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# OnSelectionChanged Method of the ITextValidatorEvents Interface

> OnSelectionChanged method of the ITextValidatorEvents Interface in ABBYY FineReader Engine Visual Components on Windows — This method is implemented on the client-side.

This method is implemented on the client-side. It is called by ABBYY FineReader Engine after text selection has been changed in the [Text Validator](/fine-reader/engine/visual-components-reference/textvalidator).

It delivers to the client the cursor position of the beginning of the selection and the length of the selection.

## Syntax

### C++

```cpp theme={null}
HRESULT OnSelectionChanged(
  IEditorPosition* Position,
  int              Length
);
```

### C\#

```csharp theme={null}
void OnSelectionChanged(
  IEditorPosition Position,
  int            Length
);
```

### Visual Basic .NET

```vb theme={null}
Sub OnSelectionChanged( _
  Position As IEditorPosition, _
  Length As Integer _
)
```

## Parameters

Position

\[in] Refers to the [EditorPosition](/fine-reader/engine/visual-components-reference/supplementary-objects/editorposition) object that contains the cursor position of the beginning of the selection.

Length

\[in] Specifies the length of the selection.

## Return values

This method has no specific return values. It returns the [standard return values of ABBYY FineReader Engine functions](/fine-reader/engine/api-reference/return-codes).

## Remarks

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

[ITextValidatorEvents](/fine-reader/engine/visual-components-reference/itextvalidatorevents)