RecognitionAlternate.Midline 属性

项目
10/28/2008

获取表示单行文本的 RecognitionAlternate 对象的中线。

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

语法

声明
Public ReadOnly Property Midline As Line
用法
Dim instance As RecognitionAlternate
Dim value As Line

value = instance.Midline

public Line Midline { get; }

public:
property Line Midline {
    Line get ();
}

/** @property */
public Line get_Midline()

public function get Midline () : Line

属性值

类型：Microsoft.Ink.Line
表示单行文本的 RecognitionAlternate 对象的中线。

备注

中线是用于对齐每个字符（上行字母 除外）主体顶部的假想水平线。中线也与 x 的顶部等高。

备注

如果识别备选项 跨一行文本中的多个识别段，则此属性返回一条与备选项基线平行的线。基线与中线之间的距离由第一个段中的相应距离确定。

使用 AlternatesWithConstantPropertyValues 方法，并将 g 参数设置为 RecognitionProperty.Segmentation 全局唯一标识符 (GUID)，可以获取与原始备选项分段对应的由单段识别备选项组成的集合。

备注

如果识别备选项跨多行，则此属性会引发 COMException 异常。使用 LineAlternates 属性可以获取对应于多行识别备选项的单行识别备选项的集合。

示例

此 C# 示例定义窗体 RecognitionResultForm 的事件处理程序，该窗体中已添加了 ListBox 控件 theListBox 和两个 Button 控件（theRecognizeButton 和 theGetDataButton）。此示例还定义一个 InkCollector (theInkCollector)、一个 RecognizerContext (theRecognizerContext) 和一个 RecognitionResult (theRecognitionResult)，用于收集墨迹和执行识别。

theRecognizeButton 的单击事件的事件处理程序对墨迹收集器中的笔画执行识别，并将识别结果的最佳备选项的有关信息放置到 theListBox 中。

theGetDataButton 的单击事件的事件处理程序获取最佳备选项的行备选项集合。然后，该处理程序绘制每个行备选项的上行字母 线、中线、基线和下行字母 线。该处理程序还将每个行备选项的行号和置信级别的有关信息放置到 theListBox 中。

[C#]

// Declare ink elements and create pens.
Microsoft.Ink.InkCollector theInkCollector;
Microsoft.Ink.RecognizerContext theRecognizerContext;
Microsoft.Ink.RecognitionResult theRecognitionResult;

System.Drawing.Pen thePen1 = new Pen(Color.Red);
System.Drawing.Pen thePen2 = new Pen(Color.Orange);
System.Drawing.Pen thePen3 = new Pen(Color.Yellow);
System.Drawing.Pen thePen4 = new Pen(Color.Green);

// Event handler for the form's Load event.
private void RecognitionResultForm_Load(object sender, System.EventArgs e)
{
    // Create the ink collector.
    this.theInkCollector = new Microsoft.Ink.InkCollector(this.Handle);
    this.theInkCollector.Enabled = true;

    // Create the default recognizer context.
    this.theRecognizerContext = new Microsoft.Ink.RecognizerContext();
}

// Event handler for the "Recognize" button's Click event.
private void theRecognizeButton_Click(object sender, System.EventArgs e)
{
    // Check for ink before performing recognition.
    this.theListBox.Items.Clear();
    if (0 == this.theInkCollector.Ink.Strokes.Count)
    {
        this.theListBox.Items.Add("No ink to recognize.");
        return;
    }

    // Perform recognition on the strokes currently in the ink collector.
    Microsoft.Ink.RecognitionStatus theRecognitionStatus;
    this.theRecognizerContext.Strokes = this.theInkCollector.Ink.Strokes;
    this.theRecognitionResult =
        this.theRecognizerContext.Recognize(out theRecognitionStatus);

    // Display information about the recognition result in the list box.
    this.theListBox.Items.Add("The top alternate is: " +
        this.theRecognitionResult.TopString);
    this.theListBox.Items.Add("The top confidence is: " +
        this.theRecognitionResult.TopConfidence);
    this.theListBox.Items.Add("The number of strokes is:" +
        this.theRecognitionResult.Strokes.Count);
}

// Event handler for the "Get Data" button's Click event.
private void theGetDataButton_Click(object sender, System.EventArgs e)
{
    // Refresh the list box and check for a recognition result.
    this.theListBox.Items.Clear();
    if (null == this.theRecognitionResult)
    {
        this.theListBox.Items.Add("No recognition result available.");
        return;
    }

    // Get the line alternates collection for the top alternate.
    Microsoft.Ink.RecognitionAlternates theLineAlternates =
        this.theRecognitionResult.TopAlternate.LineAlternates;

    using (System.Drawing.Graphics g = this.CreateGraphics())
    {
        // Clear the drawing surface
        g.Clear(this.BackColor);

        // For each line alternate in the collection:
        foreach(Microsoft.Ink.RecognitionAlternate theAlternate
                    in theLineAlternates)
        {
            // Add information about the alternate to the list box.
            this.theListBox.Items.Add("The Line Number is: " +
                theAlternate.LineNumber.ToString());
            this.theListBox.Items.Add("The alternate's text is: " +
                theAlternate.ToString());
            this.theListBox.Items.Add("The number of strokes is: " +
                theAlternate.Strokes.Count);
            this.theListBox.Items.Add("The Confidence is: " +
                theAlternate.Confidence.ToString());

            // Draw the ascender, midline, baseline, and descender.
            DrawLine(g, theAlternate.Ascender, this.thePen1);
            DrawLine(g, theAlternate.Midline, this.thePen2);
            DrawLine(g, theAlternate.Baseline, this.thePen3);
            DrawLine(g, theAlternate.Descender, this.thePen4);

            this.theListBox.Items.Add(string.Empty);
        }

        // Redraw the ink.
        this.theInkCollector.Renderer.Draw(g, this.theRecognitionResult.Strokes);
    }
}

// Event handler for the form's Closed event.
private void RecognitionResultForm_Closed(object sender, System.EventArgs e)
{
    // Free the resources for the ink collector, recognizer context, and pens.
    this.theInkCollector.Dispose();
    this.theInkCollector = null;
    this.theRecognizerContext.Dispose();
    this.theRecognizerContext = null;

    this.thePen1.Dispose();
    this.thePen1 = null;
    this.thePen2.Dispose();
    this.thePen2 = null;
    this.thePen3.Dispose();
    this.thePen3 = null;
    this.thePen4.Dispose();
    this.thePen4 = null;
}

// Helper function to draw the lines.
private void DrawLine(System.Drawing.Graphics g,
    Microsoft.Ink.Line line, System.Drawing.Pen pen)
{
    System.Drawing.Point point1 = line.BeginPoint;
    System.Drawing.Point point2 = line.EndPoint;

    this.theInkCollector.Renderer.InkSpaceToPixel(g, ref point1);
    this.theInkCollector.Renderer.InkSpaceToPixel(g, ref point2);

    g.DrawLine(pen, point1, point2);
}

此 Microsoft(R) Visual Basic(R) .NET 示例定义窗体 RecognitionResultForm 的事件处理程序，该窗体中已添加了 ListBox 控件 theListBox 和两个 Button 控件（theRecognizeButton 和 theGetDataButton）。此示例还定义一个 InkCollector (theInkCollector)、一个 RecognizerContext (theRecognizerContext) 和一个 RecognitionResult (theRecognitionResult)，用于收集墨迹和执行识别。

theRecognizeButton 的单击事件的事件处理程序对墨迹收集器中的笔画执行识别，并将识别结果的最佳备选项的有关信息放置到 theListBox 中。

[Visual Basic]

    Dim theInkCollector As Microsoft.Ink.InkCollector
    Dim theRecognizerContext As Microsoft.Ink.RecognizerContext
    Dim theRecognitionResult As Microsoft.Ink.RecognitionResult

    Dim thePen1 As System.Drawing.Pen = New Pen(Color.Red)
    Dim thePen2 As System.Drawing.Pen = New Pen(Color.Orange)
    Dim thePen3 As System.Drawing.Pen = New Pen(Color.Yellow)
    Dim thePen4 As System.Drawing.Pen = New Pen(Color.Green)

    ' Event handler for the form's Load event.
    Private Sub RecognitionResultForm_Load(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles MyBase.Load

        ' Create the ink collector.
        Me.theInkCollector = New Microsoft.Ink.InkCollector(Me.Handle)
        Me.theInkCollector.Enabled = True

        ' Create the default recognizer context.
        Me.theRecognizerContext = New Microsoft.Ink.RecognizerContext
    End Sub

    ' Event handler for the "Recognize" button's Click event.
    Private Sub theRecognizeButton_Click(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles theRecognizeButton.Click

        ' Check for ink before performing recognition.
        Me.theListBox.Items.Clear()
        If Me.theInkCollector.Ink.Strokes.Count = 0 Then
            Me.theListBox.Items.Add("No ink to recognize.")
            Return
        End If

        ' Perform recognition on the strokes currently in the ink collector.
        Dim theRecognitionStatus As Microsoft.Ink.RecognitionStatus
        Me.theRecognizerContext.Strokes = Me.theInkCollector.Ink.Strokes
        Me.theRecognitionResult = _
            Me.theRecognizerContext.Recognize(theRecognitionStatus)

        ' Display information about the recognition result in the list box.
        Me.theListBox.Items.Add("The top alternate is: " & _
                                    theRecognitionResult.TopString)
        Me.theListBox.Items.Add("The top confidence is: " & _
                                    theRecognitionResult.TopConfidence.ToString())
        Me.theListBox.Items.Add("The number of strokes is:" & _
                                    theRecognitionResult.Strokes.Count)
    End Sub

    ' Event handler for the "Get Data" button's Click event.
    Private Sub theGetDataButton_Click(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles theGetDataButton.Click

        ' Refresh the list box and check for a recognition result.
        Me.theListBox.Items.Clear()
        If (Me.theRecognitionResult Is Nothing) Then
            Me.theListBox.Items.Add("No recognition result available.")
            Return
        End If

        ' Get the line alternates collection for the top alternate.
        Dim theLineAlternates As Microsoft.Ink.RecognitionAlternates = _
            Me.theRecognitionResult.TopAlternate.LineAlternates()

        ' Create a temporary graphics object.
        Dim g As System.Drawing.Graphics = Me.CreateGraphics()

        ' Clear the drawing surface
        g.Clear(Me.BackColor)

        ' For each line alternate in the collection:
        For Each theAlternate As Microsoft.Ink.RecognitionAlternate _
                    In theLineAlternates

            ' Add information about the alternate to the list box.
            Me.theListBox.Items.Add("The Line Number is: " & _
                theAlternate.LineNumber.ToString())
            Me.theListBox.Items.Add("The alternate's text is: " & _
                theAlternate.ToString())
            Me.theListBox.Items.Add("The number of strokes is: " & _
                theAlternate.Strokes.Count)
            Me.theListBox.Items.Add("The Confidence is: " & _
                theAlternate.Confidence.ToString())

            ' Draw the ascender, midline, baseline, and descender.
            DrawLine(g, theAlternate.Ascender, Me.thePen1)
            DrawLine(g, theAlternate.Midline, Me.thePen2)
            DrawLine(g, theAlternate.Baseline, Me.thePen3)
            DrawLine(g, theAlternate.Descender, Me.thePen4)

            Me.theListBox.Items.Add(String.Empty)
        Next

        ' Redraw the ink.
        Me.theInkCollector.Renderer.Draw(g, Me.theRecognitionResult.Strokes)

        ' Dispose of the graphics object.
        g.Dispose()
    End Sub

    ' Event handler for the form's Closed event.
    Private Sub RecognitionResultForm_Closed(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles MyBase.Closed

        ' Free the resources for the ink collector and recognizer context.
        Me.theInkCollector.Dispose()
        Me.theInkCollector = Nothing
        Me.theRecognizerContext.Dispose()
        Me.theRecognizerContext = Nothing

        Me.thePen1.Dispose()
        Me.thePen1 = Nothing
        Me.thePen2.Dispose()
        Me.thePen2 = Nothing
        Me.thePen3.Dispose()
        Me.thePen3 = Nothing
        Me.thePen4.Dispose()
        Me.thePen4 = Nothing
    End Sub

    ' Helper function to draw the lines.
    Private Sub DrawLine(ByVal g As System.Drawing.Graphics, _
        ByVal line As Microsoft.Ink.Line, ByVal pen As System.Drawing.Pen)

        Dim point1 As System.Drawing.Point = line.BeginPoint
        Dim point2 As System.Drawing.Point = line.EndPoint

        Me.theInkCollector.Renderer.InkSpaceToPixel(g, point1)
        Me.theInkCollector.Renderer.InkSpaceToPixel(g, point2)

        g.DrawLine(pen, point1, point2)
    End Sub