Dave,

You can change the width of the combobox via its Size property, but you
cannot change the height of the combobox. The width depend on the font used
to print the items. The bigger the font, the taller the combobox.
If you want to have control over the combobox height you need to implement
owner-draw combobox. In this case you can set the ItemHeight property.

If you want change the width of the combobox depending on the lenght of the
text you can measure the text using a graphics object created from the
combobox control. You need to take into cosideration the pull-down button. I
believe it is related to the size of the scroll bart thus you can use
SystemInformation.VerticalScrollBarWidth.

Try this:

   Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MyBase.Load

       With ComboBox1.Items
           .Clear()
           .Add("AAA")
           .Add("BBBBBB")
           .Add("CCCCCCCCC")
           .Add("DDDDDDDDDDDD")
           .Add("EEEEEEEEEEEEEEE")
           .Add("WWWWWWWWWWWWWWWWWWWWWW1")
       End With

       With ComboBox1
           Dim g As Graphics = ComboBox1.CreateGraphics
           Try
               For index As Integer = 0 To .Items.Count - 1
                   Dim size As SizeF = g.MeasureString(.Items(index), .Font)
                   size.Width += SystemInformation.VerticalScrollBarWidth
                   If .Width < size.Width Then .Width = size.Width
               Next
           Finally
               g.Dispose()
           End Try
       End With

   End Sub

I hope this helps,

Joris