InkOverlay.NewInAirPackets 事件
当 InkOverlay 对象检测到 in-air packet 时发生。
命名空间： Microsoft.Ink
程序集： Microsoft.Ink（在 Microsoft.Ink.dll 中）
语法
声明
Public Event NewInAirPackets As InkCollectorNewInAirPacketsEventHandler
用法
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);
}
/** @event */
public void add_NewInAirPackets (InkCollectorNewInAirPacketsEventHandler value)
/** @event */
public void remove_NewInAirPackets (InkCollectorNewInAirPacketsEventHandler value)
JScript 不支持事件。
备注
当用户在 Tablet 上下文 的物理检测范围（邻近）内移动光标、并且光标在 InkOverlay 对象的窗口内，或者当用户在 InkOverlay 对象的关联窗口中移动鼠标时，会发生此事件。
NewInAirPackets 事件会快速生成，事件处理程序必须快速执行，否则会降低性能。
事件处理程序接收 InkCollectorNewInAirPacketsEventArgs 类型的参数，该参数包含有关此事件的数据。
创建 InkCollectorNewInAirPacketsEventHandler 委托时，需要标识将处理该事件的方法。若要将该事件与事件处理程序关联，请将该委托的一个实例添加到事件中。除非移除了该委托，否则每当发生该事件时就会调用此事件处理程序。出于性能方面的原因，默认事件关注处于关闭状态，但如果添加事件处理程序，它将自动打开。
不仅在插入墨迹时，甚至在选择或擦除模式下，也会激发 NewInAirPackets 事件。这就要求您监视编辑模式（您负责设置）并在解释事件之前注意模式。这一要求的好处在于通过注意平台事件在平台上获得更大的创新自由。
示例
此 C# 示例在窗体上绘制一个矩形，in-air packet 在矩形内时使用粗边框，在矩形外时使用窄边框。它演示如何使用数据包事件来控制应用程序行为。
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;
}
}
}
此 Microsoft Visual Basic .NET 示例在窗体上绘制一个矩形，in-air packet 在矩形内时使用粗边框，在矩形外时使用窄边框。它演示如何使用数据包事件来控制应用程序行为。
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
平台
Windows Vista
.NET Framework 和 .NET Compact Framework 并不是对每个平台的所有版本都提供支持。有关支持的版本的列表，请参见.NET Framework 系统要求。
版本信息
.NET Framework
受以下版本支持：3.0