GestureRecognizer.Recognize(StrokeCollection) Method

Definition

Looks for gestures in the specified StrokeCollection.

public:
 System::Collections::ObjectModel::ReadOnlyCollection<System::Windows::Ink::GestureRecognitionResult ^> ^ Recognize(System::Windows::Ink::StrokeCollection ^ strokes);
[System.Security.SecurityCritical]
public System.Collections.ObjectModel.ReadOnlyCollection<System.Windows.Ink.GestureRecognitionResult> Recognize (System.Windows.Ink.StrokeCollection strokes);
public System.Collections.ObjectModel.ReadOnlyCollection<System.Windows.Ink.GestureRecognitionResult> Recognize (System.Windows.Ink.StrokeCollection strokes);
[<System.Security.SecurityCritical>]
member this.Recognize : System.Windows.Ink.StrokeCollection -> System.Collections.ObjectModel.ReadOnlyCollection<System.Windows.Ink.GestureRecognitionResult>
member this.Recognize : System.Windows.Ink.StrokeCollection -> System.Collections.ObjectModel.ReadOnlyCollection<System.Windows.Ink.GestureRecognitionResult>
Public Function Recognize (strokes As StrokeCollection) As ReadOnlyCollection(Of GestureRecognitionResult)

Parameters

strokes
StrokeCollection

The StrokeCollection to search for gestures.

Returns

An array of type GestureRecognitionResult that contains application gestures that the GestureRecognizer recognized.

Attributes

Examples

The following example demonstrates how to determine whether a Stroke is a ScratchOut gesture.

private bool InterpretScratchoutGesture(Stroke stroke)
{
    // Attempt to instantiate a recognizer for scratchout gestures.
    ApplicationGesture[] gestures = { ApplicationGesture.ScratchOut };
    GestureRecognizer recognizer = new GestureRecognizer(gestures);

    if (!recognizer.IsRecognizerAvailable)
        return false;

    // Determine if the stroke was a scratchout gesture.
    StrokeCollection gestureStrokes = new StrokeCollection();
    gestureStrokes.Add(stroke);

    ReadOnlyCollection<GestureRecognitionResult> results = recognizer.Recognize(gestureStrokes);

    if (results.Count == 0)
        return false;

    // Results are returned sorted in order strongest-to-weakest; 
    // we need only analyze the first (strongest) result.
    if (results[0].ApplicationGesture == ApplicationGesture.ScratchOut &&
          results[0].RecognitionConfidence == RecognitionConfidence.Strong)
    {
        // Use the scratchout stroke to perform hit-testing and 
        // erase existing strokes, as necessary.
        return true;
    }
    else
    {
        // Not a gesture: display the stroke normally.
        return false;
    }
}
Private Function InterpretScratchoutGesture(ByVal stroke As Stroke) As Boolean
    ' Attempt to instantiate a recognizer for scratchout gestures.
    Dim gestures() As ApplicationGesture = {ApplicationGesture.ScratchOut}

    Dim recognizer As New GestureRecognizer(gestures)

    If Not recognizer.IsRecognizerAvailable Then
        Return False
    End If

    ' Determine if the stroke was a scratchout gesture.
    Dim gestureStrokes As StrokeCollection = New StrokeCollection()
    gestureStrokes.Add(stroke)

    Dim results As ReadOnlyCollection(Of GestureRecognitionResult)
    results = recognizer.Recognize(gestureStrokes)

    If results.Count = 0 Then
        Return False
    End If

    ' Results are returned sorted in order strongest-to-weakest; 
    ' we need only analyze the first (strongest) result.
    If (results(0).ApplicationGesture = ApplicationGesture.ScratchOut) Then

        ' Use the scratchout stroke to perform hit-testing and 
        ' erase existing strokes, as necessary.
        Return True
    Else
        ' Not a gesture: display the stroke normally.
        Return False
    End If
End Function

Remarks

The array returned by the Recognize method is sorted by the GestureRecognitionResult.RecognitionConfidence property. For example, Recognize may return a GestureRecognitionResult array with the following values:

Index ApplicationGesture RecognitionConfidence
0 Check Strong
1 NoGesture Intermediate
2 Curlicue Poor
3 DoubleCurlicue Poor

This means that the GestureRecognizer recognizes that it is very likely that the Stroke is a check mark, relatively likely that the Stroke in not a gesture, and not at all likely that the Stroke is a curlicue or a double curlicue.

Note

The Recognize method can return an array with NoGesture at a higher RecognitionConfidence than other application gestures. This means that it is more likely that the Stroke is not a gesture, as opposed to a gesture that has a lower RecognitionConfidence.

Applies to