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

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.


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

Supported in: 4.6, 4.5, 4, 3.5, 3.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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