问题:

I have a Linq query that I want to call from multiple places:

var myData = from a in db.MyTable
             where a.MyValue == "A"
             select new  {
                            a.Key,
                            a.MyValue
                          };

How can I create a method, put this code in it, and then call it?

public  ???  GetSomeData()
{
   // my Linq query
}

回答1:

IQueryable and IEnumerable both work. But you want to use a type specific version, IQueryable<T> or IEnumerable <T>.

So you'll want to create a type to keep the data.

var myData = from a in db.MyTable
             where a.MyValue == "A"
             select new MyType
             {
                 Key = a.Key,
                 Value = a.MyValue
             };

回答2:

IQueryable

So your method declaration would look like

public IQueryable GetSomeData()

回答3:

A generic method should give you intellisense:

public class MyType {Key{get;set;} Value{get;set}}

public IQueryable<T> GetSomeData<T>() where T : MyType, new() 
 { return from a in db.MyTable
          where a.MyValue == "A" 
          select new T {Key=a.Key,Value=a.MyValue};
 }