private void txt_procurar_Material_TextChanged(object sender, TextChangedEventArgs e)
 {
     if (txt_procurar_Material.Text.Length > 0)
     {
         this.Material_Todas_listBox.DisplayMemberPath = "nome_material";
         this.Material_Todas_listBox.SelectedValuePath = "id_material";
         this.Material_Todas_listBox.ItemsSource       = materialBLL.ConsultarMaterialPeloNome(txt_procurar_Material.Text);
     }
     else
     {
         CarregarListboxMaterial();
     }
 }