[RESOLVED] [2008] Backgroundworker problems!

[masfenix]

Regarding the following code:

Private Sub bgw_DoWork(ByVal sender As System.Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles bgw.DoWork
        Try
            Dim testEmail As New NetEmail("[email protected]", TextBox4.Text.Trim, TextBox5.Text.Trim, TextBox6.Text.Trim, TextBox7.Text.Trim)
            testEmail.AddEmail("[email protected]")
            testEmail.Timeout = 10000
            testEmail.EnableSSL = CheckBox1.Checked
            testEmail.AddMessage("Test message")
            testEmail.Send("[email protected]", "Test Email")
            btnNext.Enabled = True
            bgw.ReportProgress(100)
        Catch ex As Exception
            bgw.ReportProgress(0, ex)
            btnNext.Enabled = False
        End Try
    End Sub
 
    Private Sub bgw_ProgressChanged(ByVal sender As System.Object, ByVal e As System.ComponentModel.ProgressChangedEventArgs) Handles bgw.ProgressChanged
        If e.ProgressPercentage = 0 Then
            Dim CaughtEx As Exception = DirectCast(e.UserState, Exception)
            MessageBox.Show(CaughtEx.Message)
            MessageBox.Show("Your email settings were not configured")
        ElseIf e.ProgressPercentage = 100 Then
            MessageBox.Show("Test Successfull")
        End If
    End Sub

if an exception is thrown, the first messagebox is showing the the Exception message. The second messagebox Is NOT SHOWN.
if it is succesfull THE MESSAGE BOX is still NOT SHOWN?

does anyone know whatsup?

[jmcilhinney]

You're going about that the wrong way. First of all, you're performing illegal cross-thread operations from your DoWork event handler. Secondly, you're using the ProgressChanged event to notify the user of the final result. That's what the RunWorkerCompleted event is for. You should restructure your code considerably:

Private Structure EmailData
    Public Str1 As String
    Public Str2 As String
    Public Str3 As String
    Public Str4 As String
    Public EnableSSL As Boolean
End Structure
 
Private Sub bgw_DoWork(ByVal sender As System.Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles bgw.DoWork
    Dim data As EmailData
 
    If TypeOf e.Argument Is EmailData Then
        data = DirectCast(e.Argument, EmailData)
    End If
 
    Try
        Dim testEmail As New NetEmail("[email protected]", Data.Str1, Data.Str2, Data.Str3, Data.Str4)
        testEmail.AddEmail("[email protected]")
        testEmail.Timeout = 10000
        testEmail.EnableSSL = Data.EnableSSL
        testEmail.AddMessage("Test message")
        testEmail.Send("[email protected]", "Test Email")
 
        'Success
        e.Result = Nothing
    Catch ex As Exception
        'Failure
        e.Result = ex
    End Try
End Sub
 
Private Sub bgw_RunWorkerCompleted(ByVal sender As Object, ByVal e As System.ComponentModel.RunWorkerCompletedEventArgs) Handles bgw.RunWorkerCompleted
    Dim err As Exception = TryCast(e.Result, Exception)
 
    If err Is Nothing Then
        'Success
        btnNext.Enabled = True
        MessageBox.Show("Test Successfull")
    Else
        'Failure
        btnNext.Enabled = False
        MessageBox.Show(err.Message)
        MessageBox.Show("Your email settings were not configured")
    End If
End Sub

Now you're using the event that is specifically intended to notify you that the background operation is complete to notify you that the background operation is complete.

You're also not accessing any controls in the background thread, as is appropriate. When you call RunWorkerAsync on the BackgroundWorker you need to create an EmailData object and pass it in:

Dim data As EmailData
 
With data
    .Str1 = Me.TextBox4.Text.Trim()
    .Str1 = Me.TextBox5.Text.Trim()
    .Str1 = Me.TextBox6.Text.Trim()
    .Str1 = Me.TextBox7.Text.Trim()
    .EnableSSL = Me.CheckBox1.Checked
End With
 
Me.bgw.RunWorkerAsync(data)

[masfenix]

Hey man thanks a lot..

I didnt even know there was a e.result.

By the way, apart from the illegal cross thread operations, why didnt my code work? Liek how come only the first messagebox showed, but not the second?

Edit: I can't even give you more repuatation cuz I have to spread it around! lol

[jmcilhinney]

I'm not sure what was causing that symptom in your original code but I'm afraid I don't care to investigate given that the design was inappropriate anyway.