到位的IComparer参数的使用lambda表达式 [英] Using lambda expression in place of IComparer argument

问题描述

是否有可能与C＃传递lambda表达式作为一个方法调用的IComparer的说法？

Is it possible with C# to pass a lambda expression as an IComparer argument in a method call?

如像

var x = someIEnumerable.OrderBy(aClass e => e.someProperty, 
(aClass x, aClass y) => { return x.someProperty > y.SomeProperty ?  1 : x.someProperty < y.SomeProperty ?  -1 : 0;  } 
 );

我不能完全得到这个编译所以我猜没有，但似乎这样的lambda表达式和匿名委托，我觉得我必须做一些愚蠢的错误之间明显的协同效应。

I can't quite get this to compile so I'm guessing not, but it seems such an obvious synergy between lambdas and anonymous delegates that I feel I must be doing something foolishly wrong.

TIA

推荐答案

由于叶普指出，如果你在.NET 4.5中，可以使用静态方法的Comparer< T> .Create

As Jeppe points out, if you're on .NET 4.5, you can use the static method Comparer<T>.Create.

，这是应该是等价的实现：

If not, this is an implementation that should be equivalent:

public class FunctionalComparer<T> : IComparer<T>
{
    private Func<T, T, int> comparer;
    public FunctionalComparer(Func<T, T, int> comparer)
    {
        this.comparer = comparer;
    }
    public static IComparer<T> Create(Func<T, T, int> comparer)
    {
        return new FunctionalComparer<T>(comparer);
    }
    public int Compare(T x, T y)
    {
        return comparer(x, y);
    }
}

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