Riconoscimento della grafia

Questa sezione illustra alcune nozioni di base del riconoscimento relativamente all'input penna digitale nella piattaforma WPF.

Soluzioni di riconoscimento

Nell'esempio seguente viene mostrato come riconoscere l'input penna usando la classe Microsoft.Ink.InkCollector.

Creare un nuovo progetto di applicazione WPF in Visual Studio denominato InkRecognition. Sostituire il contenuto del file Window1.xaml con il codice XAML seguente. Questo codice esegue il rendering dell'interfaccia utente dell'applicazione.

<Window x:Class="InkRecognition.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="InkRecognition" 
    >
  <Canvas Name="theRootCanvas">
    <Border
      Background="White"
      BorderBrush="Black"
      BorderThickness="2"
      Height="300"
      Width="300"
      Canvas.Top="10"
      Canvas.Left="10">
      <InkCanvas Name="theInkCanvas"></InkCanvas>
    </Border>
    <TextBox Name="textBox1"
      Height="25"
      Width="225"
      Canvas.Top="325"
      Canvas.Left="10"></TextBox>
    <Button
      Height="25"
      Width="75"
      Canvas.Top="325"
      Canvas.Left="235"
      Click="buttonClick">Recognize</Button>
        <Button x:Name="btnClear" Content="Clear Canvas" Canvas.Left="10" Canvas.Top="367" Width="75" Click="btnClear_Click"/>
    </Canvas>
</Window>

Aggiungere un riferimento all'assembly Microsoft Ink Microsoft.Ink.dll, che può trovarsi in \Programmi\File comuni\Microsoft Shared\Ink. Sostituire il contenuto del file code-behind con il codice seguente.

using System.Windows;
using Microsoft.Ink;
using System.IO;

namespace InkRecognition
{
    /// <summary>
    /// Interaction logic for Window1.xaml
    /// </summary>

    public partial class Window1 : Window
    {

        public Window1()
        {
            InitializeComponent();
        }

        // Recognizes handwriting by using RecognizerContext
        private void buttonClick(object sender, RoutedEventArgs e)
        {
            using (MemoryStream ms = new MemoryStream())
            {
                theInkCanvas.Strokes.Save(ms);
                var myInkCollector = new InkCollector();
                var ink = new Ink();
                ink.Load(ms.ToArray());

                using (RecognizerContext context = new RecognizerContext())
                {
                    if (ink.Strokes.Count > 0)
                    {
                        context.Strokes = ink.Strokes;
                        RecognitionStatus status;

                        var result = context.Recognize(out status);

                        if (status == RecognitionStatus.NoError)
                            textBox1.Text = result.TopString;
                        else
                            MessageBox.Show("Recognition failed");
                    }
                    else
                    {
                        MessageBox.Show("No stroke detected");
                    }
                }
            }
        }

        private void btnClear_Click(object sender, RoutedEventArgs e) {
            theInkCanvas.Strokes.Clear();
        }
    }
}

Imports System.Windows
Imports Microsoft.Ink
Imports System.IO

'/ <summary>
'/ Interaction logic for Window1.xaml
'/ </summary>

Namespace InkRecognition

    Class Window1
        Inherits Window

        Public Sub New()
            InitializeComponent()
        End Sub


        ' Recognizes handwriting by using RecognizerContext
        Private Sub buttonClick(ByVal sender As Object, ByVal e As RoutedEventArgs)

            Using ms As New MemoryStream()
                theInkCanvas.Strokes.Save(ms)
                Dim myInkCollector As InkCollector = New InkCollector()
                Dim ink As Ink = New Ink()
                ink.Load(ms.ToArray())

                Using context As New RecognizerContext()
                    If ink.Strokes.Count > 0 Then
                        context.Strokes = ink.Strokes
                        Dim status As RecognitionStatus

                        Dim result As RecognitionResult = context.Recognize(status)

                        If status = RecognitionStatus.NoError Then
                            textBox1.Text = result.TopString
                        Else
                            MessageBox.Show("Recognition failed")
                        End If
                    Else
                        MessageBox.Show("No stroke detected")
                    End If
                End Using
            End Using
        End Sub

        Private Sub btnClear_Click(sender As Object, e As RoutedEventArgs)
            theInkCanvas.Strokes.Clear()
        End Sub
    End Class
End Namespace

Vedi anche

• Microsoft.Ink.InkCollector