如何将Func与返回IOrderedQueryable的IQueryable一起使用 [英] How to use Func with IQueryable that returns IOrderedQueryable

问题描述

我正在做一些关于EF的研究，并且遇到了一个可以接受的功能

I'm doing some research about EF and came across a function that accepts

Func<IQueryable<Student>, IOrderedQueryable<Student>> 

，只是想知道如何调用接受此类参数的函数?

and just wondering how to call that function that accepts that kind of parameter?

推荐答案

想象函数就是这样，您在Student类中有一个属性ID.

imagine function is something like that, and you've got a property Id in Student class.

public static class Helper {
    public static void Test(Func<IQueryable<Student>, IOrderedQueryable<Student>> param)
        {
            var test = 0;
        }
}

那么您可以通过这种方式使用它

then you could use it this way

var student = new List<Student>().AsQueryable();//non sense, just for example
Helper.Test(m => student.OrderBy(x => x.Id));

m => student.OrderBy(x => x.Id)是一个

Func<IQueryable<Student>, IOrderedQueryable<Student>>

(IQueryable<student>作为参数，返回IOrderedQueryable<Student>)

或者只是

Helper.Test(m => m.OrderBy(x => x.Id));

实际上，没有真实"功能并没有多大意义...

In fact this doesn't make much sense without a "real" function...

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