MidpointRounding 列舉

定義

命名空間:

System

組件:

System.Runtime.dll

指定數學捨入方法應該用來四捨五入數位的策略。

C#

public enum MidpointRounding

繼承

Object

ValueType

Enum

MidpointRounding

欄位

名稱	值	Description
AwayFromZero	1	四捨五入為最接近數位的策略，而當數位介於兩個數字之間的一半時，會四捨五入到最接近零的數位。
ToEven	0	四捨五入為最接近數位的策略，而當數位在兩個數字之間半角時，就會四捨五入到最接近的偶數。
ToNegativeInfinity	3	向下導向捨入的策略，其結果最接近且不大於無限精確的結果。
ToPositiveInfinity	4	向上導向捨入的策略，其結果最接近且不小於無限精確的結果。
ToZero	2	將四捨五入為零的策略，其結果最接近且大小不大於無限精確結果。

範例

下列範例示範 Math.Round 方法與 MidpointRounding 列舉：

C#

decimal result;

// Round a positive value using different strategies.
// The precision of the result is 1 decimal place.

result = Math.Round(3.45m, 1, MidpointRounding.ToEven);
Console.WriteLine($"{result} = Math.Round({3.45m}, 1, MidpointRounding.ToEven)");
result = Math.Round(3.45m, 1, MidpointRounding.AwayFromZero);
Console.WriteLine($"{result} = Math.Round({3.45m}, 1, MidpointRounding.AwayFromZero)");
result = Math.Round(3.47m, 1, MidpointRounding.ToZero);
Console.WriteLine($"{result} = Math.Round({3.47m}, 1, MidpointRounding.ToZero)\n");

// Round a negative value using different strategies.
// The precision of the result is 1 decimal place.

result = Math.Round(-3.45m, 1, MidpointRounding.ToEven);
Console.WriteLine($"{result} = Math.Round({-3.45m}, 1, MidpointRounding.ToEven)");
result = Math.Round(-3.45m, 1, MidpointRounding.AwayFromZero);
Console.WriteLine($"{result} = Math.Round({-3.45m}, 1, MidpointRounding.AwayFromZero)");
result = Math.Round(-3.47m, 1, MidpointRounding.ToZero);
Console.WriteLine($"{result} = Math.Round({-3.47m}, 1, MidpointRounding.ToZero)\n");

/*
This code example produces the following results:

3.4 = Math.Round(3.45, 1, MidpointRounding.ToEven)
3.5 = Math.Round(3.45, 1, MidpointRounding.AwayFromZero)
3.4 = Math.Round(3.47, 1, MidpointRounding.ToZero)

-3.4 = Math.Round(-3.45, 1, MidpointRounding.ToEven)
-3.5 = Math.Round(-3.45, 1, MidpointRounding.AwayFromZero)
-3.4 = Math.Round(-3.47, 1, MidpointRounding.ToZero)
*/

備註

如需此 API 的詳細資訊，請參閱 MidpointRounding 的補充 API 備註。

適用於