墨迹分隔器示例

项目
06/13/2023

此示例基于 Ink 集合示例。它演示如何使用分隔器对象来分析墨迹输入。

有关分隔器的详细概念信息，请参阅分隔符对象。

更新窗体时，示例将围绕每个分析单元绘制一个边框，分为单词、线条、段落和绘图。除了使用不同的颜色外，这些矩形还按不同的量放大，以确保没有一个矩形被其他矩形遮盖。下表指定了每个分析单元的颜色和放大。

分析单位	Color	像素放大
Word	绿色	1
折线图	洋红色	3
Paragraph	蓝色	5
绘图	Red	1

设置窗体

加载窗体时，将创建一个 Divider 对象。创建 InkOverlay 对象并将其与窗体上的面板相关联。然后，事件处理程序将附加到 InkOverlay 对象，以跟踪何时添加和删除笔划。然后，如果识别器可用，则会将默认识别器的 RecognizerContext 对象分配给分隔器。然后设置分隔符对象的 LineHeight 属性，并将 InkOverlay 对象的 Strokes 集合分配给除法器。最后，启用 InkOverlay 对象。

// Create the ink overlay and associate it with the form
myInkOverlay = new Microsoft.Ink.InkOverlay(DrawArea.Handle);

// Set the erasing mode to stroke erase.
myInkOverlay.EraserMode = InkOverlayEraserMode.StrokeErase;

// Hook event handler for the Stroke event to myInkOverlay_Stroke.
// This is necessary since the application needs to pass the strokes 
// to the ink divider.
myInkOverlay.Stroke += new InkCollectorStrokeEventHandler(myInkOverlay_Stroke); 

// Hook the event handler for StrokeDeleting event to myInkOverlay_StrokeDeleting.
// This is necessary as the application needs to remove the strokes from 
// ink divider object as well.
myInkOverlay.StrokesDeleting += new InkOverlayStrokesDeletingEventHandler(myInkOverlay_StrokeDeleting);

// Hook the event handler for StrokeDeleted event to myInkOverlay_StrokeDeleted.
// This is necessary to update the layout analysis result when automatic layout analysis
// option is selected.
myInkOverlay.StrokesDeleted += new InkOverlayStrokesDeletedEventHandler(myInkOverlay_StrokeDeleted);

// Create the ink divider object
myInkDivider = new Divider();

// Add a default recognizer context to the divider object
// without adding the recognizer context, the divider would
// not use a recognizer to do its word segmentation and would
// have less accurate results.
// Adding the recognizer context slows down the call to 
// myInkDivider.Divide though.
// It is possible that there is no recognizer installed on the
// machine for this language. In that case the divider does
// not use a recognizer to improve its accuracy.
// Get the default recognizer if any
try
{
    Recognizers recognizers = new Recognizers();
     myInkDivider.RecognizerContext = recognizers.GetDefaultRecognizer().CreateRecognizerContext();
}
catch (InvalidOperationException)
{
     //We are in the case where no default recognizers can be found
}

    // The LineHeight property helps the InkDivider distinguish between 
    // drawing and handwriting. The value should be the expected height 
    // of the user's handwriting in ink space units (0.01mm).
    // Here we set the LineHeight to 840, which is about 1/3 of an inch.
    myInkDivider.LineHeight = 840;

// Assign ink overlay's strokes collection to the ink divider
// This strokes collection is updated in the event handler
myInkDivider.Strokes = myInkOverlay.Ink.Strokes;

// Enable ink collection
myInkOverlay.Enabled = true;

(通过 InkOverlay 对象的 Ink 属性) 访问，必须将 Divider 对象的 Strokes 集合与 InkOverlay 对象的 Strokes 集合保持同步。为确保发生这种情况，InkOverlay 对象的 Stroke 事件处理程序编写如下。请注意，事件处理程序首先测试是否将 EditingMode 设置为 Ink 以筛选掉橡皮擦笔划。如果用户已请求自动布局分析，则应用程序会调用窗体的 DivideInk 方法并刷新绘图区域。

private void myInkOverlay_Stroke(object sender, InkCollectorStrokeEventArgs e )
{
    // Filter out the eraser stroke.
    if(InkOverlayEditingMode.Ink == myInkOverlay.EditingMode)
    {
        // Add the new stroke to the ink divider's strokes collection
        myInkDivider.Strokes.Add(e.Stroke);
        
        if(miAutomaticLayoutAnalysis.Checked)
        {
            // Call DivideInk
            DivideInk();

            // Repaint the screen to reflect the change
            DrawArea.Refresh();
        }
    }
}

划分墨迹

当用户单击“文件”菜单上的“除法”时，将在 Divideer 对象上调用 Divide 方法。使用默认识别器（如果可用）。

DivisionResult divResult = myInkDivider.Divide();

变量引用divResult的生成的 DivisionResult 对象将传递给实用工具函数 getUnitBBBoxes()。实用工具函数返回请求的任何除法类型的矩形数组：段、线条、段落或绘图。

myWordBoundingBoxes = getUnitBBoxes(divResult, InkDivisionType.Segment, 1);
myLineBoundingBoxes = getUnitBBoxes(divResult, InkDivisionType.Line, 3);
myParagraphBoundingBoxes = getUnitBBoxes(divResult, InkDivisionType.Paragraph, 5);
myDrawingBoundingBoxes = getUnitBBoxes(divResult, InkDivisionType.Drawing, 1);

最后，强制重绘窗体面板，以便显示边框。

DrawArea.Refresh();

墨迹分析结果

在实用工具函数中，根据调用方请求的除法类型，使用 ResultByType 方法查询 DivisionResult 对象的结果。 ResultByType 方法返回一个 DivisionUnits 集合。集合中的每个 DivisionUnit 都表示一个绘图、单个手写识别段、一行手写或一个手写块，具体取决于调用实用工具函数时指定的内容。

DivisionUnits units = divResult.ResultByType(divType);

如果至少有一个 DivisionUnit，则会创建包含每个单元一个边界矩形的矩形数组。 (矩形按每种类型的单位的不同量进行膨胀（保存在 inflate 变量中）以防止重叠。)

// If there is at least one unit, we construct the rectangles
if((null != units) && (0 < units.Count))
{
    // We need to convert rectangles from ink units to
    // pixel units. For that, we need Graphics object
    // to pass to InkRenderer.InkSpaceToPixel method
    using (Graphics g = DrawArea.CreateGraphics())
    {

    // InkSpace to Pixel Space conversion setup done here. 
    // Not shown for brevity.

        // Iterate through the collection of division units to obtain the bounding boxes
        foreach(DivisionUnit unit in units)
        {
            // Get the bounding box of the strokes of the division unit
            divRects[i] = unit.Strokes.GetBoundingBox();

            // Div unit rect Ink space to Pixel space conversion done here. 
            // Not shown for brevity.

            // Inflate the rectangle by inflate pixels in both directions
            divRects[i].Inflate(inflate, inflate);

            // Increment the index
            ++i;
        }

    } // Relinquish the Graphics object
}

重绘窗体

当在上面强制重绘时，以下代码将执行以在墨迹周围的窗体上绘制每个 DivisionUnit 的边界框。

private void DrawArea_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
        {
            // Create the Pen used to draw bounding boxes.
            // First set of bounding boxes drawn here are 
            // the bounding boxes of paragraphs.
            // These boxes are drawn with Blue pen.
            Pen penBox = new Pen(Color.Blue, 2);

            // First, draw the bounding boxes for Paragraphs
            if(null != myParagraphBoundingBoxes)
            {
                // Draw bounding boxes for Paragraphs
                e.Graphics.DrawRectangles(penBox, myParagraphBoundingBoxes);
            }

            // Next, draw the bounding boxes for Lines
            if(null != myLineBoundingBoxes)
            {
                // Color is Magenta pen
                penBox.Color = Color.Magenta;
                // Draw the bounding boxes for Lines
                e.Graphics.DrawRectangles(penBox, myLineBoundingBoxes);
            }
            
            // Then, draw the bounding boxes for Words
            if(null != myWordBoundingBoxes)
            {
                // Color is Green
                penBox.Color = Color.Green;
                // Draw bounding boxes for Words
                e.Graphics.DrawRectangles(penBox, myWordBoundingBoxes);
            }
            
            // Finally, draw the boxes for Drawings
            if(null != myDrawingBoundingBoxes)
            {
                // Color is Red pen
                penBox.Color = Color.Red;
                // Draw bounding boxes for Drawings
                e.Graphics.DrawRectangles(penBox, myDrawingBoundingBoxes);
            }
        }

关闭窗体

窗体的 Dispose 方法释放在示例中使用的 InkOverlay、 Divider、 RecognizerContext 对象和 Strokes 集合。

通过