| Platform SDK: Transaction Server |
[This product will work only on Windows NT 4.0 versions and earlier. For Windows 2000 and later, see COM+ (Component Services).]
Implementing this method allows an MTS object to perform context-specific initialization whenever it's activated. This method is called by the MTS run-time environment before any other methods are called on the object.
Provided By
HRESULT IObjectControl::Activate ( );
Return Values
S_OK
The Activate method succeeded.
Failure HRESULT
Any error code indicating why an object was unable to activate itself.
Remarks
Whenever a client calls an MTS object that isn't already activated, the MTS run-time environment automatically activates the object. This is called just-in-time activation. For components that support the IObjectControl interface, MTS invokes the object's Activate method before passing the client's method call on to the object. This allows objects to do context-specific initialization.
Because an object's context isn't available during object construction, you can't perform any initialization that involves the ObjectContextinside the constructor. Instead, you should implement the Activate method and place all your context-specific initialization procedures there.
For example, you can use the Activate method to obtain a reference to an object's context and store it in a member variable. Then the context reference is available to any method that requires it, and you don't have to acquire a new one and then release it every time you use it. Once you have a reference to the object's context, you can use the IObjectContext methods to check whether security is enabled, whether the object is executing in a transaction, or whether the caller is in a particular role. You can also use the Activate method to obtain a reference to the object's SecurityProperty and check the security ID of the object's creator before any methods are called.
If you're enabling object recycling (returning TRUE from the CanBePooled method), the Activate method must be able to handle both newly created and recycled objects. When the Activate method returns, there should be no distinguishable difference between a new object and a recycled one.
See Also