WriteMessage Method

Summary

Sends a text message to all connected clients.

Syntax
C#
VB
C++
[DispIdAttribute(4)] 
void WriteMessage(  
   string Message 
) 
  
<DispIdAttribute(4)> 
Sub WriteMessage( _ 
   ByVal Message As String _ 
)  
[DispIdAttribute(4)] 
void WriteMessage(  
   String^ Message 
)  

Parameters

Message
A System.String containing the message to send to all connected clients.

Remarks

On the client side, the message can be received using ReadMessage.

Example
C#
VB
using Leadtools; 
using Leadtools.Multimedia; 
using LeadtoolsMultimediaExamples.Fixtures; 
 
public bool _result = false; 
public CaptureAndPlayCtrlForm _serverAndClient = new CaptureAndPlayCtrlForm(); 
 
bool _msgSent = false; 
CaptureCtrl _captureCtrl; 
PlayCtrl _playCtrl; 
LMNetMux _pMux; 
LMNetDmx _pDemux; 
 
const string _networkUrl = @"ltsf://127.0.0.1:27015"; // network stream url 
const string TestMessage = "LEAD NETWORK"; 
 
public void WriteMessageExample() 
{ 
   // reference the capture control 
   _captureCtrl = _serverAndClient.CaptureCtrl; 
 
   // reference the play control 
   _playCtrl = _serverAndClient.PlayCtrl; 
 
   try 
   { 
      // try to find a video camera 
      if (_captureCtrl.VideoDevices["Logitech"] == null) 
         throw new Exception("No Logitech video device available"); 
 
      _captureCtrl.VideoDevices["Logitech"].Selected = true; 
 
      // select a video compressor 
      _captureCtrl.VideoCompressors.Mpeg4.Selected = true; 
 
      // set the target output file 
      _captureCtrl.TargetFormat = TargetFormatType.NET; 
      _captureCtrl.TargetFile = _networkUrl; 
 
      if (_captureCtrl.IsModeAvailable(CaptureMode.Video)) 
      { 
         // just 10 seconds of capture time 
         _captureCtrl.TimeLimit = 10; 
         _captureCtrl.UseTimeLimit = true; 
 
         _captureCtrl.Preview = true; 
 
         // subscribe to the started and progress events for this example 
         // we will connect a client after the capture starts 
         // and send a test message after 5 seconds. 
         _captureCtrl.Started += new EventHandler(CaptureCtrl_Started); 
         _captureCtrl.Progress += new ProgressEventHandler(CaptureCtrl_Progress); 
 
         // ready the capture graph in order to get the LNMetMux instance 
         _captureCtrl.ReadyCapture(CaptureMode.Video); 
 
         // get the network multiplexer reference 
         _pMux = _captureCtrl.GetSubObject(CaptureObject.TargetFilter) as LMNetMux; 
 
         if (_pMux != null) 
         { 
            // set some mux settings 
            _pMux.LiveSource = true; 
         } 
 
         // start capture 
         _captureCtrl.StartCapture(CaptureMode.Video); 
 
         // we'll loop on the state and pump messages for this example. 
         // but you should not need to if running from a Windows Forms application. 
         while (_captureCtrl.State == CaptureState.Running 
               || _playCtrl.State == PlayState.Running) 
         { 
            Application.DoEvents(); 
         } 
 
         // release the mux and demux COM objects 
         if (_pMux != null) 
            Marshal.ReleaseComObject(_pMux); 
 
         if (_pDemux != null) 
            Marshal.ReleaseComObject(_pDemux); 
      } 
   } 
   catch (Exception) 
   { 
      _result = false; 
   } 
} 
 
void CaptureCtrl_Progress(object sender, ProgressEventArgs e) 
{ 
   // for this test we will send a message after  
   // 5 secs of capture time 
   if (e.time > 5000 && !_msgSent) 
   { 
      _pMux.WriteMessage(TestMessage); 
      Console.WriteLine("Server sent message"); 
      _msgSent = true; 
   } 
} 
 
void CaptureCtrl_Started(object sender, EventArgs e) 
{ 
   StartClient(); 
} 
 
private void StartClient() 
{ 
   _playCtrl.SourceFile = _networkUrl; 
   _pDemux = _playCtrl.GetSubObject(PlayObject.Splitter) as LMNetDmx; 
 
   _serverAndClient.TestTimer.Interval = 100; 
   _serverAndClient.TestTimer.Tick += new EventHandler(PlayTimer_Tick); 
   _serverAndClient.TestTimer.Start(); 
} 
 
void PlayTimer_Tick(object sender, EventArgs e) 
{ 
   _serverAndClient.TestTimer.Enabled = false; 
   if (_pDemux != null) 
   { 
      string msg = _pDemux.ReadMessage(); 
 
      // set the result to what we expect 
      if (msg == TestMessage) 
      { 
         _result = true; 
         Console.WriteLine("Client received message"); 
      } 
   } 
   _serverAndClient.TestTimer.Enabled = true; 
} 
Imports Leadtools 
Imports Leadtools.Multimedia 
Imports LeadtoolsMultimediaExamples.Fixtures 
 
Public _result As Boolean = False 
Public _serverAndClient As CaptureAndPlayCtrlForm = New CaptureAndPlayCtrlForm() 
 
Private _msgSent As Boolean = False 
Private _captureCtrl As CaptureCtrl 
Private _playCtrl As PlayCtrl 
Private _pMux As LMNetMux 
Private _pDemux As LMNetDmx 
 
Private Const _networkUrl As String = "ltsf://127.0.0.1:27015" ' network stream url 
Private Const TestMessage As String = "LEAD NETWORK" 
 
Public Sub WriteMessageExample() 
   ' reference the capture control 
   _captureCtrl = _serverAndClient.CaptureCtrl 
 
   ' reference the play control 
   _playCtrl = _serverAndClient.PlayCtrl 
 
   Try 
      ' try to find a video camera 
      If _captureCtrl.VideoDevices("Logitech") Is Nothing Then 
         Throw New Exception("No Logitech video device available") 
      End If 
 
      _captureCtrl.VideoDevices("Logitech").Selected = True 
 
      ' select a video compressor 
      _captureCtrl.VideoCompressors.Mpeg4.Selected = True 
 
      ' set the target output file 
      _captureCtrl.TargetFormat = TargetFormatType.NET 
      _captureCtrl.TargetFile = _networkUrl 
 
      If _captureCtrl.IsModeAvailable(CaptureMode.Video) Then 
         ' just 10 seconds of capture time 
         _captureCtrl.TimeLimit = 10 
         _captureCtrl.UseTimeLimit = True 
 
         _captureCtrl.Preview = True 
 
         ' subscribe to the started and progress events for this example 
         ' we will connect a client after the capture starts 
         ' and send a test message after 5 seconds. 
         AddHandler _captureCtrl.Started, AddressOf CaptureCtrl_Started 
         AddHandler _captureCtrl.Progress, AddressOf CaptureCtrl_Progress 
 
         ' ready the capture graph in order to get the LNMetMux instance 
         _captureCtrl.ReadyCapture(CaptureMode.Video) 
 
         ' get the network multiplexer reference 
         _pMux = TryCast(_captureCtrl.GetSubObject(CaptureObject.TargetFilter), LMNetMux) 
 
         If Not _pMux Is Nothing Then 
            ' set some mux settings 
            _pMux.LiveSource = True 
         End If 
 
         ' start capture 
         _captureCtrl.StartCapture(CaptureMode.Video) 
 
         ' we'll loop on the state and pump messages for this example. 
         ' but you should not need to if running from a Windows Forms application. 
         Do While _captureCtrl.State = CaptureState.Running OrElse _playCtrl.State = PlayState.Running 
            Application.DoEvents() 
         Loop 
 
         ' release the mux and demux COM objects 
         If Not _pMux Is Nothing Then 
            Marshal.ReleaseComObject(_pMux) 
         End If 
 
         If Not _pDemux Is Nothing Then 
            Marshal.ReleaseComObject(_pDemux) 
         End If 
      End If 
   Catch e1 As Exception 
      _result = False 
   End Try 
End Sub 
 
Private Sub CaptureCtrl_Progress(ByVal sender As Object, ByVal e As ProgressEventArgs) 
   ' for this test we will send a message after  
   ' 5 secs of capture time 
   If e.time > 5000 AndAlso (Not _msgSent) Then 
      _pMux.WriteMessage(TestMessage) 
      Console.WriteLine("Server sent message") 
      _msgSent = True 
   End If 
End Sub 
 
Private Sub CaptureCtrl_Started(ByVal sender As Object, ByVal e As EventArgs) 
   StartClient() 
End Sub 
 
Private Sub StartClient() 
   _playCtrl.SourceFile = _networkUrl 
   _pDemux = TryCast(_playCtrl.GetSubObject(PlayObject.Splitter), LMNetDmx) 
 
   _serverAndClient.TestTimer.Interval = 100 
   AddHandler _serverAndClient.TestTimer.Tick, AddressOf PlayTimer_Tick 
   _serverAndClient.TestTimer.Start() 
End Sub 
 
Private Sub PlayTimer_Tick(ByVal sender As Object, ByVal e As EventArgs) 
   _serverAndClient.TestTimer.Enabled = False 
   If Not _pDemux Is Nothing Then 
      Dim msg As String = _pDemux.ReadMessage() 
 
      ' set the result to what we expect 
      If msg = TestMessage Then 
         _result = True 
         Console.WriteLine("Client received message") 
      End If 
   End If 
   _serverAndClient.TestTimer.Enabled = True 
End Sub 

Requirements

Target Platforms

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