Socket.IOControl Method

Definition

Namespace:

System.Net.Sockets

Assembly:

System.Net.Sockets.dll

Sets low-level operating modes for the Socket.

Overloads

IOControl(Int32, Byte[], Byte[])	Sets low-level operating modes for the Socket using numerical control codes.
IOControl(IOControlCode, Byte[], Byte[])	Sets low-level operating modes for the Socket using the IOControlCode enumeration to specify control codes.

IOControl(Int32, Byte[], Byte[])

Source:

Socket.cs

Sets low-level operating modes for the Socket using numerical control codes.

public:
 int IOControl(int ioControlCode, cli::array <System::Byte> ^ optionInValue, cli::array <System::Byte> ^ optionOutValue);

public int IOControl (int ioControlCode, byte[]? optionInValue, byte[]? optionOutValue);

member this.IOControl : int * byte[] * byte[] -> int

Public Function IOControl (ioControlCode As Integer, optionInValue As Byte(), optionOutValue As Byte()) As Integer

Parameters

ioControlCode

Int32

An Int32 value that specifies the control code of the operation to perform.

optionInValue

Byte[]

A Byte array that contains the input data required by the operation.

optionOutValue

Byte[]

A Byte array that contains the output data returned by the operation.

Returns

Int32

The number of bytes in the optionOutValue parameter.

Exceptions

SocketException

An error occurred when attempting to access the socket.

ObjectDisposedException

The Socket has been closed.

InvalidOperationException

An attempt was made to change the blocking mode without using the Blocking property.

SecurityException

A caller in the call stack does not have the required permissions.

Examples

The following code example compares the results of FIONREAD and the Available property.

// FIONREAD is also available as the "Available" property.
const int FIONREAD = 0x4004667F;

void DisplayPendingByteCount( Socket^ s )
{
   array<Byte>^ outValue = BitConverter::GetBytes( 0 );
   
   // Check how many bytes have been received.
   s->IOControl( FIONREAD, nullptr, outValue );

   UInt32 bytesAvailable = BitConverter::ToUInt32( outValue, 0 );
   Console::WriteLine( "server has {0} bytes pending. Available property says {1}.",
      bytesAvailable, s->Available );

   return;
}

 // FIONREAD is also available as the "Available" property.
public const int FIONREAD   = 0x4004667F;

static void DisplayPendingByteCount(Socket s)
 {
     byte[] outValue = BitConverter.GetBytes(0);

     // Check how many bytes have been received.
     s.IOControl(FIONREAD, null, outValue);

     uint bytesAvailable = BitConverter.ToUInt32(outValue, 0);
     Console.WriteLine("server has {0} bytes pending. Available property says {1}.",
         bytesAvailable, s.Available);

     return;
 }

Remarks

The IOControl method provides low-level access to the operating system Socket underlying the current instance of the Socket class. For more information, see the WSAIoctl documentation.

Note

If you receive a SocketException, use the SocketException.ErrorCode property to obtain the specific error code. After you have obtained this code, refer to the Windows Sockets version 2 API error code documentation for a detailed description of the error.

Note

This member outputs trace information when you enable network tracing in your application. For more information, see Network Tracing in .NET Framework.

IOControl(IOControlCode, Byte[], Byte[])

Source:

Socket.cs

Sets low-level operating modes for the Socket using the IOControlCode enumeration to specify control codes.

public:
 int IOControl(System::Net::Sockets::IOControlCode ioControlCode, cli::array <System::Byte> ^ optionInValue, cli::array <System::Byte> ^ optionOutValue);

public int IOControl (System.Net.Sockets.IOControlCode ioControlCode, byte[]? optionInValue, byte[]? optionOutValue);

member this.IOControl : System.Net.Sockets.IOControlCode * byte[] * byte[] -> int

Public Function IOControl (ioControlCode As IOControlCode, optionInValue As Byte(), optionOutValue As Byte()) As Integer

Parameters

ioControlCode

IOControlCode

A IOControlCode value that specifies the control code of the operation to perform.

optionInValue

Byte[]

An array of type Byte that contains the input data required by the operation.

optionOutValue

Byte[]

An array of type Byte that contains the output data returned by the operation.

Returns

Int32

The number of bytes in the optionOutValue parameter.

Exceptions

SocketException

An error occurred when attempting to access the socket.

ObjectDisposedException

The Socket has been closed.

InvalidOperationException

An attempt was made to change the blocking mode without using the Blocking property.

Examples

The following code example compares the results of calling IOControl with DataToRead and the Available property.

void DisplayPendingByteCount( Socket^ s )
{
   array<Byte>^ outValue = BitConverter::GetBytes( 0 );
   
   // Check how many bytes have been received.
   s->IOControl( IOControlCode::DataToRead, nullptr, outValue );

   UInt32 bytesAvailable = BitConverter::ToUInt32( outValue, 0 );
   Console::Write( "server has {0} bytes pending,",
      bytesAvailable );
   Console::WriteLine( "Available property says {1}.",
      s->Available );
   return;
}

static void DisplayPendingByteCount(Socket s)
{
    byte[] outValue = BitConverter.GetBytes(0);

    // Check how many bytes have been received.
    s.IOControl(IOControlCode.DataToRead, null, outValue);

    uint bytesAvailable = BitConverter.ToUInt32(outValue, 0);
    Console.Write("server has {0} bytes pending. ",
        bytesAvailable);
    Console.WriteLine("Available property says {1}.",
                     s.Available);

    return;
}

Remarks

This method provides low-level access to the operating system Socket underlying the current instance of the Socket class. For more, see the WSAIoctl documentation.

Note

If you receive a SocketException, use the SocketException.ErrorCode property to obtain the specific error code. After you have obtained this code, refer to the Windows Sockets version 2 API error code documentation for a detailed description of the error.

Note

This member outputs trace information when you enable network tracing in your application. For more information, see Network Tracing in .NET Framework.