Gets or sets a coeficient which will determine in each layout pass the size of the viewport. If zero is specified the size of the viewport will be equal to the scrollviewer viewport. If 0.5 is specified the size of the viewport will be enlarged to take up half screen more at both sides of the original viewport.

'Declaration
 
Public Property ViewportGap As System.Double

public System.double ViewportGap {get; set;}