private void navigationHelper_LoadState(object sender, LoadStateEventArgs e)
{
// TODO: 将可绑定项集合分配到 this.DefaultViewModel["Items"]
card = e.NavigationParameter as MenuCard;
if(card != null)
{
this.DefaultViewModel["Items"] = card.MenuItems;
}
}
public MenuCardData(MenuCard menuCard)
{
this.Title = menuCard.Title;
this.Description = menuCard.Description;
this.ImagePath = menuCard.ImagePath;
MenuItems = new List<MenuItemData>();
foreach (var item in menuCard.MenuItems)
{
MenuItems.Add(new MenuItemData(item));
}
}
// 写数据到文件
public async Task WriteMenuCardAsync(MenuCard menuCard)
{
StorageFolder folder = ApplicationData.Current.RoamingFolder;
if (menuCard.IsDirty)
{
StorageFile storageFile = await folder.CreateFileAsync(
string.Format("MenuCards{0}.xml", menuCard.Title),
CreationCollisionOption.ReplaceExisting);
await WriteMenuCardToFileAsync(menuCard, storageFile);
menuCard.ClearDirty();
}
}
public MenuCard ToMenuCard()
{
var menuCard = new MenuCard
{
Title = this.Title,
Description = this.Description,
ImagePath = this.ImagePath
};
foreach (MenuItemData item in this.MenuItems)
{
menuCard.MenuItems.Add(item.ToMenuItem());
}
menuCard.ClearDirty();
return menuCard;
}
public async Task WriteMenuCardToFileAsync(MenuCard menuCard, StorageFile storageFile)
{
var menuCardData = new MenuCardData(menuCard);
var knownTypes = new Type[]
{
typeof(MenuItemData)
};
var cardStream = new MemoryStream();
var serializer = new DataContractSerializer(typeof(MenuCardData), knownTypes);
serializer.WriteObject(cardStream, menuCardData);
using (Stream fileStream = await storageFile.OpenStreamForWriteAsync())
{
cardStream.Seek(0, SeekOrigin.Begin);
await cardStream.CopyToAsync(fileStream);
await fileStream.FlushAsync();
}
}
public static ObservableCollection<MenuCard> GetSampleMenuCards()
{
Uri baseUri = new Uri("ms-appx:///");
var cards = new ObservableCollection<MenuCard>();
var card1 = new MenuCard
{
Title = "Breakfast"
};
card1.MenuItems.Add(new MenuItem
{
Text = "Spezialfrühstück",
Price = 5.4,
MenuCard = card1
});
card1.MenuItems.Add(new MenuItem
{
Text = "Wiener Frühstück",
Price = 4.4,
MenuCard = card1
});
card1.MenuItems.Add(new MenuItem
{
Text = "Schinken mit 3 Eiern",
Price = 4.4,
MenuCard = card1
});
card1.ImagePath = string.Format("{0}{1}", baseUri, "Assets/Breakfast.jpg");
cards.Add(card1);
var card2 = new MenuCard
{
Title = "Salad"
};
card2.MenuItems.Add(new MenuItem
{
Text = "Mariniertes Gemüse mit Schafkäsebällchen und Rohschinken",
Price = 8.60,
MenuCard = card2
});
card2.MenuItems.Add(new MenuItem
{
Text = "Gebratener Schafkäse im Speckhemd auf knackigem Salat",
Price = 7.80,
MenuCard = card2
});
card2.MenuItems.Add(new MenuItem
{
Text = "Backhendlsalat",
Price = 7.20,
MenuCard = card2
});
card2.ImagePath = string.Format("{0}{1}", baseUri, "Assets/Salads.jpg");
cards.Add(card2);
var card3 = new MenuCard
{
Title = "Sweets"
};
card3.MenuItems.Add(new MenuItem
{
Text = "Marillenknödel mit Zimtbrösel (Stück)",
Price = 2.30,
MenuCard = card3
});
card3.MenuItems.Add(new MenuItem
{
Text = "Apfelstrudel",
Price = 2.60,
MenuCard = card3
});
card3.MenuItems.Add(new MenuItem
{
Text = "Marmelade-Palatschinken (2 Stück)",
Price = 3.40,
MenuCard = card3
});
card3.ImagePath = string.Format("{0}{1}", baseUri, "Assets/Sweets.png");
cards.Add(card3);
return cards;
}
/// <summary>
/// 保留与此页关联的状态，以防挂起应用程序或
/// 从导航缓存中放弃此页。 值必须符合
/// <see cref="SuspensionManager.SessionState"/> 的序列化要求。
/// </summary>
///<param name="sender">事件的来源；通常为 <see cref="NavigationHelper"/></param>
///<param name="e">提供要使用可序列化状态填充的空字典
///的事件数据。</param>
///
// 退出页面时会调用 保存添加的Card
private async void navigationHelper_SaveState(object sender, SaveStateEventArgs e)
{
var mc = new MenuCard
{
Title = info.Title,
Description = info.Description,
Image = info.Image,
ImagePath = info.ImageFileName
};
MenuCardRepository.Instance.Cards.Add(mc);
var storage = new MenuCardStorage();
await storage.WriteMenuCardsAsync(MenuCardRepository.Instance.Cards.ToList());
}