InkCollectorNewInAirPacketsEventHandler 委托

项目
11/04/2008

表示处理 InkCollector 对象的 NewInAirPackets 事件的方法。

命名空间： Microsoft.Ink
程序集： Microsoft.Ink（在 Microsoft.Ink.dll 中）

语法

声明
Public Delegate Sub InkCollectorNewInAirPacketsEventHandler ( _
    sender As Object, _
    e As InkCollectorNewInAirPacketsEventArgs _
)
用法
Dim instance As New InkCollectorNewInAirPacketsEventHandler(AddressOf HandlerMethod)

public delegate void InkCollectorNewInAirPacketsEventHandler(
    Object sender,
    InkCollectorNewInAirPacketsEventArgs e
)

public delegate void InkCollectorNewInAirPacketsEventHandler(
    Object^ sender, 
    InkCollectorNewInAirPacketsEventArgs^ e
)

/** @delegate */
public delegate void InkCollectorNewInAirPacketsEventHandler(
    Object sender,
    InkCollectorNewInAirPacketsEventArgs e
)

JScript 不支持委托。

参数

sender
类型：System.Object
此事件的源 InkCollector 对象。

e
类型：Microsoft.Ink.InkCollectorNewInAirPacketsEventArgs
包含事件数据的 InkCollectorNewInAirPacketsEventArgs 对象。

备注

当用户在 Tablet 附近移动笔并且光标在 InkCollector 对象的窗口中时，或用户在 InkCollector 对象的关联窗口中移动鼠标时，将创建 in-air packet。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。

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，默认事件关注在托管代码 中处于关闭状态，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
    {
    //...

        InkCollector theInkCollector;
        int indexX, indexY;
        Rectangle rectInterest;
        bool thickBorder;

        public Form1()
        {
            //...

            //Initialize the InkCollector object.
            theInkCollector= new InkCollector(Handle);
            theInkCollector.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
            theInkCollector.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 = theInkCollector.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];
            theInkCollector.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)
        {
            theInkCollector.Dispose();
            theInkCollector= null;
        }
    }
}

该 Microsoft(R) Visual Basic(R) .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 theInkCollector As InkCollector
    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 InkCollector object.
        theInkCollector = New InkCollector(Handle)
        theInkCollector.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 theInkCollector.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 = theInkCollector.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
        theInkCollector.Dispose()
        Set theInkCollector = Nothing
    End Sub
End Class