代码优先迁移表示有挂起的更改,而没有

所以我想运行 database update 在MVC 5中,在MVC操作中:

public async Task<ActionResult> UpdateDatabase(UpdateDatabaseModel updateDatabaseModel)
{
    DbMigrationsConfiguration migrationsConfiguration = new DbMigrationsConfiguration
    {
        TargetDatabase = new DbConnectionInfo("DefaultConnection"),
        ContextType = typeof(ApplicationDbContext),
        MigrationsAssembly = typeof(ApplicationDbContext).Assembly
    };

    var migrator = new DbMigrator(migrationsConfiguration);
    migrator.Update(updateDatabaseModel.SelectedMigration);
    return this.View("ManageApplication");
 }

问题是,在 migrator.Update(updateDatabaseModel.SelectedMigration); 它抛出一个错误:

无法更新数据库以匹配当前模型,因为存在挂起的更改,并且禁用了自动迁移。将挂起的模型更改写入基于代码的迁移或启用自动迁移。将DBMigrationsConfiguration.AutomaticMigrationsEnabled设置为true以启用自动迁移。

但当我做一个 add-migration , the Up() 和 Down() 是空的(在添加此迁移之后,它仍然抛出该异常)

知道吗?

我也检查过这个: EF Add-Migration indicates "No pending explicit migrations" but Update-Database complains "..there are pending changes" 但是名称空间没问题。