ContextNode - класс

Статья
12/17/2008

Обновлен: Ноябрь 2007

Represents a node in a tree of objects that are created as part of ink analysis.

Пространство имен: System.Windows.Ink
Сборка: IAWinFX (в IAWinFX.dll)

Синтаксис

'Декларация
Public Class ContextNode
'Применение
Dim instance As ContextNode

public class ContextNode

public ref class ContextNode

public class ContextNode

public class ContextNode

Заметки

After an InkAnalyzer performs an ink analysis, it presents the results as a tree of ContextNode objects. The [T:System.Windows.Ink.RootNode is located at the top of the tree]; the tree presents smaller and smaller collections of strokes further down the tree. These nodes can be groups of words (such as paragraphs or lines), analyzed ink (such as words or drawings), or a variety of other types. (See the ContextNodeType class for a full list.)

You can manually add nodes, such as AnalysisHintNode, ImageNode and TextWordNode objects, to the InkAnalyzer.

In cases of corrupt input, this method throws a ArgumentException exception.

Примеры

This example takes an InkAnalyzer named theInkAnalyzer, and uses its ContextNode tree to fill a [System.Windows.Controls.TreeView] named theTreeView. When a node belonging to a tree view is selected, its associated strokes are set to appear in red. The [System.Windows.FrameworkElement.Tag] property is used to map between tree nodes and the context nodes that they represent.

Private Sub BuildTree() 
    ' Remove the old nodes from the TreeView and add the current results.
    Me.theResultsTreeView.Items.Clear()

    Dim rootNode As New TreeViewItem()
    rootNode.Tag = Me.theInkAnalyzer.RootNode
    rootNode.Header = theInkAnalyzer.RootNode.ToString()

    Me.theResultsTreeView.Items.Add(rootNode)

    WalkTree(Me.theInkAnalyzer.RootNode, rootNode)

End Sub 'BuildTree


Private Shared Sub WalkTree(ByVal parentContextNode As ContextNode, ByVal parentTreeNode As TreeViewItem) 

    parentTreeNode.IsExpanded = True

    For Each theContextSubnode As ContextNode In parentContextNode.SubNodes
        Dim newTreeNode As New TreeViewItem()
        newTreeNode.Header = theContextSubnode.ToString()

        If TypeOf theContextSubnode Is InkWordNode Then
            newTreeNode.Header += ": " + CType(theContextSubnode, InkWordNode).GetRecognizedString()
        ElseIf TypeOf theContextSubnode Is InkDrawingNode Then
            newTreeNode.Header += ": " + CType(theContextSubnode, InkDrawingNode).GetShapeName()
        End If

        ' If the context node is confirmed, add a note to the
        ' tree view item.
        If (theContextSubnode.IsConfirmed(ConfirmationType.NodeTypeAndProperties)) Then

            newTreeNode.Header += " Confirmed."
        End If


        ' Add the context node as a tag of the tree view item and
        ' add the new tree view item to the parent node.
        newTreeNode.Tag = theContextSubnode
        parentTreeNode.Items.Add(newTreeNode)

        WalkTree(theContextSubnode, newTreeNode)
    Next theContextSubnode

End Sub 'WalkTree

Sub theResultsTreeView_SelectedItemChanged(ByVal sender As Object, _
                                           ByVal e As RoutedPropertyChangedEventArgs(Of Object))
    Dim selectedTreeViewItem As TreeViewItem = e.NewValue '

    If selectedTreeViewItem Is Nothing Then
        Return
    End If

    ' Get the context node
    Dim selectedNode As ContextNode = CType(selectedTreeViewItem.Tag, ContextNode)

    MarkNodeAsRed(selectedNode)

    timeStampLabel.Content = ""

    ' Show selected results
    If Not (selectedNode Is Nothing) Then
        If selectedNode.Type = ContextNodeType.WritingRegion Then
            Dim writingRegion As WritingRegionNode = CType(selectedNode, WritingRegionNode)
            selectedResultsTextBox.Text = writingRegion.GetRecognizedString()
        ElseIf selectedNode.Type = ContextNodeType.Paragraph Then
            Dim paragraph As ParagraphNode = CType(selectedNode, ParagraphNode)
            selectedResultsTextBox.Text = paragraph.GetRecognizedString()
        ElseIf selectedNode.Type = ContextNodeType.Line Then
            Dim line As LineNode = CType(selectedNode, LineNode)
            selectedResultsTextBox.Text = line.GetRecognizedString()
        ElseIf selectedNode.Type = ContextNodeType.InkWord Then
            Dim inkWord As InkWordNode = CType(selectedNode, InkWordNode)
            Dim parentNode As ContextNode = inkWord.ParentNode
            If TypeOf parentNode Is LineNode Then
                Dim parentLine As LineNode = CType(parentNode, LineNode)
                ' Put parent line's recognized string into the text box
                selectedResultsTextBox.Text = parentLine.GetRecognizedString()

                ' Select the text that corresponds to the ink word
                Dim subNodes As New ContextNodeCollection(theInkAnalyzer)
                subNodes.Add(inkWord)
                Dim start As Integer
                Dim length As Integer
                parentLine.GetTextRangeFromNodes(subNodes, start, length)
                If start >= 0 AndAlso length > 0 Then
                    selectedResultsTextBox.Select(start, length)
                End If
            End If
        ElseIf selectedNode.Type = ContextNodeType.InkDrawing Then
            Dim drawingNode As InkDrawingNode = CType(selectedNode, InkDrawingNode)
            selectedResultsTextBox.Text = drawingNode.GetShapeName()
        ElseIf selectedNode.Type = ContextNodeType.InkBullet Then
            Dim bulletNode As InkBulletNode = CType(selectedNode, InkBulletNode)
            selectedResultsTextBox.Text = bulletNode.GetRecognizedString()
        ElseIf selectedNode.Type = ContextNodeType.CustomRecognizer Then
            Dim customRecognizer As CustomRecognizerNode = CType(selectedNode, CustomRecognizerNode)
            selectedResultsTextBox.Text = customRecognizer.GetRecognizedString()
        ElseIf selectedNode.Type = ContextNodeType.Object Then
            Dim selectedObject As ObjectNode = CType(selectedNode, ObjectNode)
            selectedResultsTextBox.Text = selectedObject.GetRecognizedString()
        Else
            selectedResultsTextBox.Text = ""
        End If
        If TypeOf selectedNode Is InkWordNode Then
            Dim inkWord As InkWordNode = CType(selectedNode, InkWordNode)

            ' Show the time stamp
            If inkWord.ContainsPropertyData(Me.timeStampGuid) Then
                Dim timeStamp As DateTime = CType(inkWord.GetPropertyData(Me.timeStampGuid), DateTime)
                timeStampLabel.Content = timeStamp.ToShortTimeString()
            End If
            ' Snippet to demonstrate GetPropertyDataIds
            Dim propertyDataIds As Guid() = inkWord.GetPropertyDataIds()
            ' Snippets to demonstrate loading and saving
            Dim data As Byte() = inkWord.SavePropertiesData()
            If Not inkWord.LoadPropertiesData(data) Then
                MessageBox.Show("Cannot load property data")
            End If
        End If
    End If
    PopulateLinksList(selectedNode)
    Me.currentNode = selectedNode
End Sub

Private Sub PopulateLinksList(ByVal selectedNode As ContextNode)

    linksListBox.Items.Clear()

    If selectedNode Is Nothing Then
        Return
    End If

    Dim link As ContextLink
    For Each link In selectedNode.Links
        linksListBox.Items.Add(link.SourceNode.ToString() + ", " & _
                                    link.DestinationNode.ToString() & ": " & _
                                    link.LinkDirection.ToString())
    Next
End Sub

Sub MarkNodeAsRed(ByVal selectedNode As ContextNode)
    ' Set all node strokes to black, but this one to red
    Dim stroke As Stroke
    For Each stroke In Me.theInkCanvas.Strokes
        If Not (selectedNode Is Nothing) AndAlso selectedNode.Strokes.Contains(stroke) Then
            stroke.DrawingAttributes.Color = Colors.Red
        Else
            stroke.DrawingAttributes.Color = Me.theInkCanvas.DefaultDrawingAttributes.Color
        End If
    Next stroke

End Sub 'theResultsTreeView_SelectedItemChanged

private void BuildTree()
{
    // Remove the old nodes from the TreeView and add the current results.
    this.theResultsTreeView.Items.Clear();

    TreeViewItem rootNode = new TreeViewItem();
    rootNode.Tag = this.theInkAnalyzer.RootNode;
    rootNode.Header = theInkAnalyzer.RootNode.ToString();

    this.theResultsTreeView.Items.Add(rootNode);

    WalkTree(this.theInkAnalyzer.RootNode, rootNode);

}

private static void WalkTree(ContextNode parentContextNode, TreeViewItem parentTreeNode)
{
    // Expand the current TreeViewItem.
    parentTreeNode.IsExpanded = true;

    foreach (ContextNode theContextSubnode
        in parentContextNode.SubNodes)
    {
        TreeViewItem newTreeNode = new TreeViewItem();
        newTreeNode.Header = theContextSubnode.ToString();

        if (theContextSubnode is InkWordNode)
        {
            newTreeNode.Header += ": " +
                ((InkWordNode)theContextSubnode).GetRecognizedString();
        }
        else if (theContextSubnode is InkDrawingNode)
        {
            newTreeNode.Header += ": " +
                ((InkDrawingNode)theContextSubnode).GetShapeName();
        }

        // If the context node is confirmed, add a note to the
        // tree view item.
        if (theContextSubnode.IsConfirmed(ConfirmationType.NodeTypeAndProperties))
        {
            newTreeNode.Header += " Confirmed.";
        }

        // Add the context node as a tag of the tree view item and
        // add the new tree view item to the parent node.
        newTreeNode.Tag = theContextSubnode;
        parentTreeNode.Items.Add(newTreeNode);

        WalkTree(theContextSubnode, newTreeNode);
    }
}


void theResultsTreeView_SelectedItemChanged(object sender, RoutedPropertyChangedEventArgs<object> e)
{
    TreeViewItem selectedTreeViewItem = e.NewValue as TreeViewItem;

    if (selectedTreeViewItem == null)
    {
        return;
    }

    // Get the context node
    ContextNode selectedNode = (ContextNode)selectedTreeViewItem.Tag;

    MarkNodeAsRed(selectedNode);

    timeStampLabel.Content = "";

    // Show selected results
    if (selectedNode != null)
    {
        if (selectedNode.Type == ContextNodeType.WritingRegion)
        {
            WritingRegionNode writingRegion = (WritingRegionNode)selectedNode;
            selectedResultsTextBox.Text = writingRegion.GetRecognizedString();
        }
        else if (selectedNode.Type == ContextNodeType.Paragraph)
        {
            ParagraphNode paragraph = (ParagraphNode)selectedNode;
            selectedResultsTextBox.Text = paragraph.GetRecognizedString();
        }
        else if (selectedNode.Type == ContextNodeType.Line)
        {
            LineNode line = (LineNode)selectedNode;
            selectedResultsTextBox.Text = line.GetRecognizedString();
        }
        else if (selectedNode.Type == ContextNodeType.InkWord)
        {
            InkWordNode inkWord = (InkWordNode)selectedNode;
            ContextNode parentNode = inkWord.ParentNode;
            if (parentNode is LineNode)
            {
                LineNode parentLine = (LineNode)parentNode;
                // Put parent line's recognized string into the text box
                selectedResultsTextBox.Text = parentLine.GetRecognizedString();

                // Select the text that corresponds to the ink word
                ContextNodeCollection subNodes = new ContextNodeCollection(theInkAnalyzer);
                subNodes.Add(inkWord);
                int start;
                int length;
                parentLine.GetTextRangeFromNodes(subNodes, out start, out length);
                if (start >= 0 && length > 0)
                {
                    selectedResultsTextBox.Select(start, length);
                }
            }
        }
        else if (selectedNode.Type == ContextNodeType.InkDrawing)
        {
            InkDrawingNode drawingNode = (InkDrawingNode)selectedNode;
            selectedResultsTextBox.Text = drawingNode.GetShapeName();
        }
        else if (selectedNode.Type == ContextNodeType.InkBullet)
        {
            InkBulletNode bulletNode = (InkBulletNode)selectedNode;
            selectedResultsTextBox.Text = bulletNode.GetRecognizedString();
        }
        else if (selectedNode.Type == ContextNodeType.CustomRecognizer)
        {
            CustomRecognizerNode customRecognizer = (CustomRecognizerNode)selectedNode;
            selectedResultsTextBox.Text = customRecognizer.GetRecognizedString();
        }
        else if (selectedNode.Type == ContextNodeType.Object)
        {
            ObjectNode selectedObject = (ObjectNode)selectedNode;
            selectedResultsTextBox.Text = selectedObject.GetRecognizedString();
        }
        else
        {
            selectedResultsTextBox.Text = "";
        }

        if (selectedNode is InkWordNode)
        {
            InkWordNode inkWord = (InkWordNode)selectedNode;

            // Show the time stamp
            if (inkWord.ContainsPropertyData(this.timeStampGuid))
            {
                DateTime timeStamp =
                    (DateTime)inkWord.GetPropertyData(this.timeStampGuid);
                timeStampLabel.Content = timeStamp.ToShortTimeString();
            }

            // Snippet to demonstrate GetPropertyDataIds
            Guid[] propertyDataIds = inkWord.GetPropertyDataIds();
            // Snippets to demonstrate loading and saving
            byte[] data = inkWord.SavePropertiesData();
            if (!inkWord.LoadPropertiesData(data))
                MessageBox.Show("Cannot load property data");
        }

    }
    PopulateLinksList(selectedNode);
    this.currentNode = selectedNode;
}

private void PopulateLinksList(ContextNode selectedNode)
{
    linksListBox.Items.Clear();
    if (selectedNode == null)
    {
        return;
    }

    foreach (ContextLink link in selectedNode.Links)
    {
        linksListBox.Items.Add(link.SourceNode.ToString() + ", " +
                                    link.DestinationNode.ToString() + ": " +
                                    link.LinkDirection.ToString());
    }
}

private void MarkNodeAsRed(ContextNode selectedNode)
{
    // Set all node strokes to black, but this one to red
    foreach (Stroke stroke in this.theInkCanvas.Strokes)
    {
        if (selectedNode != null &&
            selectedNode.Strokes.Contains(stroke))
            stroke.DrawingAttributes.Color = Colors.Red;
        else
            stroke.DrawingAttributes.Color = 
                this.theInkCanvas.DefaultDrawingAttributes.Color;
    }
}

Иерархия наследования

Потокобезопасность

Любые открытые члены этого типа, объявленные как static (Shared в Visual Basic), являются потокобезопасными. Потокобезопасность членов экземпляров не гарантируется.

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.