vb.net委托代码 vbnet代码生成器

vb6.0和vb.net有什么区别?

VB6.0是基于对象的,VB.NET是面向对象的,它们之间的语法上差距还是比较大的.

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VB.NET生成的是托管代码,必须运行于.NET框架之上.VB6则依赖于VB6运行时的支持.

在WINDOWS的下一版本WINDOWS 7中仍然会提供VB6的支持,不过再到以后的版本就没了.

如果你是第一次学,个人觉得还是直接转向VB.NET学习好了.

C#中的委托和拉姆达表达式用VB.net怎么写

委托主要用于.NETFramework中的事件处理程序和回调函数,它是事件的基础。委托的作用类似于c++中函数指针的作用。不同的是,委托实例独立于它所封装的方法的类,并且方法类型与委托的类型是兼容的。函数指针只能引用静态函数,而委托可以应用静态和实例方法。所有委托都是继承自System.Delegate类,并且有一个调用列表。调用委托时所执行的方法都被存放在这样的一个连接列表中。使用delegate关键字可以声明一个委托。通过将委托与命名方法或匿名方法关联,可以对委托进行实例化。为了与命名方法一起使用,委托必须用具有可接受签名的方法进行实例化。usingSystem;usingSystem.Collections.Generic;usingSystem.Linq;usingSystem.Text;namespaceConsoleApplication1{//声明一个委托delegateintMydelegate();classProgram{staticvoidMain(string[]args){testp=newtest();//将委托指向非静态方法Mydelegatem=newMydelegate(p.InstanceMethod);//调用非静态方法m();//将委托指向静态方法m=newMydelegate(test.StaticMethod);//调用静态方法m();Console.Read();}}publicclasstest{publicintInstanceMethod(){Console.WriteLine("正在调用非静态方法InstanceMethod().");return0;}staticpublicintStaticMethod(){Console.WriteLine("正在调用静态方法StaticMethod()。。。。");return0;}}}

求助vb.net处理多线程的问题,想用委托来做以下代码。两个button控件和两个textbox控件。

Public Class Form1   

Delegate Sub MySubDelegate(ByVal txt As String,ByVal num as integer)

Private Sub txtW(ByVal txt As String,ByVal num as integer)

Dim msgd As New MySubDelegate(AddressOf Me.txtW1)

Me.Invoke(msgd, txt,num)

End Sub

Private Sub txtW1(ByVal txt As String,ByVal num as integer)

if num=1 then

TextBox1.Text=txt

else

TextBox2.Text=txt

end if

End Sub

Dim t1, t2 As Threading.Thread

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

End Sub

Private Sub autoAction1()

For i = 0 To 100

Delay(10)

txtw(i.ToString,1)

Next

t1.Abort()

End Sub

Private Sub autoAction2()

For i = 0 To 100

Delay(10)

txtw(i.ToString,2)

Next

t2.Abort()

End Sub

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

t1 = New Threading.Thread(AddressOf autoAction1)

t1.Start()

End Sub

Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click

t2 = New Threading.Thread(AddressOf autoAction2)

t2.Start()

End Sub

Public Sub Delay(ByRef Interval As Double)  'Interval单位为毫秒

Dim time As DateTime = DateTime.Now

Dim Span As Double = Interval * 10000

While ((DateTime.Now.Ticks - time.Ticks) Span)

Application.DoEvents()

End While

End Sub

End Class

vb.net高手请帮帮我看看下面这代码什么意思,详解哦,先谢了,Handles 作用是什么

在VB.Net当中,事件的"关联"是需要明显标志的,不像vb6当中,声明一个过程就是事件执行过程了

Handles用来静态"关联"一个或多个事件到一个过程

"关联"时,过程的签名必须与事件的签名相同(签名的意义请查看相关文档)

在VB.Net当中,事件也是一个对象(VB.Net当中一切皆为对象)

使用Handles时实际就相当于创建了一个对委托的实现(委托的意义请查看相关文档)

可以简单的认为,当事件被触发时,被Handles"关联"了的那些过程代码将被执行

而且,被"关联"的过程可以任意起名,不需要与事件和对象的名称相对应

上述代码如果去掉Handles 及其后面的内容,它将是一个最普通不过的过程,与其它过程没有两样,也不会有任何事件被触发时去执行这段代码,正因为加入了Handles 及其后面的一堆事件,它才会因事件被触发而被执行

说得再简单一点: 当PictureBox1.DoubleClick, PictureBox4.DoubleClick, PictureBox3.DoubleClick,PictureBox2.DoubleClick当中的任何一个事件被触发时,上述这个过程的代码都将被执行

再说说参数: sender表示触发了此事件的对象,在这里就是PictureBox1/PictureBox2/PictureBox3/PictureBox4当中的某一个,利用它能知道到底是哪个对象触发了此事件,e在这里没有用处,利用不到什么,之所以有它,是因为Object/EventArgs是.Net事件的基本签名方式,它的好处在你以后对.Net深入之后能体会到.

这些参数的值都是通过被触发的事件传递过来的,可以简单的认为[事件调用了此过程并为参数赋了值]

vb.net中如何用事件和委托,会C#中的事件和委托,但不知VB.net中的语法,望给个简单的例子熟悉语法。

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 Sub

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)

End Sub

二、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

End Sub

' 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

Get

Return _snoozePressed

End Get

End Property

' The AlarmText property that contains the wake-up message.

'

Public ReadOnly Property AlarmText() As String

Get

If _snoozePressed Then

Return "Wake Up!!! Snooze time is over."

Else

Return "Wake Up!"

End If

End Get

End Property

End Class

' 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

Get

Return stopFlag

End Get

Set

stopFlag = value

End Set

End Property

' The SnoozePressed property indicates whether the snooze

' button is pressed on the alarm when the alarm event is generated.

'

Public Property SnoozePressed() As Boolean

Get

Return _snoozePressed

End Get

Set

_snoozePressed = value

End Set

End Property

' 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)

End Sub

' 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

' with a time delay of 300 milliseconds,

' 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

Else

If _snoozePressed Then

System.Threading.Thread.Sleep(1000)

If (True) Then

Dim e As New AlarmEventArgs(_snoozePressed, nrings)

OnAlarm(e)

End If

Else

System.Threading.Thread.Sleep(300)

Dim e As New AlarmEventArgs(_snoozePressed, nrings)

OnAlarm(e)

End If

End If

Loop

End Sub

End Class

' 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

Else

If input.Equals("N") Or input.Equals("n") Then

CType(sender, AlarmClock).SnoozePressed = True

Return

Else

CType(sender, AlarmClock).Stop = True

Return

End If

End If

End If

Else

Console.WriteLine(" Let alarm ring? Enter Y")

Console.WriteLine(" Stop Alarm? Enter Q")

Dim input As String = Console.ReadLine()

If input.Equals("Y") Or input.Equals("y") Then

Return

Else

CType(sender, AlarmClock).Stop = True

Return

End If

End If

End Sub

End Class

' 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 Sub

End Class

End Namespace


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