C＃| Type.GetEnumUnderlyingType()方法

Type.GetEnumUnderlyingType()方法用于返回当前枚举类型的基础类型。

句法：

public virtual Type GetEnumUnderlyingType ();

返回值：该方法返回当前枚举的基础类型。

异常：如果当前类型不是枚举或枚举类型无效(由于包含多个实例字段)，则此方法将返回ArgumentException。

下面的程序说明了上述方法的用法：

范例1：

// C# program to demonstrate the
// Type.GetEnumUnderlyingType() Method
using System;
using System.Globalization;
using System.Reflection;
  
class GFG {
  
    // Defining enum ABC
    enum ABC { A,
               B,
               C,
               D,
               E,
               F }
  
    // Main Method
    public static void Main()
    {
  
        // try-catch block to
        // handle exceptions
        try {
  
            // Creating and initializing object
            // of ABC with instace of enum ABC
            ABC a = ABC.A;
  
            // Declaring and initializing
            // object of Type
            Type type = a.GetType();
  
            // Getting underlying type of current enumeration
            // By using GetEnumUnderlyingType() method
            Type obj = type.GetEnumUnderlyingType();
  
            // Display underlying type
            Console.Write("Underlying type is : {0} ", obj);
        }
  
        // ArgumentException here
        catch (ArgumentException e) 
        {
            Console.Write("The current type is not an enumeration.");
            Console.Write("Exception Thrown: ");
            Console.Write("{0}", e.GetType(), e.Message);
        }
    }
}

输出：

Underlying type is : System.Int32

示例2：对于ArgumentException

// C# program to demonstrate the
// Type.GetEnumUnderlyingType() Method
using System;
using System.Globalization;
using System.Reflection;
  
class GFG {
  
    // Defining enum ABC
    enum ABC { A,
               B,
               C,
               D,
               E,
               F }
  
    // Main Method
    public static void Main()
    {
  
        // try-catch block to
        // handle exceptions
        try {
  
            // Declaring and initializing
            // object of Type
            Type type = typeof(int);
  
            // Getting underlying type of current enumeration
            // By using GetEnumUnderlyingType() method
            Type obj = type.GetEnumUnderlyingType();
  
            // Display underlying type
            Console.Write("underlying type is : {0} ", obj);
        }
  
        // catch ArgumentException here
        catch (ArgumentException e) 
        {
            Console.WriteLine("The current type is not an enumeration.");
            Console.Write("Exception Thrown: ");
            Console.Write("{0}", e.GetType(), e.Message);
        }
    }
}

输出：

The current type is not an enumeration.
Exception Thrown: System.ArgumentException

参考：

• https://docs.microsoft.com/zh-cn/dotnet/api/system.type.getenumunderlyingtype?view=netframework-4.8