vb.net多线程同步调用实例

当前位置:

首页 > VB.net教程 >

vb.net多线程同步调用实例

以前一直感觉多线程比较难懂，最近由于需要，没办法必须克服，这不看了几遍书，终于理解差不多了，先把最开始的一个实例弄上来吧。

Imports System.Threading '看名字就知道，这个类干什么用的，多线程应用程序都要用这个类

Public Delegate Function BinaryOp(ByVal x As Integer, ByVal y As Integer) As Integer

Module Module1

Sub Main()

Console.WriteLine("***** Synch Delegate Review *****")

' Print out the ID of the executing thread.

Console.WriteLine("Main() invoked on thread {0}.", Thread.CurrentThread.ManagedThreadId)

' Invoke Add() in a synchronous manner.

Dim b As New BinaryOp(AddressOf Add)

' Could also write b. Invoke(10, 10); 注意区别同步方式是invoke,已不是beginInvoke

Dim answer As Integer = b(10, 10)

' These lines will not execute until

' the Add() method has completed.

Console.WriteLine("Doing more work in Main()!")

Console.WriteLine("10 + 10 is {0}.", answer)

Console.ReadLine()

End Sub

Private Function Add(ByVal x As Integer, ByVal y As Integer) As Integer

' Print out the ID of the executing thread.

Console.WriteLine("Add() invoked on thread {0}.", Thread.CurrentThread.ManagedThreadId)

' Pause to simulate a lengthy operation.

Thread.Sleep(5000)

Return x + y

End Function

End Module

不知道大家怎么理解这个同步和异步。反正这个不大好理解,我觉得主要就看是否有阻塞或者尽可能小的阻塞。特别是同步调用方式和同步调用线程的区别，特别是很多翻译过来的东西，最好还是看原文和实例。

---------------------------一以下异步调用代码----------------------------------------------------

Imports System.Threading '看名字就知道，这个类干什么用的，多线程应用程序都要用这个类

Public Delegate Function BinaryOp(ByVal x As Integer, ByVal y As Integer) As Integer

Module Module1

Sub main()

Console.WriteLine("***** Async Delegate Invocation *****")

' Print out the ID of the executing thread.

Console.WriteLine("Main() invoked on thread {0}.", Thread.CurrentThread.ManagedThreadId)

Dim b As New BinaryOp(AddressOf Add)

Dim iftAR As IAsyncResult = b.BeginInvoke(10, 10, Nothing, Nothing)

' This message will keep printing until

' the Add() method is finished.

Do While Not iftAR.IsCompleted

Console.WriteLine("Doing more work in Main()!")

Thread.Sleep(1000)

Loop

' Now we know the Add() method is complete.

Dim answer As Integer = b.EndInvoke(iftAR)

Console.WriteLine("10 + 10 is {0}.", answer)

Console.ReadLine()

End Sub

Private Function Add(ByVal x As Integer, ByVal y As Integer) As Integer

' Print out the ID of the executing thread.

Console.WriteLine("Add() invoked on thread {0}.", Thread.CurrentThread.ManagedThreadId)

' Pause to simulate a lengthy operation.

Thread.Sleep(5000)

Return x + y

End Function

End Module

栏目列表