在Breeze EFContextProvider中使用动态连接字符串(Using a dynamic connection string with the Breeze EFContextProvi

在Breeze EFContextProvider中使用动态连接字符串(Using a dynamic connection string with the Breeze EFContextProvider)

目前我有一个应用程序（web / silverlight），其中我的ObjectContext的连接字符串是动态的。 它基于用户如何登录，因为我的每个客户都有自己的数据库。 即..用户名@域。 我试图找到一种方法来使用EFContextProvider，它可以通过构造函数传递ObjectContext，也可以通过覆盖GetConnectionString，这两种方法都不被支持。

有没有办法做到这一点，或者我可以下载EFContextProvider的源代码，以便我可以自己实现它？

提前致谢。

这个问题是由Marcel在我们的IdeaBlade论坛发布的。 因为我认为这对Breeze Stack Overflow社区有用，所以我在此重新发布问题和答案。

At the moment i have an application (web/silverlight) where the connectionstring for my ObjectContext is dynamic. It is based on how a user logs in because each of my customers have their own database. ie.. username@domain. I'm trying to find a way to use the EFContextProvider which would be by either passing the ObjectContext through the constructor, or by overriding the GetConnectionString, which sadly both aren't supported.

Is there a way to accomplish this, or can i download the source for the EFContextProvider somewhere so i can implement it myself ?

Thanks in advance.

This question was posted by Marcel on our IdeaBlade forums. I am reposting the question and answer here since I think it will be useful to the Breeze Stack Overflow community.

最满意答案

您不必下载源代码并对其进行修改就可以实现这么简单的功能。 现在你不需要 。

我们已经推送给GitHub一个简单的更新到EFContextProvider 。 此更改将显示在下一个Breeze Runtime版本（> 0.81.2）中。

EFContextProvider用于创建'T'（您的ObjectContext / DbContext），如下所示：

_context = new T();

现在它调用一个虚方法T CreateContext() ，它的默认实现是：

protected virtual T CreateContext() { return new T(); }

覆盖并替换您的EFContextProvider子类中的内容，您将能够按照您喜欢的方式创建“T”类型的上下文。

注意：基础EFContextProvider仍然会进行一些后期创建配置 ，以确保它的行为符合我们的预期; 我们不希望上下文进行任何延迟加载或创建代理。

所以如果'T'是一个ObjectContext ，提供者将会这样做：

objCtx.ContextOptions.LazyLoadingEnabled = false;

如果'T'是一个DbContext它会这样做：

dbCtx.Configuration.ProxyCreationEnabled = false; dbCtx.Configuration.LazyLoadingEnabled = false;

You shouldn't have to download the source and modify it for such a simple thing. And now you won't have to.

We've pushed to GitHub a simple update to EFContextProvider. This change will appear in the next Breeze Runtime version (> 0.81.2).

Where EFContextProvider used to create the 'T' (your ObjectContext/DbContext) as follows:

_context = new T();

It now calls upon a virtual method, T CreateContext() instead, whose default implementation is:

protected virtual T CreateContext() { return new T(); }

Override and replace that in your EFContextProvider subclass and you will be able to make your context of type 'T' just the way you like it.

N.B.: The base EFContextProvider will still do a little post-creation configuration to make sure it behaves as we expect; we don't want the context doing any lazy loading or creating proxies.

So if 'T' is an ObjectContext, the provider will do this:

objCtx.ContextOptions.LazyLoadingEnabled = false;

and if 'T' is a DbContext it will do this:

dbCtx.Configuration.ProxyCreationEnabled = false; dbCtx.Configuration.LazyLoadingEnabled = false;