MvvmCross SQLite插件不适用于UWP项目 [英] MvvmCross SQLite Plugin not working for UWP Project

问题描述

当我尝试运行我的UWP项目时出现以下错误:

I am getting the following error when I try to run my UWP project:

MvvmCross.Platform.Exceptions.MvxIoCResolveException:'失败 为类型的参数工厂解析参数 创建时IMvxSqliteConnectionFactory DebtBuddy.Core.Repositories.AccountRepository'

MvvmCross.Platform.Exceptions.MvxIoCResolveException: 'Failed to resolve parameter for parameter factory of type IMvxSqliteConnectionFactory when creating DebtBuddy.Core.Repositories.AccountRepository'

我的android项目运行没有问题.以下是我的存储库类.

My android project runs with no problems. The following is my repository class.

 public class AccountRepository : IAccountRepository
{
    private readonly SQLiteConnection _connection;

    public AccountRepository(IMvxSqliteConnectionFactory factory)
    {
        _connection = factory.GetConnection("Account.db");
        _connection.CreateTable<Account>();
    }

    public async Task<List<Account>> GetAllAccounts()
    {
        return await Task.FromResult(_connection.Table<Account>().ToList());
    }

    public async Task Insert(Account account)
    {
        await Task.Run(() => _connection.Insert(account));
    }

    public async void Update(Account account)
    {
        await Task.FromResult(_connection.Update(account));
    }

    public async void Delete(int id)
    {
        await Task.FromResult(_connection.Delete(id));
    }
}

推荐答案

由于不推荐使用MvvmCross SQLite插件，因此您应该远离使用它.我还建议您使用SQLiteAsyncConnection将所有操作包装在Task内，类似于您在此处所做的操作.

You should move away from using this since the MvvmCross SQLite Plugin was deprecated. I'd also recommend using SQLiteAsyncConnection which wraps all the operations inside a Task similar to what you did here.

如今，首选的SQLite软件包称为sqlite-net-pcl，可在 NuGet中获得和 GitHub .该版本的库支持Android Nougat和更高版本，并且以最新版本的.Net Standard为目标.

The preferred SQLite package these days is called sqlite-net-pcl, which is available on NuGet and GitHub. This version of the library supports Android Nougat and later, and targets .Net Standard in the most recent versions.

MvvmCross SQLite包装器只是围绕SQLite的较小包装器.自己复制MvvmCross SQLite插件很容易.这是一个这样的例子:

The MvvmCross SQLite wrapper was just a smaller wrapper around SQLite. It's easy to reproduce the MvvmCross SQLite Plugin on your own. Here is one such example:

将此接口放在您的PCL/.Net Standard核心"项目中:

Put this interface in your PCL/.Net Standard "Core" project:

public interface ISqliteConnectionService
{
    SQLiteAsyncConnection GetAsyncConnection();
}

然后为每个平台实现接口.这是Android的外观.抱歉，我手边没有UWP示例.

Then you implement the interface for each platform. Here is what it would look like for Android. I'm sorry, I don't have a UWP example on hand.

public class AndroidSqliteConnectionService : ISqliteConnectionService
{
    private const string FileName = "File.sqlite3";
    private SQLiteAsyncConnection _connection;

    public SQLiteAsyncConnection GetAsyncConnection()
    {
        if (_connection == null)
        {
            var databaseFolder = Environment.GetFolderPath(Environment.SpecialFolder.Personal);
            var databaseFilePath = Path.Combine(databaseFolder, FileName);
            _connection = new SQLiteAsyncConnection(databaseFilePath);
        }
        return _connection;
    }
}

然后在每个平台的Setup.cs中注册实现:

Then register the implementation in the Setup.cs of each platform:

protected override void InitializeFirstChance()
{
    Mvx.LazyConstructAndRegisterSingleton<ISqliteConnectionService, AndroidSqliteConnectionService>();
}

现在，您可以使用构造函数依赖注入在PCL/.Net Standard核心"项目中与ViewModel，存储库等共享ISqliteConnectionService.

Now you can use constructor Dependency Injection to share the ISqliteConnectionService with your ViewModels, Repositories, etc. inside of your PCL/.Net Standard "Core" project.

这篇关于MvvmCross SQLite插件不适用于UWP项目的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！