WP8 - ObservarableCollection，无法更新列表框

Question

所以基本上我正在创建这个简单的笔记应用程序，它可以保存和添加笔记等。我现​​在遇到的问题是使用 ObservarableCollection 来更新所有已保存笔记出现的列表框。基本上，我单击一个按钮，它会将我带到一个页面，我可以在其中编写和保存我的笔记。现在当我点击保存时。笔记保存在一个目录中，当我返回列表框所在的主页时，通常将笔记加载到目录中，它是空的。因此，我将项目加载回列表框的唯一方法是退出应用程序然后再次启动它。这就是我现在遇到的问题。

我添加了 ObservableCollection。 FillListBox 显然是从 MainPage 中的 OnNavigatedTo 事件调用的。

到目前为止，这就是我所拥有的：

NoteTemplateList LoadNotes = new NoteTemplateList();

public void FillListBox()
{
    var frame = (PhoneApplicationFrame)Application.Current.RootVisual;
    var MainMenux = (MainMenu)frame.Content;

    MainMenux.lb1.ItemsSource = LoadNotes;
    MainMenux.lb2.ItemsSource = LoadNotes;
}

public class NoteTemp 
{        
    public string NoteT { get; set; }
    public string NoteB { get; set; }          
}

public class NoteTemplateList : ObservableCollection<NoteTemp>
{
    public NoteTemplateList()
    { 
        IsolatedStorageFile store = IsolatedStorageFile.GetUserStoreForApplication();
        store.CreateDirectory("/Pencil/Notes/");
        string directory = "/Pencil/Notes/";
        string[] filenames = store.GetDirectoryNames(directory);
        List<NoteTemplateList> dataSource = new List<NoteTemplateList>();
        foreach (string filename in filenames)
        {
            IsolatedStorageFileStream fileStream = store.OpenFile("/Pencil/Notes/" + filename + "/Title.txt", FileMode.Open, FileAccess.Read);
            IsolatedStorageFileStream fileStream1 = store.OpenFile("/Pencil/Notes/" + filename + "/Note.txt", FileMode.Open, FileAccess.Read);
            using (StreamReader readtitle = new StreamReader(fileStream))
            {
                var title = readtitle.ReadLine();
                using (StreamReader readbody = new StreamReader(fileStream1))
                {
                    var body = readbody.ReadLine();
                    Add(new NoteTemp { NoteT = title, NoteB = body, });
                }
            }
        }
    }
}

public class ItemProperties : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    public ItemProperties() { }

    private string m_NoteT;

    public string NoteT
    {
        get { return m_NoteT; }

        set
        {
            m_NoteT = value;
            OnPropertyChanged("NoteT");
        }
    }

    private string m_NoteB;

    public string NoteB
    {
        get { return m_NoteB; }
        set
        {
            m_NoteB = value;
            OnPropertyChanged1("NoteB");
        }
    }

    protected void OnPropertyChanged(string NoteT)
    {
        PropertyChangedEventHandler handler = this.PropertyChanged;
        if (handler != null)
            handler(this, new PropertyChangedEventArgs(NoteB));
    }

    protected void OnPropertyChanged1(string NoteB)
    {

        PropertyChangedEventHandler handler = this.PropertyChanged;
        if (handler != null)
            handler(this, new PropertyChangedEventArgs(NoteB));
    }
} 

在主页中：

protected override void OnNavigatedTo(NavigationEventArgs e)
{
    m.FillListBox();
}

将笔记加载到列表框中

Answer 1

在OnNavigatedTo 事件处理程序内的FillListBox 调用之前添加LoadNotes = new NoteTemplateList();。