RecognizerContext.BackgroundRecognize - метод (Object)

Статья
11/04/2008

Обновлен: Ноябрь 2007

Causes the Recognizer object to recognize the associated Strokes collection and raise a Recognition event, with associated application data, when recognition is complete.

Пространство имен: Microsoft.Ink
Сборка: Microsoft.Ink (в Microsoft.Ink.dll)

Синтаксис

'Декларация
Public Sub BackgroundRecognize ( _
    customData As Object _
)
'Применение
Dim instance As RecognizerContext
Dim customData As Object

instance.BackgroundRecognize(customData)

public void BackgroundRecognize(
    Object customData
)

public:
void BackgroundRecognize(
    Object^ customData
)

public void BackgroundRecognize(
    Object customData
)

public function BackgroundRecognize(
    customData : Object
)

Параметры

customData
Тип: System.Object
Any application-defined data that is available to the application in the Recognition event. The default value is null (Nothing in Microsoft® Visual Basic® .NET).

Заметки

This method specifies that ink recognition is performed asynchronously. To recognize ink synchronously, call the RecognizerContext.Recognize method.

This method recognizes only the best result string. This method does not create RecognitionAlternate objects. To perform recognition that creates a list of available alternates, call the BackgroundRecognizeWithAlternates method.

The Recognition event is not raised if the recognizer does not recognize anything.

Примеры

In this example, each stroke made in an InkOverlay object is automatically recognized and the recognition result displayed.

When the Stroke event fires (in response to the user completing a stroke), the newly created stroke is added to the Strokes collection of the RecognizerContext object, and the BackgroundRecognize method is called, passing the current time to the customData parameter.

Private Sub mInkOverlay_Stroke4(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(DateTime.Now)
End Sub

private void mInkOverlay_Stroke4(object sender, InkCollectorStrokeEventArgs e)
{
    // in case background recognition is still occurring, stop it
    mRecognizerContext.StopBackgroundRecognition();
    // add the stroke, and start recognition, passing current time
    mRecognizerContext.Strokes.Add(e.Stroke);
    mRecognizerContext.BackgroundRecognize(DateTime.Now);
}

When background recognition is complete, the Recognition event fires. During handling of this event, the results of the recognition are placed in a list box. In addition, the time that recognition began is retrieved from the CustomData property of the RecognizerContextRecognitionEventArgs object, and used to calculate the total elapsed time required for recognition.

' event fires when recognition results (without alternates) are ready
Private Sub RecognizerContext_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 RecognizerContext_Recognition), _
            New Object() {sender, e} _
        )
        Return
    End If
    If RecognitionStatus.NoError = e.RecognitionStatus Then
        listBoxRecognitionResults.Items.Add(e.Text)
        ' get the custom data and calculate elapsed time
        Dim startTime As DateTime = DirectCast(e.CustomData, DateTime)
        Dim endTime As DateTime = DateTime.Now
        Dim span As TimeSpan = New TimeSpan(endTime.Ticks - startTime.Ticks)
        ' display the number of seconds for this recognition to finish
        listBoxRecognitionResults.Items.Add(span.TotalSeconds.ToString())
    End If
End Sub

// event fires when recognition results (without alternates) are ready
private void RecognizerContext_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(RecognizerContext_Recognition),
            new object[] { sender, e }
            );
        return;
    }

    if (RecognitionStatus.NoError == e.RecognitionStatus)
    {
        listBoxRecognitionResults.Items.Add(e.Text);
        // get the custom data and calculate elapsed time
        DateTime startTime = (DateTime)e.CustomData;
        DateTime endTime = DateTime.Now;
        TimeSpan span = new TimeSpan(endTime.Ticks - startTime.Ticks);
        // display the number of seconds for this recognition to finish
        listBoxRecognitionResults.Items.Add(span.TotalSeconds.ToString());
    }
}

Платформы

Windows Vista

Среды .NET Framework и .NET Compact Framework поддерживают не все версии каждой платформы. Поддерживаемые версии перечислены в разделе Требования к системе для .NET Framework.