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IPacket Interface

Holds data and is used by objects that implement IDevicePacketStream to transfer data between a device agent application and a desktop computer.

Namespace:  Microsoft.SmartDevice.DeviceAgentTransport
Assembly:  Microsoft.SmartDevice.DeviceAgentTransport (in Microsoft.SmartDevice.DeviceAgentTransport.dll)

Syntax

'Declaration
<GuidAttribute("2F6015CC-2710-4AA1-9408-EAD056B555E1")> _
<InterfaceTypeAttribute(ComInterfaceType.InterfaceIsIUnknown)> _
Public Interface IPacket
'Usage
Dim instance As IPacket
[GuidAttribute("2F6015CC-2710-4AA1-9408-EAD056B555E1")]
[InterfaceTypeAttribute(ComInterfaceType.InterfaceIsIUnknown)]
public interface IPacket
[GuidAttribute(L"2F6015CC-2710-4AA1-9408-EAD056B555E1")]
[InterfaceTypeAttribute(ComInterfaceType::InterfaceIsIUnknown)]
public interface class IPacket
public interface IPacket

Remarks

To get an object that implements this interface, use PacketFactory.GetNewPacket.

Objects that implement IPacket can only hold objects of type byte, byte[], string, int, and char. The interface is not extensible to read and write custom objects. However, users can still transfer custom objects across the stream by either splitting the custom data type into basic data types or serializing the custom data types into a byte array.

Examples

Imports System
Imports System.Collections.Generic
Imports System.Text
Imports Microsoft.SmartDevice.DeviceAgentTransport
Imports System.Windows.Forms


Class Program

    <MTAThread()>  _
    Shared Sub Main(ByVal args() As String) 
        Dim serviceids(0 To 0) As String
        serviceids(0) = "2FAD740C-B5D3-4ad0-BE23-5682503584BF" 

        ' Get an instance of Device Agent Transport 
        Dim transport As IDeviceAgentTransport = _
            DeviceAgentTransportFactory.GetAgentTransport()
        ' Register the callback object with the Device Agent Transport. 
        Dim shutdownCallback As New ShutdownCallback()
        transport.RegisterShutdownCallback(shutdownCallback, shutdownCallback)
        ' Let the desktop application know that this device agent was deployed successfully  
        ' and will handle the supplied list of service IDs.
        transport.AcknowledgeLaunch(Convert.ToUInt32(serviceids.Length), serviceids)

        ' Open a communcation stream with desktop application on the service. 
        Dim packetStream As IDevicePacketStream
        transport.AcceptConnectionEx(serviceids(0), packetStream)
        Dim packet As IPacket

        ' Check for a packet while communication stream is connected. 
        While packetStream.IsConnected()
            ' If a packet is found, display the string and integer data. 
            If packetStream.IsPacketAvailable() Then
                packetStream.Read(packet)
                Dim sb As New StringBuilder()
                While Not packet.IsEndOfPacket()
                    Select Case packet.ReadDataType()
                        Case DataType.BoolType
                            Dim boolValue As Boolean = packet.ReadBool()
                        Case DataType.ByteArrayType
                            ' Read bytes and convert IntPtr to byte[] 
                            Dim ptr As IntPtr
                            Dim size As System.UInt32 = 0
                            packet.ReadBytes(ptr, size)
                            Dim buffer As Byte() = InteropUtils.ConvertIntPtrToByteArray(ptr, _
                                Convert.ToInt32(size))
                        Case DataType.ByteType
                            Dim byteValue As Byte = packet.ReadByte()
                        Case DataType.CharType
                            Dim charValue As Char = packet.ReadChar()
                        Case DataType.Int32Type
                            sb.Append("Int32Type:  " + packet.ReadInt32().ToString() + _
                                      vbCr + vbLf)
                        Case DataType.StringType
                            sb.Append("String:  " + packet.ReadString() + vbCr + vbLf)
                        Case Else 
                    End Select 
                End While
                MessageBox.Show(sb.ToString())
                Exit While 
            End If
            System.Threading.Thread.Sleep(1000)
        End While
        packet = PacketFactory.GetNewPacket()

        ' Write the version of .NET Compact Framework into the packet.
        packet.WriteString("Hello Desktop Computer")
        packet.WriteInt32(Environment.Version.Major)
        packet.WriteInt32(Environment.Version.Minor)
        packet.WriteInt32(Environment.Version.Build)
        packet.WriteInt32(Environment.Version.Revision)

        ' Pass the packet to desktop application.
        packetStream.Write(packet)

    End Sub 'Main
End Class 'Program

' Define your own shutdown implementation 
Class ShutdownCallback
    Implements IAgentTransportShutdownCallback

    Sub Shutdown(ByVal in_pUnknown As Object) _
        Implements IAgentTransportShutdownCallback.Shutdown

        ' Insert cleanup code here 

    End Sub 'Shutdown
End Class 'ShutdownCallback
using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.SmartDevice.DeviceAgentTransport;
using System.Windows.Forms;

class Program
{
    [MTAThread]
    static void Main(string[] args)
    {
        string[] serviceids = { "2FAD740C-B5D3-4ad0-BE23-5682503584BF" };

        // Get an instance of Device Agent Transport
        IDeviceAgentTransport transport = DeviceAgentTransportFactory.GetAgentTransport();

        // Register the callback object with the Device Agent Transport.
        ShutdownCallback shutdownCallback = new ShutdownCallback();
        transport.RegisterShutdownCallback(shutdownCallback, shutdownCallback);

        // Let the desktop application know that this device agent was deployed successfully  
        // and will handle the supplied list of service IDs.
        transport.AcknowledgeLaunch(Convert.ToUInt32(serviceids.Length), serviceids);

        // Open a communcation stream with desktop application on the service.
        IDevicePacketStream packetStream;
        transport.AcceptConnectionEx(serviceids[0], out packetStream);

        IPacket packet;

        // Check for a packet while communication stream is connected. 
        while (packetStream.IsConnected())
        {
            // If a packet is found, display the string and integer data. 
            if (packetStream.IsPacketAvailable())
            {
                packetStream.Read(out packet);
                StringBuilder sb = new StringBuilder();
                while (!packet.IsEndOfPacket())
                {
                    switch (packet.ReadDataType())
                    {
                        case DataType.BoolType:
                            bool boolValue = packet.ReadBool();
                            break;
                        case DataType.ByteArrayType:
                            // Read bytes and convert IntPtr to byte[]
                            IntPtr ptr;
                            uint size = 0;
                            packet.ReadBytes(out ptr, out size);
                            byte[] buffer = InteropUtils.ConvertIntPtrToByteArray(ptr, 
                                Convert.ToInt32(size));
                            break;
                        case DataType.ByteType:
                            byte byteValue = packet.ReadByte();
                            break;
                        case DataType.CharType:
                            char charValue = packet.ReadChar();
                            break;
                        case DataType.Int32Type:
                            sb.Append("Int32Type:  " + packet.ReadInt32().ToString() + "\r\n");
                            break;
                        case DataType.StringType:
                            sb.Append("String:  " + packet.ReadString() + "\r\n");
                            break;
                        default:
                            break;
                    }
                }
                MessageBox.Show(sb.ToString());
                break;
            }
            System.Threading.Thread.Sleep(1000);
        }

        packet = PacketFactory.GetNewPacket();

        // Write the version of .NET Compact Framework into the packet.
        packet.WriteString("Hello Desktop Computer");
        packet.WriteInt32(Environment.Version.Major);
        packet.WriteInt32(Environment.Version.Minor);
        packet.WriteInt32(Environment.Version.Build);
        packet.WriteInt32(Environment.Version.Revision);

        // Pass the packet to desktop application.
        packetStream.Write(packet);
    }
}

// Define your own shutdown implementation 
class ShutdownCallback : IAgentTransportShutdownCallback
{
    public void Shutdown(object in_pUnknown)
    {
        // Insert cleanup code here
    }
}

See Also

Reference

IPacket Members

Microsoft.SmartDevice.DeviceAgentTransport Namespace