我不知道为什么它的工作，但它现在。我从代码中删除了连接属性，我创建了一个app.config文件，并通过此博客更正了创建数据库的错误 http://brice-lambson.blogspot.fr/2012/05/using-entity-framework-code-first-with.html ，现在它的作品

I dunno why it works but it does now. I removed the connection properties from the code and I've created an app.config file and correct a bug at the database creation with this blog http://brice-lambson.blogspot.fr/2012/05/using-entity-framework-code-first-with.html and now it works