InkOverlay.NewInAirPackets Event
Occurs when the InkOverlay object detects an in-air packet.
Namespace: Microsoft.Ink
Assembly: Microsoft.Ink (in Microsoft.Ink.dll)
Syntax
'Declaration
Public Event NewInAirPackets As InkCollectorNewInAirPacketsEventHandler
'Usage
Dim instance As InkOverlay
Dim handler As InkCollectorNewInAirPacketsEventHandler
AddHandler instance.NewInAirPackets, handler
public event InkCollectorNewInAirPacketsEventHandler NewInAirPackets
public:
event InkCollectorNewInAirPacketsEventHandler^ NewInAirPackets {
void add (InkCollectorNewInAirPacketsEventHandler^ value);
void remove (InkCollectorNewInAirPacketsEventHandler^ value);
}
JScript does not support events.
Remarks
This event occurs when a user moves a cursor within the physical detection range (proximity) of the tablet context while the cursor is within the InkOverlay object's window or the user moves a mouse within the InkOverlay object's associated window.
NewInAirPackets events are generated rapidly, and the event handler must be fast or performance suffers.
The event handler receives an argument of type InkCollectorNewInAirPacketsEventArgs containing data about this event.
When you create an InkCollectorNewInAirPacketsEventHandler 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 if you add an event handler.
The NewInAirPackets event fires even 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.
Examples
This C# example draws a rectangle on the form with a bold outline when the in-air packets are within the rectangle or with a narrow outline when the packets are outside the rectangle. This demonstrates how to use the packet events to control application behaviors.
using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
using Microsoft.Ink;
namespace CSInAirPacketEvents
{
public class Form1 : System.Windows.Forms.Form
{
//...
InkOverlay theInkOverlay;
int indexX, indexY;
Rectangle rectInterest;
bool thickBorder;
public Form1()
{
//...
//Initialize the InkOverlay object.
theInkOverlay= new InkOverlay(Handle);
theInkOverlay.Enabled = true;
//Initialize the target rectangle
rectInterest = new Rectangle(40, 40, 200, 80);
thickBorder = false;
//Save the X and Y data locations within the packet data.
GetXYIndexes(ref indexX, ref indexY);
//Add the event handler for in-air packets
theInkOverlay.NewInAirPackets += new InkCollectorNewInAirPacketsEventHandler(NewInAirPackets_Event);
}
//...
private void GetXYIndexes(ref int theXIndex, ref int theYIndex)
{
// Get the indexes of the X and Y data within the raw
// packet data array.
Guid [] theGuids = theInkOverlay.DesiredPacketDescription;
for (int i = 0; i < theGuids.Length; i++)
{
if (theGuids[i].Equals(PacketProperty.X))
theXIndex = i;
if (theGuids[i].Equals(PacketProperty.Y))
theYIndex = i;
}
}
private void NewInAirPackets_Event(object sender, InkCollectorNewInAirPacketsEventArgs e)
{
Graphics g = this.CreateGraphics();
Point [] pt = new Point [1];
pt[0].X = e.PacketData[indexX];
pt[0].Y = e.PacketData[indexY];
theInkOverlay.Renderer.InkSpaceToPixel(g, ref pt);
// The event may return with data for multiple packets.
// To simplify things, we'll only look at the first.
if (rectInterest.Contains(pt[0].X, pt[0].Y))
{
if (!thickBorder)
{
thickBorder = true;
Refresh();
}
}
else
{
if (thickBorder)
{
thickBorder = false;
Refresh();
}
}
}
private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
{
Graphics g = e.Graphics;
Pen thePen = new Pen(Color.Black, 2);
if (thickBorder)
thePen.Width = 5;
g.DrawRectangle(thePen, rectInterest);
}
// Event handler for the form's closed event
private void Form1_Closed(object sender, System.EventArgs e)
{
theInkOverlay.Dispose();
theInkOverlay= null;
}
}
}
This Microsoft Visual Basic .NET example draws a rectangle on the form with a bold outline when the in-air packets are within the rectangle or with a narrow outline when the packets are outside the rectangle. This demonstrates how to use the packet events to control application behaviors.
Imports Microsoft.Ink
Public Class Form1
Inherits System.Windows.Forms.Form
Dim theInkOverlay As InkOverlay
Dim indexX, indexY As Integer
Dim rectInterest As Rectangle
Dim thickBorder As Boolean
'...
Public Sub New()
MyBase.New()
'This call is required by the Windows Form Designer.
InitializeComponent()
'Initialize the InkOverlay object.
theInkOverlay = New InkOverlay(Handle)
theInkOverlay.Enabled = True
'Initialize the target rectangle
rectInterest = New Rectangle(40, 40, 200, 80)
thickBorder = False
'Save the X and Y data locations within the packet data.
GetXYIndexes(indexX, indexY)
'Add the event handler for in air packets
AddHandler theInkOverlay.NewInAirPackets, AddressOf NewInAirPackets_Event
End Sub
'...
Private Sub GetXYIndexes(ByRef theXIndex As Integer, _
ByRef theYIndex As Integer)
' Get the indexes of the X and Y data within the raw
' packet data array.
Dim theGuids() As Guid = theInkOverlay.DesiredPacketDescription
Dim i As Integer
For i = 0 To theGuids.Length - 1
If theGuids(i).Equals(PacketProperty.X) Then
theXIndex = i
End If
If theGuids(i).Equals(PacketProperty.Y) Then
theYIndex = i
End If
Next
End Sub
Private Sub NewInAirPackets_Event(ByVal sender As Object, _
ByVal e As InkCollectorNewInAirPacketsEventArgs)
'The event may return with data for multiple packets.
'To simplify things, we'll only look at the first.
If rectInterest.Contains( _
e.PacketData(indexX), e.PacketData(indexY)) Then
If thickBorder = False Then
thickBorder = True
Refresh()
End If
Else
If thickBorder = True Then
thickBorder = False
Refresh()
End If
End If
End Sub
Private Sub Form1_Paint(ByVal sender As Object, _
ByVal e As System.Windows.Forms.PaintEventArgs) _
Handles MyBase.Paint
Dim g As Graphics = e.Graphics
Dim thePen As New Pen(Color.Black, 2)
If thickBorder Then
thePen.Width = 5
End If
g.DrawRectangle(thePen, rectInterest)
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
theInkOverlay.Dispose()
Set theInkOverlay = Nothing
End Sub
End Class
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