InkCollectorNewPacketsEventHandler Delegate
Represents the method that handles the NewPackets event of an InkCollector object.
Namespace: Microsoft.Ink
Assembly: Microsoft.Ink (in Microsoft.Ink.dll)
Syntax
'Declaration
Public Delegate Sub InkCollectorNewPacketsEventHandler ( _
sender As Object, _
e As InkCollectorNewPacketsEventArgs _
)
'Usage
Dim instance As New InkCollectorNewPacketsEventHandler(AddressOf HandlerMethod)
public delegate void InkCollectorNewPacketsEventHandler(
Object sender,
InkCollectorNewPacketsEventArgs e
)
public delegate void InkCollectorNewPacketsEventHandler(
Object^ sender,
InkCollectorNewPacketsEventArgs^ e
)
JScript does not support delegates.
Parameters
sender
Type: System.ObjectThe source InkCollector object of this event.
e
Type: Microsoft.Ink.InkCollectorNewPacketsEventArgsThe InkCollectorNewPacketsEventArgs object that contains the event data.
Remarks
When you create an InkCollectorNewPacketsEventHandler 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.
Packets are received while a stroke is being collected. Packet events occur rapidly, and a NewPackets event handler must be fast or ink performance suffers.
Examples
This example demonstrates how you can subscribe to the CursorInRange event, and the NewPackets event obtain ink pressure data, and use that information to manipulate an DrawingAttributes object.
When the CursorInRange event fires, a check is made to see if this is the first time that the InkCollector object has come in contact with this particular Cursor object. If so, the DrawingAttributes property is assigned with a clone of the DefaultDrawingAttributes property. This ensures that subsequent access to the DrawingAttributes property does not throw a null reference exception.
Private Sub mInkObject_CursorInRange(ByVal sender As Object, ByVal e As InkCollectorCursorInRangeEventArgs)
Const MOUSE_CURSOR_ID As Integer = 1
If e.NewCursor Then
' mInkObject can be InkCollector, InkOverlay, or InkPicture
e.Cursor.DrawingAttributes = mInkObject.DefaultDrawingAttributes.Clone()
' if this cursor is the mouse, we'll set color to red
If (MOUSE_CURSOR_ID = e.Cursor.Id) Then
e.Cursor.DrawingAttributes.Color = Color.Red
End If
End If
End Sub
private void mInkObject_CursorInRange(object sender, InkCollectorCursorInRangeEventArgs e)
{
const int MOUSE_CURSOR_ID = 1;
if (e.NewCursor)
{
// mInkObject can be InkCollector, InkOverlay, or InkPicture
e.Cursor.DrawingAttributes = mInkObject.DefaultDrawingAttributes.Clone();
// if this cursor is the mouse, we'll set color to red
if (MOUSE_CURSOR_ID == e.Cursor.Id)
{
e.Cursor.DrawingAttributes.Color = Color.Red;
}
}
}
When the NewPackets event fires, a check is made to see if NormalPressure is included in the packet data. If so, pressure information is displayed on a status label, and the DrawingAttributes property is modified.
Private Sub mInkObject_NewPackets(ByVal sender As Object, ByVal e As InkCollectorNewPacketsEventArgs)
' find the NormalPressure PacketProperty
' Set NormalPressure to -1 if not there, as some digitizers won't support it
Dim PacketDesc As Guid() = e.Stroke.PacketDescription
Dim NormalPressure As Integer = -1
For k As Integer = 0 To PacketDesc.Length - 1
If PacketDesc(k) = PacketProperty.NormalPressure Then
' for simplicity, in case of multiple packets, use the first packet only
NormalPressure = e.PacketData(k)
End If
Next k
' If we have the NormalPressure information
' change DrawingAttributes according to the NormalPressure
' Note that the change does not take effect until the next stroke
If NormalPressure <> -1 Then
' display the pressure on a status label
Me.statusLabelPressure.Text = NormalPressure.ToString()
e.Cursor.DrawingAttributes.Width = NormalPressure * 4
' if pressure is above 127, change color to Red
If NormalPressure > 127 Then
e.Cursor.DrawingAttributes.Color = Color.Red
Else
e.Cursor.DrawingAttributes.Color = mInkObject.DefaultDrawingAttributes.Color
End If
End If
End Sub
private void mInkObject_NewPackets(object sender, InkCollectorNewPacketsEventArgs e)
{
// find the NormalPressure PacketProperty
// Set NormalPressure to -1 if not there, as some digitizers won't support it
Guid[] PacketDesc = e.Stroke.PacketDescription;
int NormalPressure = -1;
for (int k = 0; k < PacketDesc.Length; k++)
{
if (PacketDesc[k] == PacketProperty.NormalPressure)
{
// for simplicity, in case of multiple packets, use the first packet only
NormalPressure = e.PacketData[k];
}
}
// If we have the NormalPressure information
// change DrawingAttributes according to the NormalPressure
// Note that the change does not take effect until the next stroke
if (NormalPressure != -1)
{
// display the pressure on a status label
this.statusLabelPressure.Text = NormalPressure.ToString();
e.Cursor.DrawingAttributes.Width = NormalPressure * 4;
// if pressure is above 127, change color to Red
if (NormalPressure > 127)
{
e.Cursor.DrawingAttributes.Color = Color.Red;
}
else
{
e.Cursor.DrawingAttributes.Color = mInkObject.DefaultDrawingAttributes.Color;
}
}
}
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