Visual Basic.NET - ayuda con (INSTERTAR, MODIFICAR, ELIMINAR, BUSCAR) en Access

Module Conexion

    Public conexion As New OleDbConnection

    Public Sub conexiones()

        conexion.ConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=D:\DesarrolloNET\FVB_DataGridView\Estudiantes.accdb;"

        Try

            If conexion.State = ConnectionState.Open Then

                MessageBox.Show("Ya está conectado")

            Else

                conexion.Open()

                MessageBox.Show("Conectado a Access")

            End If

        Catch ex As Exception

            MessageBox.Show(ex.Message)

        End Try

    End Sub

End Module

Private Sub CargaGrid()

	Dim dt As New DataTable

	Dim da As New OleDb.OleDbDataAdapter

	Dim cmd As New OleDb.OleDbCommand

	Dim dr As OleDb.OleDbDataReader

	Dim col1 As New DataGridViewTextBoxColumn

	Dim col2 As New DataGridViewTextBoxColumn

	Dim fila(2) As String

	col1.Name = "ID"

	col1.HeaderText = "ID"

	DataGridView1.Columns.Add(col1)

	col2.Name = "Nombre"

	col2.HeaderText = "Nombre"

	DataGridView1.Columns.Add(col2)

	cmd.Connection = Conexion.conexion

	cmd.CommandText = "SELECT * from Estudiantes"

	cmd.CommandType = CommandType.Text

	dr = cmd.ExecuteReader()

	If dr.HasRows Then

		Do While dr.Read()

			MsgBox(dr(0).ToString)

			fila(0) = dr(0).ToString

			fila(1) = dr(1).ToString

			DataGridView1.Rows.Add(fila(0).ToString, fila(1).ToString)

		Loop

	End If

End Sub