Windows Mobile 6.5
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This function registers an EXE class object with OLE so other applications can connect to it. EXE object applications should call CoRegisterClassObject on startup. It can also be used to register internal objects for use by the same EXE or other code (such as DLLs) that the EXE uses.

STDAPI CoRegisterClassObject(
  REFCLSID rclsid,
  IUnknown* pUnk,
  DWORD dwClsContext,
  DWORD flags,
  LPDWORD lpdwRegister


[in] CLSID to be registered.


[in] Pointer to the IUnknowninterface on the class object whose availability is being published.


[in] Context in which the executable code is to be run. For information on these context values, see the CLSCTX enumeration.


[in] How connections are made to the class object. For information on these flags, see the REGCLS enumeration.


[out] Pointer to a value that identifies the class object registered; later used by the CoRevokeClassObject function to revoke the registration.

This function supports the standard return values E_INVALIDARG, E_OUTOFMEMORY, and E_UNEXPECTED, as well as the following:


The class object was registered successfully.


Already registered in the class object table.

Only EXE object applications call CoRegisterClassObject. Object handlers or DLL object applications do not call this function — instead, they must implement and export the DllGetClassObject function.

At startup, a multiple-use EXE object application must create a class object (with the IClassFactory interface on it), and call CoRegisterClassObject to register the class object. Object applications that support several different classes (such as multiple types of embeddable objects) must allocate and register a different class object for each.

Multiple registrations of the same class object are independent and do not produce an error. Each subsequent registration yields a unique key in lpdwRegister.

Multiple document interface (MDI) applications must register their class objects. Single document interface (SDI) applications must register their class objects only if they can be started by means of the /Embedding switch.

The server for a class object should call CoRevokeClassObject to revoke the class object (remove its registration) when all of the following are true:

  • There are no existing instances of the object definition.
  • There are no locks on the class object.
  • The application providing services to the class object is not under user control (not visible to the user on the display).

After the class object is revoked, when its reference count reaches zero, the class object can be released, allowing the application to exit.

For information on the flags parameter, refer to the REGCLS enumeration.

To determine whether the platform supports this function, see Determining Supported COM APIs.

Windows Embedded CEWindows CE 3.0 and later
Windows MobileWindows Mobile Version 5.0 and later

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