windows store gridview filtering???

Question

I am using semantic zoom and in the "zoom in" there are groceries of all kind

 

---

foodList = new List<Food>();

foodList.Add(new Food() { ClassName = "Dairy products", FoodName = "Milk", Calories = "kCal = 66" });

foodList.Add(new Food() { ClassName = "Dairy products",FoodName = "Sour Cream", Calories = "kCal = 127", });

foodList.Add(new Food() { ClassName = "Dairy products",FoodName = "Kefir", Calories = "kCal = 63", });

foodList.Add(new Food() { ClassName = "Dairy products",FoodName = "Fruit yogurt", Calories = "kCal = 34", });

foodList.Add(new Food() { ClassName = "Dairy products",FoodName = "Yogurt", Calories = "kCal = 40" });

foodList.Add(new Food() { ClassName = "Dairy products", FoodName = "Chocolate puding", Calories = "kCal = 134" });

foodList.Add(new Food() { ClassName = "Dairy products", FoodName = "Ice cream", Calories = "kCal = 205" });

---

i need help for

 

private void tb1_TextChanged(object sender, TextChangedEventArgs e)

{

         //as i write the gridview is showing me the items that contains inserted text

}

 

here's XAML...

 

<Grid.RowDefinitions>

<RowDefinition Height="Auto"/>

<RowDefinition Height="*"/>

</Grid.RowDefinitions>

<ContentPresenter ContentTemplate="{TemplateBinding ContentTemplate}" Content="{TemplateBinding Content}" Margin="{TemplateBinding Padding}"/>

<ItemsControl x:Name="ItemsControl" ItemsSource="{Binding GroupItems}" Grid.Row="1"/>