通过一些扩展方法的滥用，我们可以得到以下“优雅”的解决方案:

using System;

namespace Elegant {
    public class Range {
        public int Lower { get; set; }
        public int Upper { get; set; }
    }

    public static class Ext {
        public static Range To(this int lower, int upper) {
            return new Range { Lower = lower, Upper = upper };
        }

        public static bool In(this int n, Range r) {
            return n >= r.Lower && n <= r.Upper;
        }
    }

    class Program {
        static void Main() {
            int x = 55;
            if (x.In(1.To(100)))
                Console.WriteLine("it's in range! elegantly!");
        }
    }
}

你的意思是?

if(number >= 1 && number <= 100)

or

bool TestRange (int numberToCheck, int bottom, int top)
{
  return (numberToCheck >= bottom && numberToCheck <= top);
}

使用内置的Range结构体(c# 8+)，我们可以创建一个扩展方法来检查索引是否在原始范围内。

public static bool IsInRangeOf(this Range range, Index index)
{
   return index.Value >= range.Start.Value && index.Value < range.End.Value;
}

由于Index覆盖隐式操作符，因此可以传递int型而不是Index结构体。

var range = new Range(1, 10);
var isInRange = range.IsInRangeOf(1); // true, 1..10 is inclusive min range index(1)
var isInRange = range.IsInRangeOf(10); // false, 1..10 exclusive on max range index (10).
var isInRange = range.IsInRangeOf(100); // false

如果您关心@Daap对已接受答案的注释，并且只能传递一次值，则可以尝试以下方法之一

bool TestRangeDistance (int numberToCheck, int bottom, int distance)
{
  return (numberToCheck >= bottom && numberToCheck <= bottom+distance);
}

//var t = TestRangeDistance(10, somelist.Count()-5, 10);

or

bool TestRangeMargin (int numberToCheck, int target, int margin)
{
  return (numberToCheck >= target-margin && numberToCheck <= target+margin);
}

//var t = TestRangeMargin(10, somelist.Count(), 5);

你在寻找[1..100]?这只是帕斯卡。

新花样的老最爱:

public bool IsWithinRange(int number, int topOfRange, int bottomOfRange, bool includeBoundaries) {
    if (includeBoundaries)
        return number <= topOfRange && number >= bottomOfRange;
    return number < topOfRange && number > bottomOfRange;
}