CODEWITHSUNDEEP
vb.netmultithreading
user2153378
user2153378

Reputation:

Thread in for-loop

How do I know if a thread is finished when I create it in a loop?
Simplified code:

Public Sub LoadExcelFiles()
AddMore: 
        Dim t As New Thread(New ThreadStart(AddressOf CreateExcelFile))
        t.Start()

'Check if there are more files.
'If yes: GoTo AddMore
End Sub

How do I know when thread 't' is completed? I want to add the file created by 't' into a treeview.
Another problem is, when the user drops 33 files, I have 11 threads running at the same time (3 excelfiles are used per thread)

Upvotes: 0

Views: 76

Answers (2)

user2153378
user2153378

Reputation:

An interesting article about the answer of @Paul Deen (wish is a good solution) can be found at http://tech.xster.net/tips/multi-threading-in-vb-net/

Tho I did it another way.

    Dim t As New Thread(New ThreadStart(AddressOf CreateExcelFile))
    If t.IsAlive Then
        t.Join()
    Else
        t.Start()
    End If

'Some code here

    While t.IsAlive
        System.Threading.Thread.Sleep("500")
    End While

    MessageBox.Show("All Files Completed")

Upvotes: 1

Paul Deen
Paul Deen

Reputation: 455

You could consider doing it like this:

Delegate Sub CreateExcelFileAsync()
Public Sub LoadExcelFiles()
        Dim d As New CreateExcelFileAsync(AddressOf CreateExcelFile)

        Dim result As IAsyncResult = d.BeginInvoke(Nothing, Nothing)

        '..
        'more work
        '..
        'wait until completed before starting over

        If Not result.IsCompleted() Then
            result.AsyncWaitHandle.WaitOne()
        End If

        d.EndInvoke(result)
End Sub

This way you can use the AsyncResult to check the completion.

Upvotes: 1

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