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InkCollector.Stroke Event

Occurs when the user finishes drawing a new stroke on any tablet.

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

public event InkCollectorStrokeEventHandler Stroke

The event handler receives an argument of type InkCollectorStrokeEventArgs that contains data about this event.

When you create an InkCollectorStrokeEventHandler delegate, you identify the method that handles the event. To associate the event with your event handler, add an instance of the delegate to the event. The event handler is called whenever the event occurs, unless you remove the delegate. The default event interest is on.

The Stroke event is fired when in select or erase mode, not only when inserting ink. This requires that you monitor the editing mode (which you are responsible for setting) and be aware of the mode before interpreting the event. The advantage of this requirement is greater freedom to innovate on the platform through greater awareness of platform events.

NoteNote:

The Stroke event fires when the user finishes drawing a stroke, not when a stroke is added to the Strokes collection. When the user first starts to draw a stroke, it is added immediately to the Strokes collection; however, the Stroke event does not fire until the stroke is complete. Therefore, a Stroke object may exist in the Strokes collection before the Stroke event handler fires for that Stroke object.

This example demonstrates how you can subscribe to the CursorDown event, and the Stroke event to calculate the length of time it takes the user to create a stroke.

At the beginning of a stroke, the CursorDown event fires. The current time is placed into the ExtendedProperties collection of the Stroke object.

private void mInkObject_CursorDown(object sender, InkCollectorCursorDownEventArgs e)
{
    // add extended property indicating the time the stroke started 
    // STROKE_START_GUID is class level string via GUID generator
    e.Stroke.ExtendedProperties.Add(new Guid(STROKE_START_GUID), DateTime.Now);
}

When the stroke is complete, the Stroke event fires. The start time is retrieved from the ExtendedProperties collection of the Stroke object, and used to calculate the elapsed time.

private void mInkObject_Stroke1(object sender, InkCollectorStrokeEventArgs e)
{
    // check to see if extended property for start time exists 
    // Attempting to access an extended property that hasn't been created throws an exception 
    // STROKE_START_GUID is class level string via GUID generator 
    if (e.Stroke.ExtendedProperties.DoesPropertyExist(new Guid(STROKE_START_GUID)))
    {
        DateTime startTime = (DateTime)e.Stroke.ExtendedProperties[new Guid(STROKE_START_GUID)].Data;
        DateTime endTime = DateTime.Now;
        TimeSpan span = new TimeSpan(endTime.Ticks - startTime.Ticks);

        // add extended property indicating the time the stroke ended 
        // STROKE_END_GUID is class level string via GUID generator
        e.Stroke.ExtendedProperties.Add(new Guid(STROKE_END_GUID), endTime);

        // display the number of seconds in creating this stroke 
        this.statusLabelStrokeTime.Text = span.TotalSeconds.ToString();
    }
}

In this example, the event handler for the Stroke event creates a shadow stroke by creating a new Stroke object based upon the current Stroke object, and then changing the color and position of the newly created Stroke object.

private void mInkObject_Stroke2(object sender, InkCollectorStrokeEventArgs e)
{
    this.mNumStroke++;
    statusLabelStrokeCount.Text = this.mNumStroke.ToString();

    // Add a new stroke created from the stroke points of the current stroke
    Stroke StrokeShadow = e.Stroke.Ink.CreateStroke(e.Stroke.GetPoints());

    // clone the DrawingAttributes and set color to Gray
    StrokeShadow.DrawingAttributes = e.Stroke.DrawingAttributes.Clone();
    StrokeShadow.DrawingAttributes.Color = Color.Gray;

    // use MaskPen to keep the shadow stroke in the background
    StrokeShadow.DrawingAttributes.RasterOperation = RasterOperation.MaskPen;

    // offset the shadow stroke
    StrokeShadow.Move(200, 200);

    // redraw the ink canvas
    panelInkCanvas.Invalidate();

}

Windows 7, Windows Vista, Windows Server 2008 R2, Windows Server 2008

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.0

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