Question

i have a function that contains the following

  WebUpdateThread = New System.Threading.Thread(AddressOf generatecids)
    WebUpdateThread.SetApartmentState(ApartmentState.STA)
    WebUpdateThread.Start()

    'after starting the thread i have some code that i want to run when the thread    finshes its work which takes about 3-4 hours
'if i put for example 
MsgBox("something")

the message box shows as soon as the thread starts, how do i make it wait until the thread is finshed?

is there something more sufficient than an infitine while loop that checks the thread state?

Answer 1

You can use the BackGroundWorker Class, it is designed for just this scenario, you also can implement progress indication so your user is not wondering what is happening by using the ProgressChanged Event:

Example:

Imports System.Threading
Imports System.ComponentModel


Public Class Form1
    Dim WebUpdateWorker As BackgroundWorker

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        WebUpdateWorker = New BackgroundWorker
        AddHandler WebUpdateWorker.DoWork, AddressOf DoWork
        AddHandler WebUpdateWorker.RunWorkerCompleted, AddressOf WorkFinished
        WebUpdateWorker.RunWorkerAsync()

    End Sub

    Public Sub generatecids()
        System.Threading.Thread.Sleep(20000)
    End Sub

    Private Sub DoWork(sender As Object, e As DoWorkEventArgs)
        generatecids()
    End Sub

    Private Sub WorkFinished(sender As Object, e As RunWorkerCompletedEventArgs)
        MsgBox("something")
    End Sub

End Class