由网友(做人留一线日后好相见)分享简介：据这里的博客文章数据注释中的实体框架应该有一个名为键栏中，它允许您标记一个实体的主键的属性。不过，我不能在.NET 3.5中或.Net 4.0查找此。According to the blog post here Data Annotations in the Entity Framework there shoul...

据这里的博客文章数据注释中的实体框架应该有一个名为键栏中，它允许您标记一个实体的主键的属性。不过，我不能在.NET 3.5中或.Net 4.0查找此。

According to the blog post here Data Annotations in the Entity Framework there should be an attribute for a column called "Key" which allows you to mark the primary key of an entity. However I cannot locate this in .Net 3.5 or .Net 4.0.

我有什么遗漏？我已经包括了参考EntityFramework.dll，我已经检查了所有的属性在 System.ComponentModel.DataAnnotations 但我不能找到它。

What have I missed? I've included the reference to EntityFramework.dll and I've checked all the attributes under System.ComponentModel.DataAnnotations but I cannot locate it.

我已经把我的项目到.NET 4.0全（不是客户端配置文件）。

I have set my project to .Net 4.0 full (not client profile).

任何想法？

推荐答案

的KeyAttribute .NET是唯一的4，它位于 System.ComponentModel.DataAnnotations 组装所以一定要确保你已经提到了。

The KeyAttribute is .NET 4 only and it is located in the System.ComponentModel.DataAnnotations assembly so make sure you have referenced it.