How to change/modify images in ListView

Question

After adding image to a listview, how can we change them. I tried the follwong but did not work. Please advise.

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Dim lvItem1 As New ListViewItem

lvItem1.ImageIndex = intImageIndex  

If str_Status = "U" Then 'Update text and image in listview

    lv_Messages.Items(intRow).Text = strTimeStamp   ' This works OK

    Me.lv_Messages.Invalidate(lv_Messages.Bounds)

    Me.lv_Messages.Update()

End If