c# - Math.Round 返回奇数向上舍入但偶数向下舍入

Question

我正在尝试使用数学回合找到一个 float 我发现了以下内容

0.5 --> 0
1.5 --> 2
2.5 --> 2
3.5 --> 4

等等。我相信这是由于浮点错误造成的，但不太确定是如何造成的。我怎样才能解决这个问题，以便偶数正确舍入？

Answer 1

来自 documentation ;

The integer nearest a. If the fractional component of a is halfway between two integers, one of which is even and the other odd, then the even number is returned. Note that this method returns a Double instead of an integral type.

Math.Round 方法有一些 overloads这需要 MidpointRounding作为一个参数，您可以指定舍入值，如果它在两个数字之间。

AwayFromZero 

When a number is halfway between two others, it is rounded toward the nearest number that is away from zero.

ToEven

When a number is halfway between two others, it is rounded toward the nearest even number.