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Creating Threads

To create threads lets work with an example

, Programming with Visual Basic.NET- Black Book. Open a new windows application and name it as Thread and add a class named count1 using the Projects->Add Class item. This class will count from 1 to a specified value in a data member named CountTo when you call the Count method. After the count has reached the value in CountTo, a FinishedCounting event will occur. The code for the Count class looks like this:

Public Class Count1
Public CountTo as Integer
Public event FinishedCounting(By Val NumberOfMatches as Integer)
Sub Count()
Dim ind,tot as Integer
tot=0
For ind=1 to CountTo
tot+=1
Next ind
RaiseEvent FinishedCounting(tot)
'makes the FinishedCounting event to occur
End Sub
End Class

Let's use this class with a new thread. Get back to the main form and create an object of this class, counter1, and a new thread, Thread1. The code looks like this:

Public Class Form1 Inherits System.Windows.Forms.Form
Dim counter1 as new Count1()
Dim Thread1 as New System.Threading.Thread(Address of counter.Count)

Drag a Button and two TextBoxes (TextBox1, TextBox2) onto the form. Enter a number in TextBox1. The reason for entering a number in textbox is to allow the code to read the value specified in TextBox1 and display that value in TextBox2, with threading. The code for that looks like this:

Public Class Form1 Inherits System.Windows.Forms.Form
Dim counter1 as new Count1()
Dim Thread1 as New System.Threading.Thread(Address of counter.Count)
Private Sub Button1_Click(ByVal sender as System.Object, ByVal e as System.EventArgs)_
Handles Button1.Click
TextBox2.Text=" "
counter1.CountTo=TextBox1.Text
AddHandler counter1.FinishedCounting,AddressOfFinishedCountingEventHandler
'adding handler to handle FinishedCounting Event
Thread1.Start()
'starting the thread
End Sub
Sub FinishedCountingEventHandler(ByVal Count as Integer)
'FinishedCountingEventHandler
TextBox2.Text=Count
End Sub

The result of the above code displays the value entered in TextBox1, in TextBox2 with the difference being the Thread counting the value from 1 to the value entered in TextBox1.

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threading in .net

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