Question

I m 试图储存Linq要求的表述 OrderBy clauses in data structure, so, I can only go query = query. OrderBy(MySortExpression);

<代码>OrderBy,System.Linq.Expressions.Expression<Func<TSource,TKey>>作为参数。 <代码>TSource 是您分类的实体类型,但哪类是<代码>。 TKey 本应?

Answer 1

<编码> TKey是一种笼统的争论,指你所持有的表述类型。例如,如果你按长度分类,TSource将string和TKey将作为int。

string [] myStrings = new[] {"quick", "brown", "fox", "jumps"};
var ordered = myStrings.OrderBy(s => s.Length);

Answer 2

TKey is the type of the return type of the expression. For instance:

users.OrderBy(user => user.Name);

As Name is string, the type will be System.Linq.Expressions.Expression<Func<User,string>>

Answer 3

<代码>TKey不受特定类型的约束。通常,这是对不动产的预测,可以进行分类。

假定<代码>Person,附<代码>Birth%/code>,你将选择下列财产:

 persons.OrderBy(p => p.BirthYear);