ASP.NET - obtener datos datagridview

//int i = int.Parse(grid.SelectedRow.Cells[0].Text);

int i = 5;

string s = System.Configuration.ConfigurationManager.ConnectionStrings["cadenaconexion"].ConnectionString;

SqlConnection conexion = new SqlConnection(s);

conexion.Open();

SqlCommand comando = new SqlCommand("delete from usuarios where id= '" + i + "'", conexion);

comando.ExecuteNonQuery();

SqlDataAdapter adaptador = new SqlDataAdapter();

adaptador.SelectCommand = comando;

DataTable tabla = new DataTable();

adaptador.Fill(tabla);

grid.DataSource = tabla;

grid.DataBind();

Dim ID as integer = Me.GridView1.Rows(GridView1.SelectedRow.RowIndex).Cells(1).Text

Dim Cnn As New SqlConnection(CONEXION)

Dim sentencia As String = "delete from TABLA where CAMPO_ID = '" & ID & "'"

Dim comando As New SqlClient.SqlCommand(sentencia, Cnn)

Dim resultados As Integer

Cnn.Open()

resultados = comando.ExecuteNonQuery()

Cnn.Close()