Entity framework 如何创建自定义的可重用DBContext

三类：

• CustomDbContext
• 可重用上下文
• DbContext

关系：

• 可重用上下文：DbContext
• CustomDbContext:可重用上下文

代码：

然后我尝试像这样重用ReusableContext：

public class CustomDbContext : ReusableDbContext
{
    public CustomDbContext() 
        : base()
    {
        Database.SetInitializer＜CustomDbContext＞(new 
MigrateDatabaseToLatestVersion＜CustomDbContext, CustomMigrationsConfiguration＞());
    }

    public DbSet＜CustomTable＞ CustomTables{ get; set; }
}

public class CustomMigrationsConfiguration : DbMigrationsConfiguration＜CustomDbContext＞
{
    public CustomMigrationsConfiguration()
        : base()
    {
        AutomaticMigrationsEnabled = true;
        AutomaticMigrationDataLossAllowed = true;
    }

    protected override void Seed(CustomDbContext context)
    {
        //CustomMigrationsConfiguration Seed Logic
        // this Seed method is called, no problem here
    }
}

public class CustomDbContext : ReusableDbContext
{
    public CustomDbContext() 
        : base()
    {
        Database.SetInitializer＜CustomDbContext＞(new 
MigrateDatabaseToLatestVersion＜CustomDbContext, CustomMigrationsConfiguration＞());
    }

    public DbSet＜CustomTable＞ CustomTables{ get; set; }
}

public class CustomMigrationsConfiguration : ReusableMigrationsConfiguration＜CustomDbContext＞
{
    public CustomMigrationsConfiguration()
        : base()
    {
        AutomaticMigrationsEnabled = true;
        AutomaticMigrationDataLossAllowed = true;
    }

    protected override void Seed(CustomDbContext context)
    {
        base.Seed(context);



        //CustomMigrationsConfiguration Seed Logic
        // this Seed method is called and OK
    }
}

项目运行后：

• 创建了ReusableTable和CustomTable
• 调用CustomMigrationConfiguration的种子方法并确定
• 但是，ReusableMigrationConfiguration的种子方法并没有被调用-----怎么了

这样做会有用的

public class CustomMigrationsConfiguration : DbMigrationsConfiguration＜CustomDbContext＞
{
    public ReusableMigrationsConfiguration()
        : base()
    {
        AutomaticMigrationsEnabled = true;
        AutomaticMigrationDataLossAllowed = true;
    }

    protected override void Seed(CustomDbContext context)
    {
        //CustomMigrationsConfiguration Seed Logic
        // this Seed method is called, no problem here
    }
}

---

问题解决了，这是解决办法

类别：

• CustomDbContext、CustomMigrationConfiguration
• ReusableContext，ReusableMigrationConfiguration＜TContext＞
• DbContext

关系：

• 可重用上下文：DbContext
• 可重用迁移配置＜TContext＞DbMigrationsConfiguration＜TContext＞ 其中TContext:ReusableContext
• CustomDbContext:可重用上下文
• CustomMigrationConfiguration:ReusableMigrationConfiguration＜CustomDbContext＞

代码：

现在我们可以像这样重用ReusableContext：

public class CustomDbContext : ReusableDbContext
{
    public CustomDbContext() 
        : base()
    {
        Database.SetInitializer＜CustomDbContext＞(new 
MigrateDatabaseToLatestVersion＜CustomDbContext, CustomMigrationsConfiguration＞());
    }

    public DbSet＜CustomTable＞ CustomTables{ get; set; }
}

public class CustomMigrationsConfiguration : DbMigrationsConfiguration＜CustomDbContext＞
{
    public CustomMigrationsConfiguration()
        : base()
    {
        AutomaticMigrationsEnabled = true;
        AutomaticMigrationDataLossAllowed = true;
    }

    protected override void Seed(CustomDbContext context)
    {
        //CustomMigrationsConfiguration Seed Logic
        // this Seed method is called, no problem here
    }
}

public class CustomDbContext : ReusableDbContext
{
    public CustomDbContext() 
        : base()
    {
        Database.SetInitializer＜CustomDbContext＞(new 
MigrateDatabaseToLatestVersion＜CustomDbContext, CustomMigrationsConfiguration＞());
    }

    public DbSet＜CustomTable＞ CustomTables{ get; set; }
}

public class CustomMigrationsConfiguration : ReusableMigrationsConfiguration＜CustomDbContext＞
{
    public CustomMigrationsConfiguration()
        : base()
    {
        AutomaticMigrationsEnabled = true;
        AutomaticMigrationDataLossAllowed = true;
    }

    protected override void Seed(CustomDbContext context)
    {
        base.Seed(context);



        //CustomMigrationsConfiguration Seed Logic
        // this Seed method is called and OK
    }
}

项目运行后：

• 创建可重用表和自定义表
• 调用CustomMigrationConfiguration的种子方法并确定
• 调用ReusableMigrationConfiguration的种子方法，也可以

---

现在一切似乎都很好：）

@Eranga@SONOFGOD我在这里看不到任何区别，请注意CustomDbContext类是从ReusableDbContext而不是DbContext扩展的。我打算做的是尝试重用ReusableDbContext（创建公共表的代码优先方法）和ReusableMigrationConfiguration的逻辑（用于创建视图、存储过程等的种子逻辑），可能将它们放在一个单独的项目中。在CustomDbContext中，您可以定义自己的表…通过从ReusableDbContext扩展，您可以将工作保存到创建这些公共表和其他公共数据库对象。我的问题是，ReusableMigrationConfiguration的种子方法从未调用，因此视图、存储过程或不可创建。

public class CustomDbContext : ReusableDbContext
{
    public CustomDbContext() 
        : base()
    {
        Database.SetInitializer＜CustomDbContext＞(new 
MigrateDatabaseToLatestVersion＜CustomDbContext, CustomMigrationsConfiguration＞());
    }

    public DbSet＜CustomTable＞ CustomTables{ get; set; }
}

public class CustomMigrationsConfiguration : ReusableMigrationsConfiguration＜CustomDbContext＞
{
    public CustomMigrationsConfiguration()
        : base()
    {
        AutomaticMigrationsEnabled = true;
        AutomaticMigrationDataLossAllowed = true;
    }

    protected override void Seed(CustomDbContext context)
    {
        base.Seed(context);



        //CustomMigrationsConfiguration Seed Logic
        // this Seed method is called and OK
    }
}