C# 更好的定义上下文对象的方法

我希望每次都使用实体框架上下文对象。 在asp.net中定义的更好方法是什么

例：

---

我希望在任何地方都使用此上下文，而不必使用

重复使用

，虽然您可以这样做，但microsoft建议您以不同的方式使用上下文，请查看：

另外，请看一下这个相关的线程：
如果您只是想使用一些语法来避免使用
而每次都创建一个新的上下文，那么您可以编写一些扩展方法来帮助您编写如下代码：

// Execute is the extension method which takes the code 
// in the using block as a delegate
SomeEntities.Execute(context => 
    context.SomeTable.Where(item => item.Ammount > 100));

如果你想要的话，我可以和你分享代码。如果您想始终使用单个上下文，请参考CloudyMarble的答案。
相关：请定义everywhere？班级里到处都是？在你的整个项目中？
...
The lifetime of the ObjectContext begins when the instance is created and ends when the instance is either disposed or garbage-collected. Use using if you want all the resources that the context controls to be disposed at the end of the block. When you use using, the compiler creates a try/finally block and calls dispose in the finally block. Here are some general guidelines when deciding on the lifetime of the object context:

1. When working with long-running object context consider the following:
 - As you load more objects and their references into memory, the object
   context may grow quickly in memory consumption. This may cause

   performance issues.
 - Remember to dispose of the context when it is no longer required.
 - If an exception caused the object context to be in an unrecoverable
   state, the whole application may terminate.
 - The chances of running into concurrency-related issues increase as
   the gap between the time when the data is queried and updated grows.

2. When working with Web applications, **use an object context instance per request**... 

3. When working with Windows Presentation Foundation (WPF) or Windows Forms, use an object context instance per form. This lets you use change tracking functionality that object context provides. 
...

// Execute is the extension method which takes the code 
// in the using block as a delegate
SomeEntities.Execute(context => 
    context.SomeTable.Where(item => item.Ammount > 100));