVideosCompleted += (se, ev) => 
                { 
                    if (ev.Error == null) 
                    { 
                        foreach (ChatService.UserVideo video in ev.Result) 
                        { 
                            this.imagePartner.Dispatcher.BeginInvoke(() => { 
                                MemoryStream ms = new MemoryStream(video.VideoByte); 
                                BitmapImage bitmap = new BitmapImage(); 
                                bitmap.SetSource(ms); 
                                imagePartner.Source = bitmap; 
                                ms.Close(); 
                            }); 
                        } 
                    } 
                }; 
                proxy.GetVideosAsync(User, Partner); 
            }; 
            timerForReceive.Start(); 
        }          

 

 

 

单工模式的缺点显而易见，请求--》答复比较耗时，我们下一步将会改造成双工模式的tcp通信。