vb.net如何用線程池實現(xiàn)多線程事件響應(yīng)

這個沒法做到。原因

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1）當(dāng)你將方法排入線程池隊列后，此方法在有線程池線程變得可用時執(zhí)行。

2）線程池中某個線程的可用與不可用，是由.net 后臺決定，用戶程序無法控制的

3）正如你觀察到的：線程啟動的時間不同，有快有慢，這恰恰說明線程池起作用了：線程池的調(diào)度試圖讓程序響應(yīng)達(dá)到最佳。

在vb.net中，多線程如何使用

Sub Main() Dim thr As New Thread(AddressOf 循環(huán)) thr.Start("a") End Sub Sub 循環(huán)(a() As String) '這里隨你干什么循環(huán)也行 For Each i As String In a MsgBox(i) Next End Sub

VB.NET 簡單多線程

多線程一般是不推薦用的，因為線程之間如果有共享資源的話會引起競爭，需要加鎖處理；而且線程間沒有時序關(guān)系，所以你在調(diào)試中可能會出現(xiàn)異步處理結(jié)束順序與開始處理順序不一致的情況（我在調(diào)試中已經(jīng)發(fā)現(xiàn)該問題）。

針對你提出的這個問題，采用了多線程處理，利用的是BackgroundWorker也就是異步處理控件進行了處理。

代碼已經(jīng)經(jīng)過調(diào)試通過。歡迎交流，如有問題，留下QQ或其他聯(lián)系方式。

代碼如下，并附程序截圖。

‘---------------------------------------------------

Imports?System.ComponentModel?'導(dǎo)入異步控件命名空間

Public?Class?Form1

Private?howmany?As?Integer?=?10

Private?AnalysisNumber(0?To?howmany?-?1)?As?BackgroundWorker

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

ListBox1.Items.Clear()

creatNewBackgroundWorker()

addHandle()

startWork()

End?Sub

Private?Sub?creatNewBackgroundWorker()

For?i?As?Integer?=?0?To?AnalysisNumber.Length?-?1

AnalysisNumber(i)?=?New?BackgroundWorker

Next

End?Sub

Private?Sub?addHandle()

For?i?As?Integer?=?0?To?AnalysisNumber.Length?-?1

AddHandler?AnalysisNumber(i).DoWork,?AddressOf?AnalysisNumber_DoWork

AddHandler?AnalysisNumber(i).RunWorkerCompleted,?AddressOf?AnalysisNumber_RunWorkerCompleted

Next

End?Sub

Private?Sub?startWork()

For?i?As?Integer?=?0?To?9

Dim?temp(0?To?9)?As?Integer

For?j?As?Integer?=?1?To?10

temp(j?-?1)?=?10?*?i?+?j

Next

AnalysisNumber(i).RunWorkerAsync(temp)

Next

End?Sub

Private?Sub?AnalysisNumber_DoWork(ByVal?sender?As?Object,?ByVal?e?As?System.ComponentModel.DoWorkEventArgs)

Dim?data?As?Integer()

data?=?CType(e.Argument,?Integer())

Dim?temp?As?Integer

For?i?As?Integer?=?0?To?data.Length?-?1

temp?=?data(i)

data(i)?=?temp?*?temp

Next

e.Result?=?data

End?Sub

Private?Sub?AnalysisNumber_RunWorkerCompleted(ByVal?sender?As?Object,?ByVal?e?As?System.ComponentModel.RunWorkerCompletedEventArgs)

Dim?data?As?Integer()

data?=?CType(e.Result,?Integer())

For?i?As?Integer?=?0?To?data.Length?-?1

ListBox1.Items.Add(data(i))

Next

End?Sub

End?Class

什么是多線程技術(shù)？在VB 中如何使用？

vb6可以實現(xiàn)多線程,不過比較麻煩,vb.net完全支持多線程,請參見msdn.

至于vb6實現(xiàn)多線程請看CreateThread這個API函數(shù).以下有詳細(xì)方案:

用VB寫多線程程序用到的第一個API函數(shù)是CreateThread，這個函數(shù)的聲明如下：

Private Declare Function CreateThread Lib "kernel32" (ByVal lpThreadAttributes As Any, ByVal dwStackSize As Long, ByVal lpStartAddress As Long, lpParameter As Any, ByVal dwCreationFlags As Long, lpThreadId As Long)As Long

這個函數(shù)的返回值是線程的句柄，它的參數(shù)含義如下：

1.lpThreadAttributes：這個參數(shù)表明函數(shù)的返回句柄是否可被子進程繼承，如果可被繼承，則指向一個SECURITY_ATTRIBUTES的結(jié)構(gòu)，否則設(shè)為vbnull。

2.dwStackSize：這個參數(shù)設(shè)置線程的堆棧大小。

3.lpStartAddress：這個參數(shù)指明這個線程函數(shù)的起始地址。

4.lpParameter：這個參數(shù)是傳給線程函數(shù)的參數(shù)。

5.dwCreationFlags：這個參數(shù)設(shè)置當(dāng)線程創(chuàng)建時的初始狀態(tài)，掛起，運行等等。

6.lpThreadId：這個參數(shù)是待創(chuàng)建線程的ID號。

假設(shè)創(chuàng)建一個管理線程的類clsThreads，用類的一個公用函數(shù)Initialize來初始化線程，用ResumeThread和SuspendThread函數(shù)來激活線程，實現(xiàn)代碼如下：

Private Type udtThread

Handle As Long

Enabled As Boolean

End Type

Private uThread As udtThread

Private Const CREATE_SUSPENDED As Long = H4

Private Declare Function CreateThread Lib "kernel32" (ByVal lpThreadAttributes As Any, ByVal dwStackSize As Long, ByVal lpStartAddress As Long, lpParameter As Any, ByVal dwCreationFlags As Long, lpThreadId As Long) As Long

Private Declare Function ResumeThread Lib "kernel32" (ByVal hThread As Long) As Long

Private Declare Function SuspendThread Lib "kernel32" (ByVal hThread As Long) As Long

Private Declare Function TerminateThread Lib "kernel32" (ByVal hThread As Long, ByVal dwExitCode As Long) As Long

Public Sub Initialize(ByVal lpfnBasFunc As Long) '初始化線程

Dim lStackSize As Long, lCreationFlags As Long, lpThreadId As Long, lNull As Long

On Error Resume Next

lNull = 0 '創(chuàng)建一個空指針

lStackSize = 0 '0表示用exe的stack size

lCreationFlags = CREATE_SUSPENDED '表示初始化后先不激活，讓別人來激活

uThread.Handle = CreateThread(lNull, lStackSize, lpfnBasFunc, lNull, lCreationFlags, lpThreadId)

If uThread.Handle = lNull Then MsgBox "Create thread failed!"

End Sub

Public Property Get Enabled() As Boolean

On Error Resume Next

Enabled = uThread.Enabled

End Property

Public Property Let Enabled(ByVal vNewValue As Boolean)

On Error Resume Next

If vNewValue And (Not uThread.Enabled) Then

ResumeThread uThread.Handle '激活線程

uThread.Enabled = True

ElseIf uThread.Enabled Then

SuspendThread uThread.Handle

uThread.Enabled = False

End If

End Property

Private Sub Class_Terminate() '終止線程

On Error Resume Next

Call TerminateThread(uThread.Handle, 0)

End Sub

以上內(nèi)容在類模塊clsThreads中，有了它就可以在窗體中實現(xiàn)多線程了。下面以一個簡單的例子來說明如何創(chuàng)建多線程(以2個線程為例)。

在form1中添加picture1和picture2兩個圖片框，以及一個command1按鈕，在工程中添加一個bas模塊，該模塊的代碼如下：

Option Explicit

Private Declare Function GetTickCount Lib "kernel32" () As Long

Public Sub FlickerTop()

Static BgColor As Long

Dim lTick As Long, lCounter As Long

On Error Resume Next

For lCounter = 0 To 60000

BgColor = lCounter Mod 256

Form1.Picture1.BackColor = RGB(BgColor, 0, 0) '變化圖片框的顏色

lTick = GetTickCount

While GetTickCount - lTick 10 '延遲10個毫秒時間

Wend

Next

End Sub

Public Sub FlickerBottom()

Static BgColor As Long

Dim lTick As Long, lCounter As Long

On Error Resume Next

For lCounter = 0 To 60000

BgColor = lCounter Mod 256

Form1.Picture2.BackColor = RGB(0, BgColor, 0)

lTick = GetTickCount

While GetTickCount - lTick 10

Wend

Next

End Sub

最后在form1中用下面的代碼來創(chuàng)建兩個線程，

Option Explicit

Public myThreadTop As New clsThreads, myThreadBottom As New clsThreads

Private Sub Command1_Click()

On Error Resume Next

With myThreadTop

.Initialize AddressOf FlickerTop

.Enabled = True

End With

With myThreadBottom

.Initialize AddressOf FlickerBottom

.Enabled = True

End With

MsgBox "看看會有什么..."

Set myThreadTop = Nothing

Set myThreadBottom = Nothing

End Sub

VB.net 如何設(shè)計多線程運行

Sub Main()

Dim thr As Thread

For Pi As Integer=0 To 4 //啟用5線程

MulParams =Pi vbTab sFile vbTab dFile vbTab 1 vbTab DelN vbTab cr vbTab cg vbTab cb vbTab IndexI

GlobalParamas(pi)=MulParams .Split(vbTab)

thr=New Thread(AddressOf MyMulThreadCaller)

thr.Start() //啟動多線程進程

Application.DoEvents

Next

End Sub