Increments an object's count of its strong external connections (links).

HRESULT AddConnection(

DWORD exconn,
//Type of external connection
DWORD dwreserved
//Used by OLE to pass connection information



[out] Specifies the type of external connection to the object. The only type of external connection currently supported by this interface is strong, which means that the object must remain alive as long as this external connection exists. Strong external connections are represented by the value EXTCONN_STRONG = 0x0001, which is defined in the enumeration EXTCONN.


Passes information about the connection. This parameter is reserved for use by OLE. Its value can be zero, but not necessarily. Therefore, implementations of AddConnection should not contain blocks of code whose execution depends on whether a zero value is returned.

Return Value


The number of reference counts on the object; used for debugging purposes only.


An object created by a EXE object application relies on its stub manager to call IExternalConnection::AddConnection whenever a link client activates and therefore creates an external lock on the object. When the link client breaks the connection, the stub manager calls IExternalConnection::ReleaseConnection to release the lock.

Since DLL object applications exist in the same process space as their objects, they do not utilize RPC (remote procedure calls) and therefore do not have stub managers to keep track of external connections. Therefore, DLL object applications that support external links to their objects must implement IExternalConnection so link clients can directly call the interface to inform them when connections are added or released.

The following is a typical implementation for the AddConnection method:

DWORD XX::AddConnection(DWORD extconn, DWORD dwReserved)
return extconn&EXTCONN_STRONG ? ++m_cStrong : 0;

See Also

IExternalConnection::ReleaseConnection, IRunnableObject::LockRunning, OleLockRunning

Software for developers
Delphi Components
.Net Components
Software for Android Developers
More information resources
Unix Manual Pages
Delphi Examples
Databases for Amazon shops developers
Amazon Categories Database
Browse Nodes Database