ITextView.ViewportTop Property   
Definition
Important
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Gets the position of the top edge of the viewport in the text rendering coordinate system.
public:
 property double ViewportTop { double get(); };
	public:
 property double ViewportTop { double get(); };
	public double ViewportTop { get; }
	member this.ViewportTop : double
	Public ReadOnly Property ViewportTop As Double
	Property Value
The top edge of the viewport.
Remarks
Scrolling the text is done by changing the set of formatted lines and/or the vertical offset of those lines.