OnProgress Method of the IZoomViewerEvents Interface

This method is implemented on the client-side. It is called by ABBYY FineReader Engine during analysis or recognition of the active page in Zoom Viewer. The process can be invoked in one of the following ways:

To find how these commands can be called, refer to the Zoom Viewer Commands list.

To find how these commands can be called, refer to the Image Viewer Commands list.

To find how these commands can be called, refer to the Document Viewer Commands list.

  • via FineReader Engine API

It delivers to the client approximate percentage of the operation. Its implementation may show a progress indicator. It may also process any Windows messages to avoid an effect that the application "is not responding" during long operations. With the help of this method it is possible to cancel the operation.



HRESULT OnProgress(
  int           Percentage,


void OnProgress(
  int      Percentage,
  out bool Cancel

Visual Basic .NET

Sub OnProgress( _
  Percentage As Integer, _
  ByRef Cancel As Boolean _


[in] Contains the percent of the work currently done. It is in the range from 0 to 100.
[out] You may set this variable to TRUE to indicate that the process should be terminated. In this case, the analysis or recognition process will be aborted.

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



24.03.2023 8:51:52

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