Creating A Combobox Containing Only Unique Distinct Alphabetically Sorted Values

Sometimes unique values need to fill the combobox and need to sort alphabetic..In this way, the processes may be easier.

The cells in Column A were selected to fill combobox in this example :
For x = 2 To Cells(Rows.Count, 1).End(xlUp).Row - "1" in the code indicates Column A.

Also,data is filtered with combobox and copied to the other pages in our study.

The used codes to fill combobox unique values and to sort alphabetic :

Dim x, a, b As Long, c As Variant

'Unique Records

For x = 2 To Cells(Rows.Count, 1).End(xlUp).Row

If WorksheetFunction.CountIf(Range("A2:A" & x), Cells(x, 1)) = 1 Then

ComboBox1.AddItem Cells(x, 1).Value

End If

Next

'Alphabetic Order

For a = 0 To ComboBox1.ListCount - 1

For b = a To ComboBox1.ListCount - 1

If ComboBox1.List(b) < ComboBox1.List(a) Then