C# EF添加ADO.NET实体数据模型时，产生.Desiger.cs文件为空

// T4 code generation is enabled for model 'D:\DKX4003\work\VWFC_CCS\SrcCCG-branch\CCGSPBOCOne-FCA\CUP\VWFC.IT.CUP.DAL\CupCreditQueryModel.edmx'.
// To enable legacy code generation, change the value of the 'Code Generation Strategy' designer
// property to 'Legacy ObjectContext'. This property is available in the Properties Window when the model
// is open in the designer.

// If no context and entity classes have been generated, it may be because you created an empty model but
// have not yet chosen which version of Entity Framework to use. To generate a context class and entity
// classes for your model, open the model in the designer, right-click on the designer surface, and
// select 'Update Model from Database...', 'Generate Database from Model...', or 'Add Code Generation
// Item...'.

原因：添加实体时“代码生成策略”  的值是为 “T4”

解决办法：在”关系图“空白处，即.edmx文件里的空白处右键选属性，找到“代码生成策略”，将值“T4”改为“Legacy ObjectContext”，保存后.Desiger.cs文件中就生成代码了。

同时删除多余的.Context.tt和.tt文件。