GestureRecognizer 类

定义

public ref class GestureRecognizer sealed : System::Windows::DependencyObject, IDisposable

public sealed class GestureRecognizer : System.Windows.DependencyObject, IDisposable

type GestureRecognizer = class
    inherit DependencyObject
    interface IDisposable

Public NotInheritable Class GestureRecognizer
Inherits DependencyObject
Implements IDisposable

继承

Object

DispatcherObject

DependencyObject

GestureRecognizer

实现

IDisposable

示例

以下示例演示如何确定某个 Stroke 手势是否为 ScratchOut 手势。

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

注解

GestureRecognizer标识墨迹笔势。 可以设置 GestureRecognizer 用于识别应用程序手势的所有或子集。 若要设置 GestureRecognizer 识别可用手势的子集，请将数组传递给 ApplicationGesture 构造函数或使用 SetEnabledGestures 该方法。 若要确定 StrokeCollection 是否包含手势，请调用 Recognize 该方法。

XAML 文本用法

不能在 XAML 中使用此类。