StrokeCollection.HitTest Method (IEnumerable<Point>, Int32)


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Returns a collection of strokes that have at least the specified percentage of length within the specified area.

Namespace:   System.Windows.Ink
Assembly:  PresentationCore (in PresentationCore.dll)

public StrokeCollection HitTest(
	IEnumerable<Point> lassoPoints,
	int percentageWithinLasso


Type: System.Collections.Generic.IEnumerable<Point>

An array of type Point that represents the bounds of the area to be hit tested.

Type: System.Int32

The acceptable length of the Stroke, as a percentage, for lassoPoints to contain.

Return Value

Type: System.Windows.Ink.StrokeCollection

A StrokeCollection that has strokes with at least the specified percentage within the Point array.

Exception Condition

lassoPoints is null.


percentageWithinLasso is null.


lassoPoints contains an empty array.


percentageWithinLasso is less than 0 or greater than 100.

The following example demonstrates how to remove all strokes that are at least 80 percent within the specified lasso from a StrokeCollection. This is useful when a custom control enables the user to select ink with a lasso. To create a control that enables a user to select ink with a lasso, see How to: Select Ink from a Custom Control.

// Remove the strokes within the lasso from the InkPresenter
public void RemoveStrokes(Point[] lasso)
    StrokeCollection strokes = presenter.Strokes.HitTest(lasso, 80);



.NET Framework
Available since 3.0
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