Citação:
    
  Dim controle As Control

Public Function Testar_vazio(ByVal tela As Object) As Boolean
        Dim controle As Control
        Dim controle2 As Control
        For Each controle In tela.Controls
            If TypeOf controle Is TextBox Or TypeOf controle Is MaskedTextBox Or TypeOf controle Is DateTimePicker Or TypeOf controle Is CheckBox Or TypeOf controle Is ComboBox Or TypeOf controle Is TableLayoutPanel Or TypeOf controle Is DevExpress.XtraEditors.TextEdit Or TypeOf controle Is DevExpress.XtraEditors.ComboBoxEdit Then
                If controle.Text = "" And controle.Tag <> "x" Then
                    controle.Focus()
                    MessageBox.Show(controle.Name)
                    Return True
                End If

            ElseIf TypeOf controle Is GroupBox Or TypeOf controle Is DevExpress.XtraEditors.GroupControl Or TypeOf controle Is TextBox Or TypeOf controle Is MaskedTextBox Or TypeOf controle Is CheckBox Or TypeOf controle Is ComboBox Or TypeOf controle Is DevExpress.XtraEditors.TextEdit Or TypeOf controle Is DevExpress.XtraEditors.ComboBoxEdit Then
                For Each controle2 In controle.Controls
                    If controle2.Text = "" And controle2.Tag <> "x" Then
                        controle2.Focus()
                        MessageBox.Show(controle2.Name)
                        Return True
                    End If
                Next
            End If
        Next
    End Function