| -api-id | -api-type |
|---|---|
M:Windows.Networking.Sockets.StreamSocket.ConnectAsync(Windows.Networking.HostName,System.String,Windows.Networking.Sockets.SocketProtectionLevel,Windows.Networking.Connectivity.NetworkAdapter) |
winrt method |
Starts an asynchronous operation on a StreamSocket object on a specified local network adapter to connect to a remote destination specified by a remote hostname, a remote service name, and a SocketProtectionLevel.
The hostname or IP address of the remote network destination. For Bluetooth RFCOMM, this is a MAC address.
The service name or TCP port number of the remote network destination. For Bluetooth RFCOMM, this is the Bluetooth address.
The protection level that represents the integrity and encryption for the StreamSocket object.
The local network adapter to use for the connect operation on the StreamSocket object.
An asynchronous connect operation on a StreamSocket object.
The [ConnectAsync(Hostname, String, SocketProtectionLevel, NetworkAdapter) method binds to a network interface specified in the adapter parameter on the local computer and the remote hostname and service name specified in the remoteHostName and remoteServiceName parameters with the protection level specified in the protectionLevel parameter.
The remoteHostName and remoteServiceName parameters must be provided. If the remoteHostName is null or the remoteServiceName is null or an empty string, an error will occur. If the adapter parameter is null, an error will occur.
The name resolution mechanism used by the [ConnectAsync(Hostname, String, SocketProtectionLevel, NetworkAdapter) method is limited to the specified interface for the domain name system (DNS) namespace.
Using the specified network adapter is on a best-effort basis. Systems with adapters configured in weak-host or forwarding modes may use an adapter other than the specified adapter.
When the protectionLevel parameter is set to a value that requires SSL or TLS, the socket connect operation may not timeout if the remote network destination does not support SSL or TLS. This can occur if initial connect operation succeeds but the remote host does not terminate the connection during the SSL handshake. To protect against this situation, an app should set a timeout on the connect operation when requesting SSL/TLS and abort the operation if the timeout expires. For more information on setting a timeout using JavaScript on socket operations, see How to set timeouts on socket operations . For more information on setting a timeout using VB, C#, or C++ on socket operations, see How to set timeouts on socket operations .
An app can retrieve a valid NetworkAdapter by inspecting a HostName instance (using the NetworkInformation.GetHostNames method, for example) and retrieving the IPInformation object from the Hostname.IPInformation property. The IPInformation.NetworkAdapter property can be used to retrieve the associated NetworkAdapter.
In a UWP app, the StreamSocket class supports connecting to a remote endpoint when proxies are required to complete the connection. This support for proxies is automatic and transparent to the app. However, connecting through proxies is not supported when a specific network adapter is selected. So proxy support is disabled when the [ConnectAsync(HostName, String, SocketProtectionLevel, NetworkAdapter) method is used. For more detailed information, see the remarks on Support for proxies in the StreamSocket class reference.
In a Windows Phone 8.x app, the StreamSocket class does not provide automatic support for proxies.
How to set timeouts on socket operations , How to set timeouts on socket operations , ConnectAsync(EndpointPair), ConnectAsync(HostName, String), ConnectAsync(EndpointPair, SocketProtectionLevel), ConnectAsync(HostName, String, SocketProtectionLevel), IPInformation, NetworkAdapter