I am using semantic zoom and in the "zoom in" there are groceries of all kind
 
foodList = new List();
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...