MultiThreading 2

Here We Discuss About Two Threads Associate With Function:-

Here we take:-

1)open window form in with new project in VS.

1)Take two buttons and two level,See in figure:-

Put this code in place of given events:-

Public Class Form3

    Public Sub setText()

        For i = 0 To 50

            Label1.Text = i.ToString

            Threading.Thread.Sleep(100)

        Next i

    End Sub

    Public Sub Mysub()

        setText()

    End Sub

    Public Sub Mysub1()

        For i = 0 To 50

            Label2.Text = i.ToString

            Threading.Thread.Sleep(100)

        Next i

    End Sub

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

        Mysub()       

    End Sub

    Private Sub Button2_Click(sender As System.Object, e As System.EventArgs) Handles Button2.Click

        Mysub1()       

    End Sub

    Private Sub Form3_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load

        CheckForIllegalCrossThreadCalls = False

    End Sub

End Class

In this code ,we find at run time :-

a)if you click on button1 ,then you can  able to move window and click on button2.

b)you must be wait for completion of  execution of buttone1's function.

c) we can not able to do anther work parallely.

Then after we add some line of code of thread in our above program:-

        Dim MyThread As New System.Threading.Thread(AddressOf Mysub1)

        MyThread.Start()

And remove/comment out  'Mysub() then See the complete code with additional code:-

Public Class Form3

    Public Sub setText()

        For i = 0 To 50

            Label1.Text = i.ToString

            Threading.Thread.Sleep(100)

        Next i

    End Sub

    Public Sub Mysub()

        setText()

    End Sub

    Public Sub Mysub1()

        For i = 0 To 50

            Label2.Text = i.ToString

            Threading.Thread.Sleep(100)

        Next i

    End Sub

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

        'Mysub()

        Dim MyThread As New System.Threading.Thread(AddressOf Mysub)

        MyThread.Start()

    End Sub

    Private Sub Button2_Click(sender As System.Object, e As System.EventArgs) Handles Button2.Click

        'Mysub1()

        Dim MyThread As New System.Threading.Thread(AddressOf Mysub1)

        MyThread.Start()

    End Sub

    Private Sub Form3_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load

        CheckForIllegalCrossThreadCalls = False

    End Sub

End Class

We find both the buttons work parallely and also we can able drag drop window :-

One Important part of this code,we need to check a cross-thread operation,which is occur due to two or more thread run exclusively.for this we write this line in Form3_Load event

 CheckForIllegalCrossThreadCalls = False

If we not  write this code it generate error shown in figure:-

Conclusion 

Multi-threading is necessary for work with multi task  operation.