lisview topic that doesnt seem to be answered

[RRice]

In my program i have a listview..this listview has 8 columns,and at least 4000 entry's..now once the listview is filled i need to take whatever is in the last column for each line(in this case a file name) and perform various things on it..from downloading to crc32 calculations.
I'll concentrate on the crc32 since the code is more compact:
This is how i have it setup to grab the entry, add whatever directory it might be located in and then perform the calculations.

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
      
        Dim Temp As String, a As Long, Path as string
        On Error Resume Next ' because some file names might be missing
        For a = 0 To ListView1.Items.Count

            With ListView1.Items(a)

                Temp = Replace(.SubItems(8).Text, "/", "\") 
                sFileName = Path & Temp
                TextBox1.Text = GetCRC32(sFileName)

                Application.DoEvents()
                .SubItems(7).Text = TextBox1.Text
                ProgressBar1.Value = a * 100 / ListView1.Items.Count
                ' Call Sleep so the listview is briefly displayed, 
                'which will create a slide-show effect.
                System.Threading.Thread.Sleep(20)
            End With
        Next
    End Sub

So the problem is this,,i need to be able to scroll down the list without the process being stopped ..thus far whenever i click on the scrollbar the code stops until i release the mouse button..also if i click and hold at the top of my form the code also stops running.

I'm wondering if i need to use multithreading which I've never done before,,and if so how would i add it to the above code to make it work/solve the problem .

[Hack]

So the problem is this,,i need to be able to scroll down the list

Why? What is the purpose of the scrolling while the processing is going on?

[RRice]

because after a file is completed the word "Complete" is placed in the list, as well as color changes, the crc is all placed back to the list,also the list is editable so if a column is blank you can edit on the fly while downloading etc.
i need the listview to be completely free of any activity that might be going on elsewhere in the program,but be able to have a percentage of file downloaded going on in one of the columns,,like the download manager IDM no problems scrolling that list while a download is in progress

so do ya know how to fix the issue?