Visual Basic.NET - aprendiz ado.net

Imports System.Data.SqlClient

Public Class Conexión

Function registro(ByVal sqla As String) As String

        Dim s As String = ""

        Try

            Dim cmdrea As New SqlCommand(sqla, conexion)

            Dim numfila As Integer

            'numfila numero de filas afectadas

            conexion.Open()

            numfila = cmdrea.ExecuteNonQuery() 'es una funcion devuelve el numero de filas afectadas int

            conexion.Close()

            If numfila > 0 Then

                s = "si"

            End If

        Catch ex As Exception

            conexion.Close()

        End Try

        Return s

    End Function

End Class

    Dim conexion As New SqlConnection("Data Source=.; Initial Catalog=diseños; Integrated Security=true")

''usar la coenxion

 Dim miclase As New Conexion

    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click

        Dim s As String = ""

        s = miclase.registro("insert into trabajadores values('" & t1.Text & "','" & t2.Text & "','" & t3.Text & "','" & t4.Text & "','" & t5.Text & "','" & t6.Text & "','" & t7.Text & "','" & t8.Text & "')")

        If s = "si" Then

            MsgBox("Datos registrados correctamente", MsgBoxStyle.Critical, "Aviso")

        Else

        End If

    End Sub