MidpointRounding MidpointRounding MidpointRounding MidpointRounding Enum

Definición

Especifica cómo los métodos de redondeo matemáticos deben procesar un número que está comprendido entre dos números.Specifies how mathematical rounding methods should process a number that is midway between two numbers.

public enum class MidpointRounding
[System.Runtime.InteropServices.ComVisible(true)]
public enum MidpointRounding
type MidpointRounding = 
Public Enum MidpointRounding
Herencia
MidpointRoundingMidpointRoundingMidpointRoundingMidpointRounding
Atributos

Campos

AwayFromZero AwayFromZero AwayFromZero AwayFromZero 1

Cuando un número está comprendido entre otros dos, se redondea hacia el número más cercano y más alejado de cero.When a number is halfway between two others, it is rounded toward the nearest number that is away from zero.

ToEven ToEven ToEven ToEven 0

Cuando un número está comprendido entre dos otros, se redondea hacia el número par más cercano.When a number is halfway between two others, it is rounded toward the nearest even number.

ToNegativeInfinity ToNegativeInfinity ToNegativeInfinity ToNegativeInfinity 3
ToPositiveInfinity ToPositiveInfinity ToPositiveInfinity ToPositiveInfinity 4
ToZero ToZero ToZero ToZero 2

Ejemplos

En el ejemplo de código siguiente se muestra el Round método junto con el ToEven enumeración.The following code example demonstrates the Round method in conjunction with the ToEven enumeration.

// This example demonstrates the Math.Round() method in conjunction 
// with the MidpointRounding enumeration.
using namespace System;

void main()
{
    Decimal result = (Decimal) 0.0;
    Decimal posValue = (Decimal) 3.45;
    Decimal negValue = (Decimal) -3.45;

    // By default, round a positive and a negative value to the nearest
    // even number. The precision of the result is 1 decimal place.
    result = Math::Round(posValue, 1);
    Console::WriteLine("{0,4} = Math.Round({1,5}, 1)", result, posValue);
    result = Math::Round(negValue, 1);
    Console::WriteLine("{0,4} = Math.Round({1,5}, 1)", result, negValue);
    Console::WriteLine();

    // Round a positive value to the nearest even number, then to the
    // nearest number away from zero. The precision of the result is 1
    // decimal place.
    result = Math::Round(posValue, 1, MidpointRounding::ToEven);
    Console::WriteLine(
        "{0,4} = Math.Round({1,5}, 1, MidpointRounding.ToEven)",
        result, posValue);
    result = Math::Round(posValue, 1, MidpointRounding::AwayFromZero);
    Console::WriteLine(
        "{0,4} = Math.Round({1,5}, 1, MidpointRounding.AwayFromZero)",
        result, posValue);
    Console::WriteLine();

    // Round a negative value to the nearest even number, then to the
    // nearest number away from zero. The precision of the result is 1
    // decimal place.
    result = Math::Round(negValue, 1, MidpointRounding::ToEven);
    Console::WriteLine(
        "{0,4} = Math.Round({1,5}, 1, MidpointRounding.ToEven)",
        result, negValue);
    result = Math::Round(negValue, 1, MidpointRounding::AwayFromZero);
    Console::WriteLine(
        "{0,4} = Math.Round({1,5}, 1, MidpointRounding.AwayFromZero)",
        result, negValue);
    Console::WriteLine();
}

/*
This code example produces the following results:

3.4 = Math.Round( 3.45, 1)
-3.4 = Math.Round(-3.45, 1)

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

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

*/
decimal result = 0.0m;
decimal posValue =  3.45m;
decimal negValue = -3.45m;

// By default, round a positive and a negative value to the nearest even number. 
// The precision of the result is 1 decimal place.

result = Math.Round(posValue, 1);
Console.WriteLine("{0,4} = Math.Round({1,5}, 1)", result, posValue);
result = Math.Round(negValue, 1);
Console.WriteLine("{0,4} = Math.Round({1,5}, 1)", result, negValue);
Console.WriteLine();

// Round a positive value to the nearest even number, then to the nearest number away from zero. 
// The precision of the result is 1 decimal place.

result = Math.Round(posValue, 1, MidpointRounding.ToEven);
Console.WriteLine("{0,4} = Math.Round({1,5}, 1, MidpointRounding.ToEven)", result, posValue);
result = Math.Round(posValue, 1, MidpointRounding.AwayFromZero);
Console.WriteLine("{0,4} = Math.Round({1,5}, 1, MidpointRounding.AwayFromZero)", result, posValue);
Console.WriteLine();

// Round a negative value to the nearest even number, then to the nearest number away from zero. 
// The precision of the result is 1 decimal place.

result = Math.Round(negValue, 1, MidpointRounding.ToEven);
Console.WriteLine("{0,4} = Math.Round({1,5}, 1, MidpointRounding.ToEven)", result, negValue);
result = Math.Round(negValue, 1, MidpointRounding.AwayFromZero);
Console.WriteLine("{0,4} = Math.Round({1,5}, 1, MidpointRounding.AwayFromZero)", result, negValue);
Console.WriteLine();
/*
This code example produces the following results:

3.4 = Math.Round( 3.45, 1)
-3.4 = Math.Round(-3.45, 1)

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

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

*/
' This example demonstrates the Math.Round() method in conjunction 
' with the MidpointRounding enumeration.
Imports System

Class Sample
    Public Shared Sub Main() 
        Dim result As Decimal = 0D
        Dim posValue As Decimal = 3.45D
        Dim negValue As Decimal = -3.45D
        
        ' By default, round a positive and a negative value to the nearest even number. 
        ' The precision of the result is 1 decimal place.
        result = Math.Round(posValue, 1)
        Console.WriteLine("{0,4} = Math.Round({1,5}, 1)", result, posValue)
        result = Math.Round(negValue, 1)
        Console.WriteLine("{0,4} = Math.Round({1,5}, 1)", result, negValue)
        Console.WriteLine()
        
        ' Round a positive value to the nearest even number, then to the nearest number 
        ' away from zero. The precision of the result is 1 decimal place.
        result = Math.Round(posValue, 1, MidpointRounding.ToEven)
        Console.WriteLine("{0,4} = Math.Round({1,5}, 1, MidpointRounding.ToEven)", _
                           result, posValue)
        result = Math.Round(posValue, 1, MidpointRounding.AwayFromZero)
        Console.WriteLine("{0,4} = Math.Round({1,5}, 1, MidpointRounding.AwayFromZero)", _
                           result, posValue)
        Console.WriteLine()
        
        ' Round a negative value to the nearest even number, then to the nearest number 
        ' away from zero. The precision of the result is 1 decimal place.
        result = Math.Round(negValue, 1, MidpointRounding.ToEven)
        Console.WriteLine("{0,4} = Math.Round({1,5}, 1, MidpointRounding.ToEven)", _
                            result, negValue)
        result = Math.Round(negValue, 1, MidpointRounding.AwayFromZero)
        Console.WriteLine("{0,4} = Math.Round({1,5}, 1, MidpointRounding.AwayFromZero)", _
                           result, negValue)
        Console.WriteLine()
    
    End Sub 'Main
End Class 'Sample
'
'This code example produces the following results:
'
' 3.4 = Math.Round( 3.45, 1)
'-3.4 = Math.Round(-3.45, 1)
'
' 3.4 = Math.Round( 3.45, 1, MidpointRounding.ToEven)
' 3.5 = Math.Round( 3.45, 1, MidpointRounding.AwayFromZero)
'
'-3.4 = Math.Round(-3.45, 1, MidpointRounding.ToEven)
'-3.5 = Math.Round(-3.45, 1, MidpointRounding.AwayFromZero)
'

Comentarios

Use MidpointRounding con las sobrecargas adecuadas de Math.Round para proporcionar mayor control sobre el proceso de redondeo.Use MidpointRounding with appropriate overloads of Math.Round to provide more control of the rounding process.

Una operación de redondeo toma un número original con una precisión especificada o implícita; examina el dígito siguiente, que se encuentra en esa precisión más uno; y devuelve el número más cercano con la misma precisión que el número original.A rounding operation takes an original number with an implicit or specified precision; examines the next digit, which is at that precision plus one; and returns the nearest number with the same precision as the original number. Para los números positivos, si el dígito siguiente está comprendido entre 0 y 4, es el número más cercano a infinito negativo.For positive numbers, if the next digit is from 0 through 4, the nearest number is toward negative infinity. Si el dígito siguiente es de 6 a 9, es el número más próximo a infinito positivo.If the next digit is from 6 through 9, the nearest number is toward positive infinity. Para los números negativos, si el dígito siguiente está comprendido entre 0 y 4, es el número más cercano a infinito positivo.For negative numbers, if the next digit is from 0 through 4, the nearest number is toward positive infinity. Si el dígito siguiente es de 6 a 9, es el número más próximo a infinito negativo.If the next digit is from 6 through 9, the nearest number is toward negative infinity.

En los casos anteriores, el MidpointRounding enumeración no afecta al resultado de la operación de redondeo.In the previous cases, the MidpointRounding enumeration does not affect the result of the rounding operation. Sin embargo, si el dígito siguiente es 5, que es el punto medio entre dos resultados posibles y todos los dígitos restantes son cero o no hay ningún dígito restante, el número más cercano es ambiguo.However, if the next digit is 5, which is the midpoint between two possible results, and all remaining digits are zero or there are no remaining digits, the nearest number is ambiguous. En este caso, el MidpointRounding enumeración le permite especificar si la operación de redondeo devuelve el número más cercano lejos de cero o el número par más cercano.In this case, the MidpointRounding enumeration enables you to specify whether the rounding operation returns the nearest number away from zero or the nearest even number.

En la tabla siguiente se muestra el resultado de redondear algunos números negativos y positivos junto con los valores de MidpointRounding.The following table demonstrates the results of rounding some negative and positive numbers in conjunction with the values of MidpointRounding. La precisión usada para redondear los números es cero, lo que significa que el número después del separador decimal afecta a la operación de redondeo.The precision used to round the numbers is zero, which means the number after the decimal point affects the rounding operation. Por ejemplo, para el número -2,5, el dígito después del separador decimal es 5.For example, for the number -2.5, the digit after the decimal point is 5. Dado que ese dígito es el punto medio, puede usar un MidpointRounding valor para determinar el resultado de redondear.Because that digit is the midpoint, you can use a MidpointRounding value to determine the result of rounding. Si se especifica AwayFromZero, -3 se devuelve porque es el número más cercano, alejándose de cero con una precisión de cero.If AwayFromZero is specified, -3 is returned because it is the nearest number away from zero with a precision of zero. Si se especifica ToEven, se devuelve -2 porque es el número par más cercano con una precisión de cero.If ToEven is specified, -2 is returned because it is the nearest even number with a precision of zero.

Número originalOriginal number AwayFromZeroAwayFromZero ToEvenToEven
3.53.5 44 44
2.82.8 33 33
2.52.5 33 22
2.12.1 22 22
-2.1-2.1 -2-2 -2-2
-2.5-2.5 -3-3 -2-2
-2.8-2.8 -3-3 -3-3
-3.5-3.5 -4-4 -4-4

Se aplica a