OnToolAddBlock Method of the IImageViewerEvents Interface

This method is implemented on the client-side. It is called by ABBYY FineReader Engine before adding a new block that has been drawn with the help of one of the following tools of Image Viewer:

See the description of the Image Viewer Commands to know how these tools can be selected.

It delivers to the client information about the block that has been drawn: its type and region. With the help of this method it is possible to cancel the operation.



HRESULT OnToolAddBlock(
  BlockTypeEnum type,
  IFRRectangle* BlockRect,


void OnToolAddBlock(
  BlockTypeEnum type,
  IFRRectangle   BlockRect,
  out bool      Cancel

Visual Basic .NET

Sub OnToolAddBlock( _
  type As BlockTypeEnum, _
  BlockRect As IFRRectangle, _
  ByRef Cancel As Boolean _


[in] Contains the type of the block. See the description of the BlockTypeEnum constants.
[in] Contains the coordinates of the block. Coordinates are represented by the FRRectangle object. The coordinates are specified in pixels relative to the document image.
[out] You may set this variable to TRUE to indicate that the process should be terminated. In this case, the block will not be created.

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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