Class SteamNetworkingMessages

The non-connection-oriented interface to send and receive messages (whether they be "clients" or "servers"). ISteamNetworkingSockets is connection-oriented (like TCP), meaning you need to listen and connect, and then you send messages using a connection handle. ISteamNetworkingMessages is more like UDP, in that you can just send messages to arbitrary peers at any time. The underlying connections are established implicitly. Under the hood ISteamNetworkingMessages works on top of the ISteamNetworkingSockets code, so you get the same routing and messaging efficiency. The difference is mainly in your responsibility to explicitly establish a connection and the type of feedback you get about the state of the connection. Both interfaces can do "P2P" communications, and both support both unreliable and reliable messages, fragmentation and reassembly. The primary purpose of this interface is to be "like UDP", so that UDP-based code can be ported easily to take advantage of relayed connections. If you find yourself needing more low level information or control, or to be able to better handle failure, then you probably need to use ISteamNetworkingSockets directly. Also, note that if your main goal is to obtain a connection between two peers without concerning yourself with assigning roles of "client" and "server", you may find the symmetric connection mode of ISteamNetworkingSockets useful. (See k_ESteamNetworkingConfig_SymmetricConnect.)

Inheritance

object

SteamNetworkingMessages

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Namespace: Unity.Steamworks.Interop

Assembly: Unity.Steamworks.Interop.dll

Syntax

public static class SteamNetworkingMessages

Methods

AcceptSessionWithUser(ref SteamNetworkingIdentity)

Call this in response to a SteamNetworkingMessagesSessionRequest_t callback. SteamNetworkingMessagesSessionRequest_t are posted when a user tries to send you a message, and you haven't tried to talk to them first. If you don't want to talk to them, just ignore the request. If the user continues to send you messages, SteamNetworkingMessagesSessionRequest_t callbacks will continue to be posted periodically. Returns false if there is no session with the user pending or otherwise. If there is an existing active session, this function will return true, even if it is not pending. Calling SendMessageToUser() will implicitly accepts any pending session request to that user.

Declaration

public static bool AcceptSessionWithUser(ref SteamNetworkingIdentity identityRemote)

Parameters

Type	Name	Description
SteamNetworkingIdentity	identityRemote	Passed through to ISteamNetworkingMessages::AcceptSessionWithUser.

Returns

Type	Description
bool	The value ISteamNetworkingMessages::AcceptSessionWithUser returns.

CloseChannelWithUser(ref SteamNetworkingIdentity, int)

Call this when you're done talking to a user on a specific channel. Once all open channels to a user have been closed, the open session to the user will be closed, and any new data from this user will trigger a SteamSteamNetworkingMessagesSessionRequest_t callback

Declaration

public static bool CloseChannelWithUser(ref SteamNetworkingIdentity identityRemote, int nLocalChannel)

Parameters

Type	Name	Description
SteamNetworkingIdentity	identityRemote	Passed through to ISteamNetworkingMessages::CloseChannelWithUser.
int	nLocalChannel	Passed through to ISteamNetworkingMessages::CloseChannelWithUser.

Returns

Type	Description
bool	The value ISteamNetworkingMessages::CloseChannelWithUser returns.

CloseSessionWithUser(ref SteamNetworkingIdentity)

Call this when you're done talking to a user to immediately free up resources under-the-hood. If the remote user tries to send data to you again, another SteamNetworkingMessagesSessionRequest_t callback will be posted. Note that sessions that go unused for a few minutes are automatically timed out.

Declaration

public static bool CloseSessionWithUser(ref SteamNetworkingIdentity identityRemote)

Parameters

Type	Name	Description
SteamNetworkingIdentity	identityRemote	Passed through to ISteamNetworkingMessages::CloseSessionWithUser.

Returns

Type	Description
bool	The value ISteamNetworkingMessages::CloseSessionWithUser returns.

GetSessionConnectionInfo(ref SteamNetworkingIdentity, out SteamNetConnectionInfo_t, out SteamNetConnectionRealTimeStatus_t)

Returns information about the latest state of a connection, if any, with the given peer. Primarily intended for debugging purposes, but can also be used to get more detailed failure information. (See SendMessageToUser and k_nSteamNetworkingSend_AutoRestartBrokenSession.) Returns the value of SteamNetConnectionInfo_t::m_eState, or k_ESteamNetworkingConnectionState_None if no connection exists with specified peer. You may pass nullptr for either parameter if you do not need the corresponding details. Note that sessions time out after a while, so if a connection fails, or SendMessageToUser returns k_EResultNoConnection, you cannot wait indefinitely to obtain the reason for failure.

Declaration

public static ESteamNetworkingConnectionState GetSessionConnectionInfo(ref SteamNetworkingIdentity identityRemote, out SteamNetConnectionInfo_t pConnectionInfo, out SteamNetConnectionRealTimeStatus_t pQuickStatus)

Parameters

Type	Name	Description
SteamNetworkingIdentity	identityRemote	Passed through to ISteamNetworkingMessages::GetSessionConnectionInfo.
SteamNetConnectionInfo_t	pConnectionInfo	Passed through to ISteamNetworkingMessages::GetSessionConnectionInfo.
SteamNetConnectionRealTimeStatus_t	pQuickStatus	Passed through to ISteamNetworkingMessages::GetSessionConnectionInfo.

Returns

Type	Description
ESteamNetworkingConnectionState	The value ISteamNetworkingMessages::GetSessionConnectionInfo returns.

ReceiveMessagesOnChannel(int, IntPtr[], int)

Reads the next message that has been sent from another user via SendMessageToUser() on the given channel. Returns number of messages returned into your list. (0 if no message are available on that channel.) When you're done with the message object(s), make sure and call SteamNetworkingMessage_t::Release()!

Declaration

public static int ReceiveMessagesOnChannel(int nLocalChannel, IntPtr[] ppOutMessages, int nMaxMessages)

Parameters

Type	Name	Description
int	nLocalChannel	Passed through to ISteamNetworkingMessages::ReceiveMessagesOnChannel.
IntPtr[]	ppOutMessages	Passed through to ISteamNetworkingMessages::ReceiveMessagesOnChannel.
int	nMaxMessages	Passed through to ISteamNetworkingMessages::ReceiveMessagesOnChannel.

Returns

Type	Description
int	The value ISteamNetworkingMessages::ReceiveMessagesOnChannel returns.

SendMessageToUser(ref SteamNetworkingIdentity, IntPtr, uint, int, int)

Sends a message to the specified host. If we don't already have a session with that user, a session is implicitly created. There might be some handshaking that needs to happen before we can actually begin sending message data. If this handshaking fails and we can't get through, an error will be posted via the callback SteamNetworkingMessagesSessionFailed_t. There is no notification when the operation succeeds. (You should have the peer send a reply for this purpose.) Sending a message to a host will also implicitly accept any incoming connection from that host. nSendFlags is a bitmask of k_nSteamNetworkingSend_xxx options nRemoteChannel is a routing number you can use to help route message to different systems. You'll have to call ReceiveMessagesOnChannel() with the same channel number in order to retrieve the data on the other end. Using different channels to talk to the same user will still use the same underlying connection, saving on resources. If you don't need this feature, use 0. Otherwise, small integers are the most efficient. It is guaranteed that reliable messages to the same host on the same channel will be be received by the remote host (if they are received at all) exactly once, and in the same order that they were sent. NO other order guarantees exist! In particular, unreliable messages may be dropped, received out of order with respect to each other and with respect to reliable data, or may be received multiple times. Messages on different channels are not guaranteed to be received in the order they were sent. A note for those familiar with TCP/IP ports, or converting an existing codebase that opened multiple sockets: You might notice that there is only one channel, and with TCP/IP each endpoint has a port number. You can think of the channel number as the destination port. If you need each message to also include a "source port" (so the recipient can route the reply), then just put that in your message. That is essentially how UDP works! Returns:

• k_EREsultOK on success.
• k_EResultNoConnection, if the session has failed or was closed by the peer and k_nSteamNetworkingSend_AutoRestartBrokenSession was not specified. (You can use GetSessionConnectionInfo to get the details.) In order to acknowledge the broken session and start a new one, you must call CloseSessionWithUser, or you may repeat the call with k_nSteamNetworkingSend_AutoRestartBrokenSession. See k_nSteamNetworkingSend_AutoRestartBrokenSession for more details.
• See ISteamNetworkingSockets::SendMessageToConnection for more possible return values

Declaration

public static EResult SendMessageToUser(ref SteamNetworkingIdentity identityRemote, IntPtr pubData, uint cubData, int nSendFlags, int nRemoteChannel)

Parameters

Type	Name	Description
SteamNetworkingIdentity	identityRemote	Passed through to ISteamNetworkingMessages::SendMessageToUser.
IntPtr	pubData	Passed through to ISteamNetworkingMessages::SendMessageToUser.
uint	cubData	Passed through to ISteamNetworkingMessages::SendMessageToUser.
int	nSendFlags	Passed through to ISteamNetworkingMessages::SendMessageToUser.
int	nRemoteChannel	Passed through to ISteamNetworkingMessages::SendMessageToUser.

Returns

Type	Description
EResult	The value ISteamNetworkingMessages::SendMessageToUser returns.