ThreadState always is "Unstarted" - vb.net

Question

When I start a thread, the ThreadState always is "Unstarted" even if I do a "Thread.Abort()", my thread starts and finish the work good... I don't know why I get that always the same state.
Dim thread_1 As System.Threading.Thread = New Threading.Thread(AddressOf mithread)
thread_1.Start()
System.Threading.Thread.Sleep(100)
While not thread_1.ThreadState = Threading.ThreadState.Running
MsgBox(thread_1.ThreadState.ToString) ' "Unstarted"
thread_1.Abort()
MsgBox(thread_1.ThreadState.ToString) ' "Unstarted" again and again...
End While
UPDATE
This is the sub who calls the thread, and the problem is the "while" statament is not waiting,
PS: You can see a comment explanation at the middle of this sub:
public sub...
...
If Not playerargs = Nothing Then
If randomize.Checked = True Then
Dim thread_1 As System.Threading.Thread = New Threading.Thread(AddressOf mithread)
thread_1.Start()
System.Threading.Thread.Sleep(50)
While thread_1.ThreadState = Threading.ThreadState.Running
Windows.Forms.Application.DoEvents()
End While
Else
progresslabel.Text = "All files added..."
End If
' HERE IS THE PROBLEM, IF I CHECK "AUTOCLOSE" CHECKBOX THEN,
' THE FORM ALWAYS TRY TO CLOSE BEFORE THREAD IS COMPLETED:
' -----------------------------------------
If autoclose.Checked = True Then Me.Close()
'------------------------------------------
Else
...
End Sub
And here is the "mithread" thread:
Public Sub mithread()
Dim Str As String
Dim Pattern As String = ControlChars.Quote
Dim ArgsArray() As String
Str = Replace(playerargs, " " & ControlChars.Quote, "")
ArgsArray = Split(Str, Pattern)
Using objWriter As New System.IO.StreamWriter(Temp_file, False, System.Text.Encoding.UTF8)
Dim n As Integer = 0
Dim count As Integer = 0
Dim foldercount As Integer = -1
For Each folder In ArgsArray
foldercount += 1
If foldercount > 1 Then
InvokeControl(ProgBarPlus1, Sub(x) x.Max = foldercount)
End If
Next
If foldercount = 1 Then
For Each folder In ArgsArray
If Not folder = Nothing Then
Dim di As New IO.DirectoryInfo(folder)
Dim files As IO.FileInfo() = di.GetFiles("*")
Dim file As IO.FileInfo
InvokeControl(ProgBarPlus1, Sub(x) x.Max = files.Count)
For Each file In files
n += 1
CheckPrimeNumber(n)
count += 1
If file.Extension.ToLower = ".lnk" Then
Dim ShotcutTarget As String = Shortcut.ResolveShortcut((file.FullName).ToString())
objWriter.Write(ShotcutTarget & vbCrLf)
Else
objWriter.Write(file.FullName & vbCrLf)
End If
Next
End If
Next
ElseIf foldercount > 1 Then
For Each folder In ArgsArray
If Not folder = Nothing Then
Dim di As New IO.DirectoryInfo(folder)
Dim files As IO.FileInfo() = di.GetFiles("*")
Dim file As IO.FileInfo
InvokeControl(ProgBarPlus1, Sub(x) x.Value += 1)
For Each file In files
If file.Extension.ToLower = ".lnk" Then
Dim ShotcutTarget As String = Shortcut.ResolveShortcut((file.FullName).ToString())
objWriter.Write(ShotcutTarget & vbCrLf)
Else
objWriter.Write(file.FullName & vbCrLf)
End If
Next
End If
Next
End If
End Using
If Not thread_1.ThreadState = Threading.ThreadState.AbortRequested Then
MsgBox(thread_1.ThreadState.ToString)
Randomize_a_file.RandomizeFile(Temp_file)
InvokeControl(ProgBarPlus1, Sub(x) x.Value = 0)
' Process.Start(userSelectedPlayerFilePath, ControlChars.Quote & Temp_file.ToString() & ControlChars.Quote)
InvokeControl(progresslabel, Sub(x) x.Text = "All files launched...")
End If
End Sub

Answer 1

Its not easy to work out what your problem is, but i can say for sure a While Loop and DoEvents is not the way forward at all.
Instead raise an event when the thread has done all its work, subscribe to the event, and when it is raise close the form (if autoclose = true):
Public Class Form1
Public Event threadCompleted()
Public Sub New()
InitializeComponent()
AddHandler threadCompleted, AddressOf Me.Thread_Completed
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim t1 As New Threading.Thread(AddressOf mithread)
t1.Start()
End Sub
Public Sub mithread()
'simulate some work:
Threading.Thread.Sleep(3000)
'then raise the event when done
RaiseEvent threadCompleted()
End Sub
Public Delegate Sub Thread_CompletedDelegate()
Private Sub Thread_Completed()
If Me.InvokeRequired Then
Me.BeginInvoke(New Thread_CompletedDelegate(AddressOf Thread_Completed))
Else
If autoclose.Checked = True Then
Me.Close()
End If
End If
End Sub
End Class
Or use a background worker which does all this, plus handles reporting progress and cancelation all for you.

Answer 2

Sounds like something is happening in mithread that is preventing the thread from fully starting. I ran similar code with an empty sub for mithread and I get the expected threadstate (Stopped then Aborted).
Sub Main()
Dim thread_1 As System.Threading.Thread = New Threading.Thread(AddressOf mithread)
thread_1.Start()
System.Threading.Thread.Sleep(100)
While Not thread_1.ThreadState = Threading.ThreadState.Running
Console.WriteLine(thread_1.ThreadState.ToString)
thread_1.Abort()
Console.WriteLine(thread_1.ThreadState.ToString)
If thread_1.ThreadState = Threading.ThreadState.Aborted Then Exit While
End While
End Sub
Sub mithread()
End Sub