vb.net中如何結(jié)束一個(gè)線程

vb.net中如何結(jié)束一個(gè)線程

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一般而言,如果您想終止一個(gè)線程,您可以使用System.Threading.Thread類的Abort方法. 例如:

Dim worker As ThreadStart = New ThreadStart(AddressOf workerthreadmethod)

Dim t As Thread = New Thread(worker)

t.Start()

MessageBox.Show("Wait for a while for the thread to start.")

MessageBox.Show(t.ThreadState.ToString())

t.Abort()

MessageBox.Show(t.ThreadState.ToString())

t.Join()

MessageBox.Show(t.ThreadState.ToString())

當(dāng)然,在調(diào)用Abort方法后,線程并不是立刻終止,要等線程的所有finally快中的代碼完成后才會(huì)完全終止. 所以在主線程中可以用Join方法來同步,當(dāng)線程還未完全終止時(shí),t.Join()將處于等待,直到t線程完全結(jié)束后再繼續(xù)執(zhí)行后面的語句。

Abort方法是會(huì)導(dǎo)致線程跳出一個(gè)異常錯(cuò)誤的，你需要在代碼中捕獲該異常。下面是一個(gè)比較完整的VB.NET線程例子：

Imports System

Imports System.Threading

Public Class MyTestApp

Public Shared Sub Main()

Dim t As New Thread(New ThreadStart(AddressOf MyThreadMethod))

'Start the thread

t.Start()

MsgBox("Are you ready to kill the thread?")

'Kill the child thread and this will cause the thread raise an exception

t.Abort()

' Wait for the thread to exit

t.Join()

MsgBox("The secondary thread has terminated.")

End Sub

Shared Sub MyThreadMethod()

Dim i As Integer

Try

Do While True

Thread.CurrentThread.Sleep(1000)

Console.WriteLine("This is the secondary thread running.")

Loop

Catch e As ThreadAbortException

MsgBox("This thread is going to be terminated by the Abort method in the Main function")

End Try

End Sub

End Class

Thread.Abort()方法用來永久銷毀一個(gè)線程，而且將拋出ThreadAbortException異常。使終結(jié)的線程可以捕獲到異常但是很難控制恢復(fù)，僅有的辦法是調(diào)用Thread.ResetAbort()來取消剛才的調(diào)用，而且只有當(dāng)這個(gè)異常是由于被調(diào)用線程引起的異常。因此，A線程可以正確的使用Thread.Abort()方法作用于B線程，但是B線程卻不能調(diào)用Thread.ResetAbort()來取消Thread.Abort()操作。

多線程 線程池 VB.NET

這個(gè)沒法做到。原因

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

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

3）正如你觀察到的：線程啟動(dòng)的時(shí)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。

VB.net 如何設(shè)計(jì)多線程運(yùn)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(dòng)多線程進(jìn)程

Application.DoEvents

Next

End Sub

vb.net多線程如何返回參數(shù)，舉個(gè)例子，謝謝

Public?Class?Form1

Public?Class?SquareClass?'把多線程調(diào)用的函數(shù)封裝到類中，通過類事件返回

Public?Value?As?Double

Public?Square?As?Double

Public?Event?ThreadComplete(ByVal?Square?As?Double)

Public?Sub?CalcSquare()

Square?=?Value?*?Value

RaiseEvent?ThreadComplete(Square)

End?Sub

End?Class

Dim?WithEvents?oSquare?As?SquareClass

Private?Sub?Button1_Click(sender?As?Object,?e?As?EventArgs)?Handles?Button1.Click?'多線程返回值測(cè)試，當(dāng)線程運(yùn)行完成激發(fā)事件

oSquare?=?New?SquareClass()

Dim?t?As?New?Threading.Thread(AddressOf?oSquare.CalcSquare)

oSquare.Value?=?30

t.Start()

End?Sub

Sub?SquareEventHandler(ByVal?Square?As?Double)?Handles?oSquare.ThreadComplete?'響應(yīng)事件函數(shù)

MsgBox("The?square?is?"??Square)

End?Sub

End?Class