Using Restart Manager with an External UI
Specify the INSTALLLOGMODE_RMFILESINUSE message type when calling the MsiSetExternalUI or MsiSetExternalUIRecord function to enable the external user-interface handler. Windows Installer then sends an INSTALLMESSAGE_RMFILESINUSE message for use by external user-interface handlers that support the Restart Manager.
Your external user-interface handler should handle the information contained in INSTALLMESSAGE_RMFILESINUSE messages. If no registered or internal user-interface handles the INSTALLMESSAGE_RMFILESINUSE message, Windows Installer sends an INSTALLMESSAGE_FILESINUSE message for use by existing external handlers that support INSTALLMESSAGE_FILESINUSE messages and the FilesInUse dialog box.
The external user interface can return the values listed in the following table.
|External UI return value||Action taken by Windows Installer|
|IDOK||The OK button was pressed by the user. The Windows Installer will request that the Restart Manager shut down and restart the applications that hold files currently in use.|
|IDCANCEL||The CANCEL button was pressed. Cancel the installation.|
|IDIGNORE||The IGNORE button was pressed. Ignore and continue the installation. A restart will be required at the end of the installation.|
|IDNO||The NO button was pressed. If the package has an MsiRMFilesInUse dialog box, send a 1610 message. For more information, see Windows Installer Error Messages. If the package does not have a MsiRMFilesInUse dialog box, send an INSTALLMESSAGE_FILESINUSE message.|
|IDRETRY||The RETRY button was pressed. Send the INSTALLMESSAGE_FILESINUSE message.|
|-1||An error. End the installation.|