Articolo
11/18/2011

UdpAnySourceMulticastClient.BeginSendTo Method

Microsoft Silverlight will reach end of support after October 2021. Learn more.

Begins the operation of sending a unicast packet to the specified destination.

Namespace: System.Net.Sockets
Assembly: System.Net (in System.Net.dll)

Syntax

'Declaration
<SecuritySafeCriticalAttribute> _
Public Function BeginSendTo ( _
    buffer As Byte(), _
    offset As Integer, _
    count As Integer, _
    remoteEndPoint As IPEndPoint, _
    callback As AsyncCallback, _
    state As Object _
) As IAsyncResult

[SecuritySafeCriticalAttribute]
public IAsyncResult BeginSendTo(
    byte[] buffer,
    int offset,
    int count,
    IPEndPoint remoteEndPoint,
    AsyncCallback callback,
    Object state
)

Parameters

buffer
Type: array<System.Byte[]
The buffer that contains the data to send.

offset
Type: System.Int32
The offset, in bytes, from the beginning of the buffer to read the data to be sent.

count
Type: System.Int32
The number of bytes to send from the buffer.

remoteEndPoint
Type: System.Net.IPEndPoint
The remote endpoint to which the packet is to be sent.

callback
Type: System.AsyncCallback
The callback method to invoke when the operation completes.

state
Type: System.Object
Optional state information to pass to the callback method for this operation.

Return Value

Type: System.IAsyncResult
An IAsyncResult that references this operation.

Exceptions

Exception	Condition
ArgumentNullException	buffer is nulla null reference (Nothing in Visual Basic).
ArgumentOutOfRangeException	offset is less than 0 -or- offset is greater than the length of the buffer. -or- count is less than 0 -or- offset plus the count is greater than the length of the buffer.
InvalidOperationException	The multicast group has not yet been joined.
ObjectDisposedException	The UdpAnySourceMulticastClient has been disposed.
SocketException	An error occurred when attempting to access the socket for sending. See the Remarks section for more information.

Remarks

The BeginSendTo method begins an operation of sending a UDP packet to the joined multicast group.

The client must have completed a join to the multicast group. The destination address specified in the remoteEndPoint parameter must have already sent a multicast packet to this receiver. Some protocols use this information to pass along flow control, quality of service statistics, or recovery messages.

The method specified in the callback parameter is invoked when a packet has been sent.

The transmission is only allowed if the address specified in the remoteEndPoint parameter has already sent a multicast packet to this receiver. If the client is not allowed access, a SocketException is thrown with SocketError.AccessDenied.

If the destination port specified in the remoteEndPoint parameter is less than 1,024, a SocketException is thrown with SocketError.AccessDenied.

It is possible to have a socket failure if a send operation fails synchronously, although this is uncommon with UDP. If a socket failure occurs, a SocketException is thrown. The error received is specified as a member of the System.Net.Sockets.SocketError enumeration.

Version Information

Silverlight

Supported in: 5, 4

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

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