一般多开线程写无限循环行为.
//定义线程
Dim?th?As?New?Threading.Thread(New?Threading.ParameterizedThreadStart(AddressOf?test))
th.Start("aaa")//开始线程,可以传参
//线程执行函数
Public?Sub?test(ob?As?Object)
While?True
Console.WriteLine("线程正在运行中"?ob)
Threading.Thread.Sleep(1000)
End?While
End?Sub
值传递和地址传递(引用)的而导致的问题.
在For Each 的时候
当对象是值对象的时候,等于获得到一个副本.
当对象是引用对象的时候,则是获得到一个指针.
而在For To 的时候
无论对象是什么,你都获得到这个集合指定位置的指针.
更详细的,可以请参考以下内容,或直接去官方的MSDN了解
关于值类型和引用类型:
如果数据类型在它自己的内存分配中存储数据,则该数据类型就是"值类型"."引用类型"包含指向存储数据的其他内存位置的指针.
值类型
值类型包括：
所有数字数据类型
Boolean、Char 和 Date
所有结构,即使其成员是引用类型
枚举,因为其基础类型总是 SByte、Short、Integer、Long、Byte、UShort、UInteger
或 ULong
引用类型
引用类型包括：
String
所有数组,即使其元素是值类型
类类型,如 Form
委托
非类型的元素
以下编程元素未限定为类型,因为您无法将它们中的任何一个指定为声明元素的数据类型：
命名空间
模块
事件
属性和过程
变量、常数和字段
使用对象数据类型
可以将引用类型或值类型指派给 Object 数据类型的变量.Object
变量总是存储指向数据的指针,从不存储数据本身.然而,如果将值类型指派给 Object 变量,则 Object
变量将表现得像存储自己的数据一样.有关更多信息,请参见 Object 数据类型.
通过将 Object 变量传递给 Microsoft.VisualBasic
命名空间中 Information
类的 IsReference
方法,可以确定该变量是用作引用类型还是值类型.如果 Object 变量的内容表示引用类型,则 Information.IsReference 返回 True.
委托三个步骤
①.、声明委托 用Delegate 声明一个委托 类型 参数要和 被委托的方法一样 例如 Delegate Function a(byval x as string) as string
示例：
Module module1
Delegate Function a(ByVal x As Integer, ByVal y As Integer) As Integer '声明委托类型 委托可以使一个对象调用另一个对象的方法
Function sum(ByVal x As Integer, ByVal y As Integer) As Integer
Return (x ◆ y)
End Function
Sub main()
Dim d As New a(AddressOf sum) '实例化委托
Dim s = 0
Console.WriteLine(s.ToString())
MsgBox("")
End Sub
End Module
同学..你这里的写法其实根本没有用到多线程
原因很简单
你是定义了一个T的新线程,但是很可惜你在BeginDoSub这个独立的线程中又定义了一个deSomeSub的委托,并且直接用Me.Invoke把实际的执行任务提交给界面主线程运行了
所以你的图片的处理函数实际上是在主线程中运行的,新线程等于没用
正确的作法是,T定义为SomeSub这个函数为入口的线程,并启动它
在界面进度条更改的时候再使用Invoke来调用委托来进行界面更改.
自己再好好看看吧,时间问题我要走了.
一委托：此示例演示如何将方法与委托关联然后通过委托调用该方法.
创建委托和匹配过程
创建一个名为 MySubDelegate 的委托.
Delegate Sub MySubDelegate(ByVal x As Integer)
声明一个类,该类包含与该委托具有相同签名的方法.
Class class1
Sub Sub1(ByVal x As Integer)
MsgBox("The value of x is: " CStr(x))
End Class
定义一个方法,该方法创建该委托的实例并通过调用内置的 Invoke 方法调用与该委托关联的方法.
Protected Sub DelegateTest()
Dim c1 As New class1
' Create an instance of the delegate.
Dim msd As MySubDelegate = AddressOf c1.Sub1
' Call the method.
msd.Invoke(10)
第二段：事件
下面的示例程序阐释如何在一个类中引发一个事件,然后在另一个类中处理该事件.AlarmClock 类定义公共事件 Alarm,并提供引发该事件的方法.AlarmEventArgs 类派生自 EventArgs,并定义 Alarm 事件特定的数据.WakeMeUp 类定义处理 Alarm 事件的 AlarmRang 方法.AlarmDriver 类一起使用类,将使用 WakeMeUp 的 AlarmRang 方法设置为处理 AlarmClock 的 Alarm 事件.
该示例程序使用事件和委托和引发事件中详细说明的概念.
示例
' EventSample.vb.
'
Option Explicit
Option Strict
Imports System
Imports System.ComponentModel
Imports Microsoft.VisualBasic
Namespace EventSample
' Class that contains the data for
' the alarm event. Derives from System.EventArgs.
Public Class AlarmEventArgs
Inherits EventArgs
Private _snoozePressed As Boolean
Private nrings As Integer
'Constructor.
Public Sub New(snoozePressed As Boolean, nrings As Integer)
Me._snoozePressed = snoozePressed
Me.nrings = nrings
' The NumRings property returns the number of rings
' that the alarm clock has sounded when the alarm event
' is generated.
Public ReadOnly Property NumRings() As Integer
Get
Return nrings
End Get
End Property
' The SnoozePressed property indicates whether the snooze
' button is pressed on the alarm when the alarm event is generated.
Public ReadOnly Property SnoozePressed() As Boolean
Return _snoozePressed
' The AlarmText property that contains the wake-up message.
Public ReadOnly Property AlarmText() As String
If _snoozePressed Then
Return "Wake Up!!! Snooze time is over."
Else
Return "Wake Up!"
End If
' Delegate declaration.
Public Delegate Sub AlarmEventHandler(sender As Object, _
e As AlarmEventArgs)
' The Alarm class that raises the alarm event.
Public Class AlarmClock
Private _snoozePressed As Boolean = False
Private nrings As Integer = 0
Private stopFlag As Boolean = False
' The Stop property indicates whether the
' alarm should be turned off.
Public Property [Stop]() As Boolean
Return stopFlag
Set
stopFlag = value
End Set
Public Property SnoozePressed() As Boolean
_snoozePressed = value
' The event member that is of type AlarmEventHandler.
Public Event Alarm As AlarmEventHandler
' The protected OnAlarm method raises the event by invoking
' the delegates. The sender is always this, the current instance
' of the class.
Protected Overridable Sub OnAlarm(e As AlarmEventArgs)
RaiseEvent Alarm(Me, e)
' This alarm clock does not have
' a user interface.
' To simulate the alarm mechanism it has a loop
' that raises the alarm event at every iteration
' if snooze is not pressed. If snooze is pressed,
' the time delay is 1000 milliseconds.
Public Sub Start()
Do
nrings ◆= 1
If stopFlag Then
Exit Do
System.Threading.Thread.Sleep(1000)
If (True) Then
Dim e As New AlarmEventArgs(_snoozePressed, nrings)
OnAlarm(e)
Loop
' The WakeMeUp class has a method AlarmRang that handles the
' alarm event.
Public Class WakeMeUp
Public Sub AlarmRang(sender As Object, e As AlarmEventArgs)
Console.WriteLine((e.AlarmText ◆ ControlChars.Cr))
If Not e.SnoozePressed Then
If e.NumRings Mod 10 = 0 Then
Console.WriteLine(" Let alarm ring? Enter Y")
Console.WriteLine(" Press Snooze? Enter N")
Console.WriteLine(" Stop Alarm? Enter Q")
Dim input As String = Console.ReadLine()
If input.Equals("Y") Or input.Equals("y") Then
Return
If input.Equals("N") Or input.Equals("n") Then
CType(sender, AlarmClock).SnoozePressed = True
CType(sender, AlarmClock).Stop = True
' The driver class that hooks up the event handling method of
' WakeMeUp to the alarm event of an Alarm object using a delegate.
' In a forms-based application, the driver class is the
' form.
Public Class AlarmDriver
Public Shared Sub Main()
' Instantiates the event receiver.
Dim w As New WakeMeUp()
' Instantiates the event source.
Dim clock As New AlarmClock()
' Wires the AlarmRang method to the Alarm event.
AddHandler clock.Alarm, AddressOf w.AlarmRang
clock.Start()
End Namespace
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