InkCollectorCursorDownEventHandler Delegate

Article
10/19/2012

Represents the method that handles the CursorDown event of an InkCollector object.

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

Syntax

'Declaration
Public Delegate Sub InkCollectorCursorDownEventHandler ( _
    sender As Object, _
    e As InkCollectorCursorDownEventArgs _
)
'Usage
Dim instance As New InkCollectorCursorDownEventHandler(AddressOf HandlerMethod)

public delegate void InkCollectorCursorDownEventHandler(
    Object sender,
    InkCollectorCursorDownEventArgs e
)

public delegate void InkCollectorCursorDownEventHandler(
    Object^ sender, 
    InkCollectorCursorDownEventArgs^ e
)

JScript does not support delegates.

Parameters

sender
Type: System.Object

The source InkCollector object of this event.

e
Type: Microsoft.Ink.InkCollectorCursorDownEventArgs

The InkCollectorCursorDownEventArgs object that contains the event data.

Remarks

When you create an InkCollectorCursorDownEventHandler 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. For performance reasons, the default event interest is off but is turned on automatically in managed code if you add an event handler.

This event may have an adverse effect on ink performance if too much code is executed in the event handlers.

To improve real-time ink performance, hide the mouse cursor while inking. To do so, hide the mouse cursor in the MouseDown event handler, and show the mouse cursor in the MouseUp event handler.

Examples

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 Sub mInkObject_CursorDown(ByVal sender As Object, ByVal e As InkCollectorCursorDownEventArgs)
    ' 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)
End Sub

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 Sub mInkObject_Stroke1(ByVal sender As Object, ByVal e As InkCollectorStrokeEventArgs)
    ' 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))) Then 

        Dim startTime As DateTime = DirectCast(e.Stroke.ExtendedProperties(New Guid(STROKE_START_GUID)).Data, DateTime)
        Dim endTime As DateTime = DateTime.Now
        Dim span As TimeSpan = 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 
        Me.statusLabelStrokeTime.Text = span.TotalSeconds.ToString()
    End If 
End Sub

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();
    }
}

Platforms

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.

Version Information

.NET Framework

Supported in: 3.0

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