本文介绍了如何以编程方式选择DbConfigurationType?的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我有一个 DbContext :
[DbConfigurationType(typeof(MySqlEFConfiguration))] public class MyDbContext : DbContext { public DbSet<MyClass> MyClasses { get; set; } }现在,如果我想根据AppSettings的值使用另一个 DbConfigurationType ,该怎么办?
Now, what if I want to be able to use another DbConfigurationType, according to AppSettings value?
因此,我将AppSettings值从 MySQL 更改为 MSSQL ,它变为:
So that, I change AppSettings value from MySQL to MSSQL and it becomes:
[DbConfigurationType(typeof(MsSqlEFConfiguration))] public class MyDbContext : DbContext { public DbSet<MyClass> MyClasses { get; set; } }当然,我可以创建一个工厂,并使用反射来创建一个具有自定义属性的新类.但是,有没有解决的办法吗?
Of course, I can create a factory, and use reflection to create a new class with custom attribute. However, is there a solution without reflection?
推荐答案我已经通过继承 DbConfigurationTypeAttribute
public class BaseEfConfiguration : DbConfigurationTypeAttribute { public BaseEfConfiguration() : base(SqlConfiguration) { } public static Type SqlConfiguration { get { string databaseTypeName = ConfigurationManager.AppSettings["DatabaseType"]; switch (databaseTypeName) { case "MySQL": return typeof(MySqlEFConfiguration); case "MSSQL": return typeof(MsSqlEFConfiguration); default: throw new NotImplementedException($"No such SQL configuration type {databaseTypeName}"); } } } } [BaseEfConfiguration] public class BaseDbContext : DbContext { }更多推荐
如何以编程方式选择DbConfigurationType?
发布评论