protected void btn_Excluir_Click(object sender, EventArgs e)
 {
     try
     {
         Class_Vendedor vend = new Class_Vendedor();
         vend.matricula = txtmatricula.Text;
         vend.deletar();
     }
     catch (Exception ex)
     {
         Response.Write(ex.Message);
     }
 }
        protected void GridView1_RowDeleting(object sender, GridViewDeleteEventArgs e)
        {
            try
            {
                Class_Vendedor vend = new Class_Vendedor();
                vend.matricula = e.Values[0].ToString();
                vend.deletar();

                GridView1.EditIndex  = -1;
                GridView1.DataSource = vend.visualizar();
                GridView1.DataBind();
            }
            catch (Exception ex)
            {
                Response.Write(ex.Message);
            }
        }