OnCommand Method of the ICommandEvents Interface

This method is implemented on the client-side. It is called by ABBYY FineReader Engine before executing a command in Image Viewer, Zoom Viewer, Text Editor or Document Viewer.

See the list of available commands and the ways these commands can be used in each component:

The method delivers to the client information on the command which is going to be executed. With the help of this method it is possible to cancel the operation.



HRESULT OnCommand(
  MenuItemEnum  MenuItem,


void OnCommand(
  MenuItemEnum MenuItem,
  out bool     Cancel

Visual Basic .NET

Sub OnCommand( _
  MenuItem As MenuItemEnum, _
  ByRef Cancel As Boolean _


[in] This variable of the MenuItemEnum type specifies the command which has been called.
[out] You may set this variable to TRUE to indicate that the process should be terminated. In this case, the command will not be executed.

Return values

[C++ only] If this method returns a value other than S_OK, it indicates that an error occurred on the client-side, and in this case the value of the Cancel parameter is not taken into account.


The client implementation of this method must assure that all exceptions thrown inside the method are caught and handled and no exceptions are propagated outside the method. Propagation of an exception outside the method may lead to unpredictable results (such as program termination).

See also


Customizing the Context Menu and Toolbar of a Visual Component

24.03.2023 8:51:52

Usage of Cookies. In order to optimize the website functionality and improve your online experience ABBYY uses cookies. You agree to the usage of cookies when you continue using this site. Further details can be found in our Privacy Notice.