我有一个笔记应用程序，以前工作得很好，但重新打开应用程序后数据没有保存。我添加了SQLite来保存笔记，但现在应用程序卡在“.NET”紫色屏幕上，无法完成加载。

下面是我的.xaml.cs代码的简化版本：（“//...”表示与SQLite无关的代码）

namespace NotesApp;
using CommunityToolkit.Maui.Alerts;
using CommunityToolkit.Maui.Core;
using Microsoft.Maui.Controls;
using System;
using System.Threading;
using System.Threading.Tasks;
using SQLite;

public partial class MainPage : ContentPage
{
    // Define the SQLite database connection
    private SQLiteAsyncConnection _database;

    // Create the SQLite database and table
    private async Task CreateDatabaseAndTableAsync()
    {
        _database = new SQLiteAsyncConnection("notes.db3");

        // Create the table if it doesn't exist
        await _database.CreateTableAsync<Notes>();
    }

    private List<Notes> items; // Declare the items list at the class level

    public MainPage()
    {
        items = new List<Notes>() // Items I will delete after SQLlite
        {
            // ...
        };

        InitializeComponent();
        NotesView.ItemsSource = items;

        HelpLabel.IsVisible = items.Count == 0;

        // Initialize the SQLite database
        CreateDatabaseAndTableAsync().Wait();

        // Load notes from the SQLite database
        LoadNotesFromDatabase();

    }

    private async void LoadNotesFromDatabase()
    {
        // Fetch all notes from the SQLite database
        var notes = await _database.Table<Notes>().ToListAsync();

        // Update the items list with the loaded notes
        items.Clear();
        items.AddRange(notes);

        // Update the ItemsSource of NotesView to reflect the loaded items list
        NotesView.ItemsSource = null;
        NotesView.ItemsSource = items;

        HelpLabel.IsVisible = items.Count == 0;
    }

    private async void AddNoteButtonClicked(object sender, EventArgs e)
    {
        
        // ...

        // Create a new Notes object with the appropriate properties
        Notes newNote = new Notes { Id = items.Count + 1, Title = "New Note", Content = "Press ✏️ to add content." };

        // Add the new note to the SQLite database
        await _database.InsertAsync(newNote);

        // Add the new note to the items list
        items.Insert(0, newNote);

        // Update the ItemsSource of NotesView to reflect the updated items list
        NotesView.ItemsSource = null; // Clear the previous ItemsSource binding
        NotesView.ItemsSource = items; // Set the ItemsSource again with the updated list

        // ...

    }

    private async void DeleteButtonClicked(object sender, EventArgs e)
    {

        // ...

        if (noteToDelete != null)
        {
            // Remove the note from the SQLite database
            await _database.DeleteAsync(noteToDelete);

            // ...

            // Remove the note from the items list
            items.Remove(noteToDelete);

            // Update the ItemsSource of NotesView to reflect the updated items list
            NotesView.ItemsSource = null; // Clear the previous ItemsSource binding
            NotesView.ItemsSource = items; // Set the ItemsSource again with the updated list

            // ...
        }
    }

    // ...

    private async void EditButtonClicked(object sender, EventArgs e)
    {
        // ...

        if (noteToEdit == null)
            return;

        // ...

        if (noteToEdit != null)
        {
            // Update the note in the SQLite database
            await _database.UpdateAsync(noteToEdit);

            if (editButton.BackgroundColor == Colors.LightCyan)
            {
                // ...
            }
            else if (editButton.BackgroundColor == Colors.Gray)
            {
                // ...
            }



        }
        // ...
        

    }

}

字符串
我不知道为什么会这样。这可能与我在编码时做错了什么有关吗？任何帮助将不胜感激。先谢谢你了。