文件结构
ab
模型
ToDoItem
/// <summary>
/// This is our Model for a simple ToDoItem.
/// </summary>
public class ToDoItem
{
/// <summary>
/// Gets or sets the checked status of each item
/// </summary>
public bool IsChecked { get; set; }
/// <summary>
/// Gets or sets the content of the to-do item
/// </summary>
public string? Content { get; set; }
}服务
ToDoListFileService
包含创建，加载，保存三个方法
public static class ToDoListFileService
{
// This is a hard coded path to the file. It may not be available on every platform. In your real world App you may
// want to make this configurable
private static string _jsonFileName =
Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData),
"Avalonia.SimpleToDoList", "MyToDoList.txt");
/// <summary>
/// 保存list 到文件中 Stores the given items into a file on disc
/// </summary>
/// <param name="itemsToSave">The items to save</param>
public static async Task SaveToFileAsync(IEnumerable<ToDoItem> itemsToSave)
{
// Ensure all directories exists
Directory.CreateDirectory(Path.GetDirectoryName(_jsonFileName)!);
// We use a FileStream to write all items to disc
using (var fs = File.Create(_jsonFileName))
{
await JsonSerializer.SerializeAsync(fs, itemsToSave);
}
}
/// <summary>
/// Loads the file from disc and returns the items stored inside
/// </summary>
/// <returns>An IEnumerable of items loaded or null in case the file was not found</returns>
public static async Task<IEnumerable<ToDoItem>?> LoadFromFileAsync()
{
try
{
// We try to read the saved file and return the ToDoItemsList if successful
using (var fs = File.OpenRead(_jsonFileName))
{
return await JsonSerializer.DeserializeAsync<IEnumerable<ToDoItem>>(fs);
}
}
catch (Exception e) when (e is FileNotFoundException || e is DirectoryNotFoundException)
{
// In case the file was not found, we simply return null
return null;
}
}
}视图模型
MainViewModel 主窗口包含的模型
ToDoItemViewModel 单个待办项目模型
ViewModelBase：视图横型基类
视图
MainWindow视图