Stroke.ExtendedProperties Property

Article
12/12/2007

Gets the collection of application-defined data.

Namespace: Microsoft.Ink
Assembly: Microsoft.Ink (in microsoft.ink.dll)

Syntax

'Declaration
Public ReadOnly Property ExtendedProperties As ExtendedProperties
'Usage
Dim instance As Stroke
Dim value As ExtendedProperties

value = instance.ExtendedProperties

public ExtendedProperties ExtendedProperties { get; }

public:
property ExtendedProperties^ ExtendedProperties {
    ExtendedProperties^ get ();
}

/** @property */
public ExtendedProperties get_ExtendedProperties ()

public function get ExtendedProperties () : ExtendedProperties

Not applicable.

Property Value

The collection of application-defined data.

Remarks

Applications can use the ExtendedProperties property to access the custom data that is stored in the Stroke object. This custom data is automatically serialized with the object.

Example

This C# example stores a a time stamp for each Stroke object when the InkCollector object's Stroke event fires. For each stroke drawn on an InkCollector, theInkCollector, the example stores the time stamp in the Stroke object's ExtendedProperties property. When the user clicks a button, theButton, a list box, theListBox, is populated with a list of the time stamps of the strokes.

//...
using Microsoft.Ink;

namespace CS_StrokeEvent
{
    public class Form1 : System.Windows.Forms.Form
    {
        private System.Windows.Forms.ListBox theListBox;
        private System.Windows.Forms.Button theButton;

        //...

        // Add the following after Main() in the generated code.

        InkCollector theInkCollector;
        // This GUID constant will be used for our strokes'
        // timestamp extended property.
        Guid theTimeGuid = new Guid(10, 11, 12, 10, 0, 0, 0, 0, 0, 0, 0);

        private void Form1_Load(object sender, System.EventArgs e)
        {
         // Initialize the InkCollector with the form's
         // window handle, then enable it.
         theInkCollector = new InkCollector(Handle);
         theInkCollector.Enabled = true;
         // Add a handler for Stroke Events to record
         // an extended property with each one.
         theInkCollector.Stroke += new InkCollectorStrokeEventHandler(TheStrokeHandler);
        }

        public void TheStrokeHandler(object sender, InkCollectorStrokeEventArgs e)
        {
            // Write the current time into this stroke.
            // First get the time as a long.
            long theTime = DateTime.Now.ToFileTime();
            // Store the data under its own Guid key.
            e.Stroke.ExtendedProperties.Add(theTimeGuid, theTime);
        }

        private void PopulateList()
        {
            //Clear the list before repopulating it.
            theListBox.Items.Clear();
            // Query the InkCollector's Ink for its Strokes collection.
            Strokes theStrokes = theInkCollector.Ink.Strokes;
            foreach (Stroke theStroke in theStrokes)
            {
                // Test for the timestamp property on this stroke.
                if (theStroke.ExtendedProperties.DoesPropertyExist(theTimeGuid))
                {
                    // Get the raw data out of this stroke's extended
                    // properties list, using the previously defined
                    // Guid as a key to the required extended property.
                    long theLong = (long)theStroke.ExtendedProperties[theTimeGuid].Data;
                    // Then turn it (as a FileTime) into a time string.
                    string theTime = DateTime.FromFileTime(theLong).ToString();
                    // Add the string to the list box.
                    theListBox.Items.Add(theTime);
                }
            }
        }

        private void theButton_Click(object sender, System.EventArgs e)
        {
            PopulateList();
        }

        // Event handler for the form's closed event
        private void Form1_Closed(object sender, System.EventArgs e)
        {
            theInkCollector.Dispose();
            theInkCollector = null;
        }
    }
}

This Microsoft® Visual Basic® .NET example stores a a time stamp for each Stroke object when the InkCollector object's Stroke event fires. For each stroke drawn on an InkCollector, theInkCollector, the example stores the time stamp in the Stroke object's ExtendedProperties property. When the user clicks a button, theButton, a list box, theListBox, is populated with a list of the time stamps of the strokes.

Imports Microsoft.Ink
Public Class Form1
    Inherits System.Windows.Forms.Form

#Region " Windows Form Designer generated code "
'... This section is generated automatically.
#End Region

    Private theInkCollector As InkCollector
    ' This GUID constant will be used for the strokes'
    ' timestamp extended property.
    Public theTimeGuid As Guid = _
        New Guid(10, 11, 12, 10, 0, 0, 0, 0, 0, 0, 0)

    Private Sub Form1_Load(ByVal sender As System.Object, _
    ByVal e As System.EventArgs) Handles MyBase.Load
        'Add our InkCollector initialization and Stroke event handler.
        theInkCollector = New InkCollector(Handle)
        theInkCollector.Enabled = True
        AddHandler theInkCollector.Stroke, AddressOf theStrokeHandler
    End Sub

    Public Sub theStrokeHandler( _
    ByVal sender As Object, _
    ByVal e As InkCollectorStrokeEventArgs)
        ' Write the current time into this stroke.
        ' First, get the current time as a Long FileTime.
        Dim theTime As Long = DateTime.Now.ToFileTime()
        ' Then store this value using its own Guid
        ' as a unique retrieval key.
        e.Stroke.ExtendedProperties.Add(theTimeGuid, theTime)
    End Sub

    Public Sub PopulateList()
        ' Clear the list before repopulating it.
        theListBox.Items.Clear()
        ' Query the InkCollector's Ink for its Strokes collection.
        Dim theStrokes As Strokes = theInkCollector.Ink.Strokes
        Dim theStroke As Stroke
        For Each theStroke In theStrokes
            ' If the timestamp property exists in this stroke:
            If _
            theStroke.ExtendedProperties.DoesPropertyExist(theTimeGuid) _
            Then
                Dim theLong As Long
                Dim theTime As String
                ' Get the raw data out of this stroke's extended
                ' properties list, using the previously defined
                ' Guid as a key to the required extended property.
                theLong = theStroke.ExtendedProperties(theTimeGuid).Data
                ' Then turn that Long (as a FileTime) into a string.
                theTime = DateTime.FromFileTime(theLong).ToString()
                theListBox.Items.Add(theTime)
            End If
        Next
    End Sub

    Private Sub theButton_Click(ByVal sender As System.Object, _
    ByVal e As System.EventArgs) Handles theButton.Click
        PopulateList()
    End Sub

    'Event handler for the form's closed event
    Private Sub Form1_Closed(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Closed
        theInkCollector.Dispose()
        Set theInkCollector = Nothing
    End Sub
End Class

Platforms

Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

Version Information

.NET Framework

Supported in: 3.0

Share via