Question

How do I get the SuspendLayout and ResumeLayout to work correctly in regards to a listview. I have added these lines of code before and after I have added the items, yet each item is still being displayed as I add each item.

thanks

• My code:

      Dim x As Integer
  
  Dim startTick As Integer = Environment.TickCount
  
  lstFiles.SuspendLayout()
  
  For x = 0 To UBound(cacheListArray)
      If cacheListArray(x) Like "*.txt" Then
          lstFiles.Items.Add(cacheListArray(x))
      End If
  Next
  
  lstFiles.ResumeLayout()
  
  MsgBox(Environment.TickCount - startTick)
  

I am adding 2000 items. This takes 7 seconds. I was told that it should be a lot shorter than that. Is that correct?

---

New code:

        Dim ListViewItemArray(-1) As ListViewItem

                ReDim Preserve ListViewItemArray(UBound(ListViewItemArray) + 1)
            ListViewItemArray(UBound(ListViewItemArray)).Text = file.Name
            ListViewItemArray(UBound(ListViewItemArray)).SubItems.Add(file.FullName)
            ListViewItemArray(UBound(ListViewItemArray)).SubItems.Add(file.Length)
            ListViewItemArray(UBound(ListViewItemArray)).SubItems.Add(file.CreationTime)
            ListViewItemArray(UBound(ListViewItemArray)).SubItems.Add(file.LastWriteTime)
            ListViewItemArray(UBound(ListViewItemArray)).SubItems.Add(file.LastAccessTime)

        lstFiles.Items.AddRange(ListViewItemArray)

Nothing is being added. What have I done incorrectly?

Answer 1

You are using the wrong method. The Suspend/ResumeLayout() methods are only appropriate for container controls whose child controls you want to move around without them getting repainted while you are doing so. You never give ListView any child controls.

Use the Begin/EndUpdate() methods instead.