问题
I have been googling this non stop for 2 days now and can't find a single complete, ready to use, fully implemented t4 template that generates DataAnnotations. Do they even exist?
I generate POCOs with the standard t4 templates. The actual database table has metadata that describes some of the validation rules, eg not null, nvarchar(25), etc.
So all I want is a t4 template that can take my table and generate a POCO with DataAnnotations, eg
public class Person
{
[Required]
[StringLength(255)]
public FirstName {get;set}
}
It is a basic and fundamental requirement, surely I can not be the first person in the entire world to have this requirement? I don't want to re-invent the wheel here. Yet I haven't found it after searching high and low for days.
This must be possible (and hopefully must be available somewhere to just download) - it would be criminally wrong to have to manually type in these annotations when the metadata for them already exists in the database.
回答1:
Here is what you want!
T4 Metadata and Data Annotations Template
This T4 template handles generating metadata classes from an Entity Framework 4 model and decorates properties with data annotation attributes such as [Required] and [StringLength]. The [DataType] attribute is also applied when appropriate. It'll also generate ErrorMessage values based upon property names for required fields.
来源：https://stackoverflow.com/questions/2748619/where-are-the-entity-framework-t4-templates-for-data-annotations