將實體框架與 Sql 服務器精簡版一起使用，無需添加 App.Config

Question

我正在為 Rhinoceros 6 開發一個插件，並且到目前為止對 Rhinoceros 的 App.Config 文件進行編輯似乎是不可能的。 插件項目的 App.Config 對 Rhinoceros 的 App.Config 沒有影響。

出現以下錯誤消息是因為我無法將提供程序和參數添加到 App.Config 的entityFramework部分。

Unable to determine the provider name for provider factory of type 'System.Data.SqlServerCe.SqlCeProviderFactory'. Make sure that the ADO.NET provider is installed or registered in the application config.

我用 NuGet 安裝了 EntityFramework.SqlServer.Compact 和 Microsoft.SqlServer.Compact 並檢查了參考資料，一切似乎都很好。

下面是我的代碼優先 dbcontext class：

        public class ModelLocalClipper : DbContext
    { 
        public ModelLocalClipper()
            : base(new SqlCeConnection("Data Source="+ Environment.GetFolderPath(Environment.SpecialFolder.Desktop)+"\\MyDatabase.sdf;Persist Security Info=False;"),
  contextOwnsConnection: true)
        {
            Database.SetInitializer<ModelLocalClipper>(new CreateDatabaseIfNotExists<ModelLocalClipper>());
        }
        
        public DbSet<Scene> Scenes { get; set; }
        public DbSet<LocalProject> LocalProjects { get; set; }
    }

    public class Scene
    {
        public int SceneId { get; set; }
        public string Name { get; set; }

        public int LocalProjectId { get; set; }

        [ForeignKey("LocalProjectId")]
        public virtual LocalProject LocalProject { get; set; }
    }

    public class LocalProject
    {
        public int LocalProjectId { get; set; }
        public string Name { get; set; }

        public virtual ICollection<Scene> Scenes { get; set; }
    }

搜索了一段時間后，我找到了這個解決方案並將其轉換為用於 SqlCe，如下所示，但它也沒有幫助

public class SqlCeProviderInvariantName : IProviderInvariantName
        {
            public static readonly SqlCeProviderInvariantName Instance = new SqlCeProviderInvariantName();
            private SqlCeProviderInvariantName() { }
            public const string ProviderName = "System.Data.SqlServerCe.4.0";
            public string Name { get { return ProviderName; } }
        }

    class SqlCeDbProviderFactoryResolver : IDbProviderFactoryResolver
    {
        public static readonly SqlCeDbProviderFactoryResolver Instance = new SqlCeDbProviderFactoryResolver();
        private SqlCeDbProviderFactoryResolver() { }
        public DbProviderFactory ResolveProviderFactory(DbConnection connection)
        {
            if (connection is SqlCeConnection) return SqlCeProviderFactory.Instance;
            if (connection is EntityConnection) return EntityProviderFactory.Instance;
            return null;
        }
    }

    class SqlCeDbDependencyResolver : IDbDependencyResolver
    {
        public object GetService(Type type, object key)
        {
            if (type == typeof(IProviderInvariantName)) return SqlCeProviderInvariantName.Instance;
            if (type == typeof(DbProviderFactory)) return SqlCeProviderFactory.Instance;
            if (type == typeof(IDbProviderFactoryResolver)) return SqlCeDbProviderFactoryResolver.Instance;
            return SqlCeProviderServices.Instance.GetService(type);
        }

        public IEnumerable<object> GetServices(Type type, object key)
        {
            var service = GetService(type, key);
            if (service != null) yield return service;
        }
    }

    class SqlCeDbConfiguration : DbConfiguration
    {
        public SqlCeDbConfiguration()
        {
            AddDependencyResolver(new SqlCeDbDependencyResolver());
        }
    }

版本：-RhinoCommon 6.30.20288.16410 -.NET Framework 4.8 -EntityFramework 6.4.4 -SqlServerCe.4.0

使用 ErikEJ 的指令，它起作用了：對於那些想要查看代碼的人來說，這里是 repo： https://github.com/Tahirhan/RhinoPluginSqlCECodeFirst

謝謝！

Answer 1

試試這個（更簡單的）方法，我可以使用控制台應用程序來實現它：

public class SqlCeDbConfiguration : DbConfiguration 
{
    public SqlCeDbConfiguration()
    {
        SetProviderServices(
            SqlCeProviderServices.ProviderInvariantName,
            SqlCeProviderServices.Instance);

        SetDefaultConnectionFactory(
            new SqlCeConnectionFactory(SqlCeProviderServices.ProviderInvariantName));
    }
}

接着：

[DbConfigurationType(typeof(SqlCeDbConfiguration))]
public class ModelSqlCECodeFirst : DbContext

Answer 2

正如這個答案所建議的那樣，對於 SQLite 方案，請嘗試此DbConfiguration並且不要忘記刪除“|DataDirectory|” 連接字符串的一部分

public class SQLiteConfiguration : DbConfiguration
{
    public SQLiteConfiguration()
    {
        SetProviderFactory("System.Data.SQLite", SQLiteFactory.Instance);
        SetProviderFactory("System.Data.SQLite.EF6", SQLiteProviderFactory.Instance);
        SetProviderServices("System.Data.SQLite", (DbProviderServices)SQLiteProviderFactory.Instance.GetService(typeof(DbProviderServices)));
    }
}