在独立存储中存储对象列表的问题 [英] problem Storing a list of Objects in Isolated Storage

问题描述

我正在尝试将我创建的对象列表存储在独立存储中，并能够通过自动为它们生成标题来将它们显示在列表中.到目前为止，代码有效，但是一旦我对应用程序进行墓碑删除并启动它，除了对象列表之外，我的所有数据都将被保存.我认为我的问题可能在于我如何初始化列表，或者可能是我如何显示名称.任何帮助表示赞赏.

I am trying to store a list of objects I created in the isolated storage and be able to display them in a list by auto generating a title for them. So far the code works but once I tombstone the app and start it up all my data is saved except for the list of objects. I think my problem may be with how I initialize the list in the first place, or possibly how I am displaying the names. Any help is appreciated.

此代码在我的 App.xaml.cs 中:

this code is in my App.xaml.cs:

public partial class App : Application
    {
      public List<my_type> testList = new List<my_type>();

        void loadvalues()
        {
         IsolatedStorageSettings settings = IsolatedStorageSettings.ApplicationSettings;
         List<my_Type> L;
         if (settings.TryGetValue<List<DrinkSesh>>("Storage", out L))
         { testList = L; }
        }

        void savevalues()
        {
        IsolatedStorageSettings settings = IsolatedStorageSettings.ApplicationSettings;
        settings["Storage"] = testList;
        settings.Save();
        }
     }

此代码在我的 mainPage 上，用于将项目添加到列表中:

This code is on my mainPage to add the items to the list:

(Application.Current as App).testList.Add(new my_type());

而这段代码是在不同页面的屏幕上实现标题:

and this code is to implement the titles onto the screen on a different page:

 public different_class()
{
        {
                InitializeComponent();
                for (i = 0; i < (Application.Current as App).testList.Count; i++)
                {
                    CreateATextBlock((Application.Current as    App).testList[i].Title_ToString(), i);
                }
        }

        private void CreateATextBlock(String title,int num)
        {
            testblockname = new TextBlock();
            testblockname.Text = (num + 1) + ". " + title;
            DrList.Children.Add(testblockname);
        }
}

先谢谢你！

推荐答案

这是我用来从独立存储中保存和加载对象列表的代码.

Here is the code I use to save and load lists of objects from isolated storage.

public class IsoStoreHelper
{
    private static IsolatedStorageFile _isoStore;
    public static IsolatedStorageFile IsoStore 
    { 
        get { return _isoStore ?? (_isoStore = IsolatedStorageFile.GetUserStoreForApplication()); }
    }

    public static void SaveList<T>(string folderName, string dataName, ObservableCollection<T> dataList) where T : class
    {
        if (!IsoStore.DirectoryExists(folderName))
        {
            IsoStore.CreateDirectory(folderName);
        }

        string fileStreamName = string.Format("{0}\{1}.dat", folderName, dataName);

        using (IsolatedStorageFileStream stream = new IsolatedStorageFileStream(fileStreamName, FileMode.Create, IsoStore))
        {
            DataContractSerializer dcs = new DataContractSerializer(typeof(ObservableCollection<T>));
            dcs.WriteObject(stream, dataList);
        }
    }

    public static ObservableCollection<T> LoadList<T>(string folderName, string dataName) where T : class
    {
        ObservableCollection<T> retval = new ObservableCollection<T>();

        if (!IsoStore.DirectoryExists(folderName))
        {
            IsoStore.CreateDirectory(folderName);
        }

        string fileStreamName = string.Format("{0}\{1}.dat", folderName, dataName);

        using (IsolatedStorageFileStream stream = new IsolatedStorageFileStream(fileStreamName, FileMode.OpenOrCreate, IsoStore))
        {
            if (stream.Length > 0)
            {
                DataContractSerializer dcs = new DataContractSerializer(typeof(ObservableCollection<T>));
                retval = dcs.ReadObject(stream) as ObservableCollection<T>;
            }
        }

        return retval;
    }
}

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