Mã: Public Function LoaiBoDau(ByVal str As String) As String Dim regex As New Regex("\p{IsCombiningDiacriticalMarks}+") Dim strFormD As String = str.Normalize(System.Text.NormalizationForm.FormD).ToLower Return Trim(regex.Replace(strFormD, [String].Empty).Replace("đ", "d").Replace("Đ", "D")) End Function Chèn thêm thư viện Imports System.Text.RegularExpressions