C# Decimal.Round()方法用法及代碼示例

Decimal.Round方法用於將值舍入到最接近的整數或指定數量的小數位數。此方法的重載列表中有4種方法，如下所示：

Round(Decimal) 方法
Round(Decimal，Int32)方法
Round(Decimal, MidpointRounding) 方法
Round(Decimal，Int32，MidpointRounding)方法

在這裏，我們將討論前兩種方法。

Decimal.Round(Decimal) Method

此方法用於將十進製值舍入到最接近的整數。

用法： public static decimal Round (decimal d);

Here, it takes a decimal number to round.

返回值：此方法返回最接近d參數的整數。如果d在兩個整數之間，其中一個是偶數，另一個是奇數，則返回偶數。

異常：如果結果超出Decimal值的範圍，則此方法將引發OverflowException。

以下示例程序旨在說明Decimal.Round(Decimal)方法的用法：

範例1：

// C# program to demonstrate the 
// Decimal.Round(Decimal) Method 
using System; 
  
class GFG { 
  
    // Main Method 
    public static void Main() 
    { 
        try { 
  
            // Declaring and initializing value 
            decimal value = 184467440737095.51615M; 
  
            // getting rounded decimal 
            // using Round() method 
            decimal round = Decimal.Round(value); 
  
            // Display the value 
            Console.WriteLine("Rounded value is {0}", round); 
        } 
  
        catch (OverflowException e)  
        { 
            Console.WriteLine("Value must not be out of bound"); 
            Console.Write("Exception Thrown:"); 
            Console.Write("{0}", e.GetType(), e.Message); 
        } 
    } 
}

輸出：

Rounded value is 184467440737096

範例2：對於OverflowException

// C# program to demonstrate the 
// Decimal.Round(Decimal) Method 
using System; 
  
class GFG { 
  
    // Main Method 
    public static void Main() 
    { 
  
        try 
        { 
  
            // Declaring and initializing value 
            decimal value = 79228162514264337593543950335.5M; 
  
            // getting rounded decimal 
            // using Round() method 
            decimal round = Decimal.Round(value); 
  
            // Display the value 
            Console.WriteLine("Rounded value is {0}", round); 
        } 
  
        catch (OverflowException e)  
        { 
            Console.WriteLine("Value must not be out of bound"); 
            Console.Write("Exception Thrown:"); 
            Console.Write("{0}", e.GetType(), e.Message); 
        } 
    } 
}

Compile-Time錯誤：

prog.cs(15,51):error CS0594:Floating-point constant is outside the range of type `decimal’

Round(Decimal, Int32) Method

此方法用於將十進製值舍入到指定的小數位數。

用法： public static decimal Round (decimal d, int decimals);

參數：
d:它是一個十進製數，將被四舍五入。
decimals:從0到28的值，指定要舍入到的小數位數。

返回值：此方法返回等於d的十進製數，四舍五入為小數位的小數位數。

異常：如果小數位數不是0到28之間的值，則此方法將引發ArgumentOutOfRangeException。

以下示例程序旨在說明Decimal.Round(Decimal，Int32)方法的用法：

範例1：

// C# program to demonstrate the 
// Decimal.Round(Decimal) Method 
using System; 
  
class GFG { 
  
    // Main Method 
    public static void Main() 
    { 
        try { 
  
            // Declaring and initializing value 
            decimal value = 7922816251426433759354.39503305M; 
  
            // getting rounded decimal 
            // using Round() method 
            decimal round = Decimal.Round(value, 4); 
  
            // Display the value 
            Console.WriteLine("Rounded value is {0}", round); 
        } 
  
        catch (ArgumentOutOfRangeException e)  
        { 
            Console.WriteLine("decimal place is not within bound"); 
            Console.Write("Exception Thrown:"); 
            Console.Write("{0}", e.GetType(), e.Message); 
        } 
    } 
}

輸出：

Rounded value is 7922816251426433759354.3950

範例2：對於ArgumentOutOfRangeException

// C# program to demonstrate the 
// Decimal.Round(Decimal) Method 
using System; 
  
class GFG { 
  
    // Main Method 
    public static void Main() 
    { 
        try 
        { 
  
            // Declaring and initializing value 
            decimal value = 7922816251426433759354.39503305M; 
  
            // getting rounded decimal 
            // using Round() method 
            decimal round = Decimal.Round(value, 29); 
  
            // Display the value 
            Console.WriteLine("Rounded value is {0}", round); 
        } 
  
        catch (ArgumentOutOfRangeException e)  
        { 
            Console.WriteLine("Decimal place is not within bound"); 
            Console.Write("Exception Thrown:"); 
            Console.Write("{0}", e.GetType(), e.Message); 
        } 
    } 
}

輸出：

Decimal place is not within bound
Exception Thrown:System.ArgumentOutOfRangeException

參考：

https://docs.microsoft.com/en-us/dotnet/api/system.decimal.round?view=netframework-4.7.2

相關用法

注：本文由純淨天空篩選整理自RohitPrasad3大神的英文原創作品 Decimal.Round() Method in C# | Set – 1。非經特殊聲明，原始代碼版權歸原作者所有，本譯文未經允許或授權，請勿轉載或複製。