TWAIN ActiveX/Plug-in HTTP Control/SDK

CurrentImageIndexInBuffer Property

Description

Returns or sets current index of image in buffer. This is a runtime property.

Data type

Short

Syntax

ObjectName.CurrentImageIndexInBuffer

Parameters

None.

Remarks

The index is 0 based.

By changing CurrentImageIndexInBuffer, you can enumerate all the images in buffer.

When CurrentImageIndexInBuffer is changed, the control will be redrawn to reflect the change.

When an image is added to buffer, the CurrentImageIndexInBuffer is skipped to the next one and the new image is added there.

When image buffer is full, that is HowManyImagesInBuffer = MaxImagesInBuffer, the new acquired or opened image will replace the existing one, positioned by CurrentImageIndexInBuffer.

For example, if HowManyImagesInBuffer = 4 and MaxImagesInBuffer = 4, CurrentImageIndexInBuffer = 3, after a new image is acquired, the CurrentImageIndexInBuffer is set to 0, and the 1st image is replaced by the new acquired one . If another image is acquired again, the CurrentImageIndexInBuffer is set to 1 and the 2nd image is replaced by the new acquired one.

When an error occurs and IfThrowException property is TRUE, an exception will be thrown. Check ErrorCode property and ErrorString property for error information.

Sample

The following sample shows how to move the current image index to the next one.

VB Sample:

Private Sub MoveToNextImage()
    
    If Twain.CurrentImageIndexInBuffer = Twain.HowManyImagesInBuffer -1 Then  'Last image in buffer
    	Twain.CurrentImageIndexInBuffer = 0
    Else
    	Twain.CurrentImageIndexInBuffer = Twain.CurrentImageIndexInBuffer + 1
    End If
        
End Sub