RecognizerContext.Recognition 事件

项目
11/04/2008

在 RecognizerContext 对象通过 BackgroundRecognize 方法生成结果之后发生。

命名空间： Microsoft.Ink
程序集： Microsoft.Ink（在 Microsoft.Ink.dll 中）

语法

声明
Public Event Recognition As RecognizerContextRecognitionEventHandler
用法
Dim instance As RecognizerContext
Dim handler As RecognizerContextRecognitionEventHandler

AddHandler instance.Recognition, handler

public event RecognizerContextRecognitionEventHandler Recognition

public:
 event RecognizerContextRecognitionEventHandler^ Recognition {
    void add (RecognizerContextRecognitionEventHandler^ value);
    void remove (RecognizerContextRecognitionEventHandler^ value);
}

/** @event */
public void add_Recognition (RecognizerContextRecognitionEventHandler value)
/** @event */
public void remove_Recognition (RecognizerContextRecognitionEventHandler value)

JScript 不支持事件。

备注

事件处理程序接收 RecognizerContextRecognitionEventArgs 类型的参数，该参数包含有关此事件的数据。

创建 RecognizerContextRecognitionEventHandler 委托时，需要标识将处理该事件的方法。若要将该事件与事件处理程序关联，请将该委托的一个实例添加到事件中。除非移除了该委托，否则每当发生该事件时就会调用此事件处理程序。

如果尝试从识别事件处理程序访问原始 RecognizerContext 对象，则应用程序编程接口 (API) 的行为将不可预知。请不要尝试这么做。如果确实需要，正确的做法是在 Recognition 事件处理程序中创建一个标志并对其进行设置。然后，可以在该事件处理程序外部轮询该标志以确定何时更改 RecognizerContext 属性。

示例

此示例自动识别在 InkOverlay 对象中创建的每个笔画，并显示识别结果。

在应用程序启动期间，将实例化 RecognizerContext 对象并分配事件处理程序。

' create a new RecognizerContext object
' the object's Strokes property is initialized to null
mRecognizerContext = New RecognizerContext()
' assign the Strokes property by creating a fresh Strokes collection 
mRecognizerContext.Strokes = mInkOverlay.Ink.CreateStrokes()
' subscribe to the Strokes event. It is during this event
' that we can add strokes to the RecognizerContext
AddHandler mInkOverlay.Stroke, New InkCollectorStrokeEventHandler(AddressOf mInkOverlay_Stroke2)
' subscribe to the the Recognition event. 
' This event is fired when background recognition is complete, 
' and recognition results (without alternates) are available
AddHandler mRecognizerContext.Recognition, _
        New RecognizerContextRecognitionEventHandler(AddressOf mRecognizerContext_Recognition)

// create a new RecognizerContext object
// the object's Strokes property is initialized to null
mRecognizerContext = new RecognizerContext();
// assign the Strokes property by creating a fresh Strokes collection 
mRecognizerContext.Strokes = mInkOverlay.Ink.CreateStrokes();
// subscribe to the Strokes event. It is during this event
// that we can add strokes to the RecognizerContext
mInkOverlay.Stroke += new InkCollectorStrokeEventHandler(mInkOverlay_Stroke2);
// subscribe to the the Recognition event. 
// This event is fired when background recognition is complete, 
// and recognition results (without alternates) are available
mRecognizerContext.Recognition += 
    new RecognizerContextRecognitionEventHandler(mRecognizerContext_Recognition);

在激发 Stroke 事件（对用户完成笔画做出的响应）时，会将新创建的笔画添加到 RecognizerContext 对象的 Strokes 集合中，并调用 BackgroundRecognize 方法。

Private Sub mInkOverlay_Stroke2(ByVal sender As Object, ByVal e As InkCollectorStrokeEventArgs)
    ' in case background recognition is still occurring, stop it
    mRecognizerContext.StopBackgroundRecognition()
    ' add the stroke, and start recognition
    mRecognizerContext.Strokes.Add(e.Stroke)
    mRecognizerContext.BackgroundRecognize()
End Sub

private void mInkOverlay_Stroke2(object sender, InkCollectorStrokeEventArgs e)
{
    // in case background recognition is still occurring, stop it
    mRecognizerContext.StopBackgroundRecognition();
    // add the stroke, and start recognition
    mRecognizerContext.Strokes.Add(e.Stroke);
    mRecognizerContext.BackgroundRecognize();
}

完成后台识别时将激发 Recognition 事件。在处理此事件的过程中，会将识别结果放入一个列表框。

' event fires when recognition results (without alternates) are ready
Private Sub mRecognizerContext_Recognition(ByVal sender As Object, _
            ByVal e As RecognizerContextRecognitionEventArgs)
    ' when updating a control, must use Invoke() since controls are
    ' not thread safe and recognition occurs on a different thread
    If Me.InvokeRequired Then
        ' recursively call this method via Invoke()
        Me.Invoke( _
            New RecognizerContextRecognitionEventHandler(AddressOf mRecognizerContext_Recognition), _
            New Object() {sender, e} _
        )
        Return
    End If
    If RecognitionStatus.NoError = e.RecognitionStatus Then
        listBoxRecognitionResults.Items.Add(e.Text)
    End If
End Sub

// event fires when recognition results (without alternates) are ready
private void mRecognizerContext_Recognition(object sender, RecognizerContextRecognitionEventArgs e)
{
    // when updating a control, must use Invoke() since controls are
    // not thread safe and recognition occurs on a different thread
    if (this.InvokeRequired)
    {
        // recursively call this method via Invoke()
        this.Invoke(
            new RecognizerContextRecognitionEventHandler(mRecognizerContext_Recognition), 
            new object[] { sender, e }
            );
        return;
    }
    if (RecognitionStatus.NoError == e.RecognitionStatus)
    {
        listBoxRecognitionResults.Items.Add(e.Text);
    }
}