[RESOLVED] Thread Form and Owner

[jmcilhinney]

Thanks boops boops

I know how to use the background worker and that's not what i intend to do...

The main form should remain blocked, it's a critical operation, so i need someway to tell the user that the operation it's running.
Like i wrote i can make the form the top most, but then it'll be over other applications and i don't like that.
The other option by setting the owner of the form, i can bypass the cross thread error, setting the CheckForIllegalCrossThreadCalls = False, before starting the new thread and then everything works fine... I just don't want to use this, but if there isn't any other way...

Thanks

A BackgroundWorker is perfect for this... if you use it properly. What you can do is design a form that has a ProgressBar on it and contains a BackgroundWorker. You then declare a constructor in that form that takes a DoWorkEventHandler delegate as an argument. In your main form, you write a DoWork event handler but without a Handles clause and when you create the progress form you pass a delegate for that method to it. That method is then used as the handler for the DoWork event of the BackgroundWorker in the progress form. E.g.

Imports System.Threading
Imports System.ComponentModel
 
Public Class MainForm
 
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Using dialogue As New WorkingDialogue(AddressOf BackgroundWorker_DoWork)
            dialogue.ShowDialog()
        End Using
 
        MessageBox.Show("Task complete")
    End Sub
 
    Private Sub BackgroundWorker_DoWork(sender As Object, e As System.ComponentModel.DoWorkEventArgs)
        Dim worker = DirectCast(sender, BackgroundWorker)
 
        For i = 1 To 100
            Thread.Sleep(100)
            worker.ReportProgress(i)
        Next
    End Sub
 
End Class

Imports System.ComponentModel
 
Public Class WorkingDialogue
 
    Public Sub New(doWorkHandler As DoWorkEventHandler)
        ' This call is required by the designer.
        InitializeComponent()
 
        ' Add any initialization after the InitializeComponent() call.
 
        AddHandler Me.BackgroundWorker1.DoWork, doWorkHandler
    End Sub
 
    Private Sub WorkingDialogue_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Me.BackgroundWorker1.RunWorkerAsync()
    End Sub
 
    Private Sub BackgroundWorker1_ProgressChanged(sender As Object, e As ProgressChangedEventArgs) Handles BackgroundWorker1.ProgressChanged
        Me.ProgressBar1.Value = e.ProgressPercentage
    End Sub
 
    Private Sub BackgroundWorker1_RunWorkerCompleted(sender As Object, e As RunWorkerCompletedEventArgs) Handles BackgroundWorker1.RunWorkerCompleted
        Me.Close()
    End Sub
End Class