Nullable.GetUnderlyingType(Type) 메서드

정의

네임스페이스:

System

어셈블리:

System.Runtime.dll

Source:

Nullable.cs

지정된 nullable 형식의 내부 형식 인수를 반환합니다.

public:
 static Type ^ GetUnderlyingType(Type ^ nullableType);

public static Type? GetUnderlyingType (Type nullableType);

static member GetUnderlyingType : Type -> Type

Public Shared Function GetUnderlyingType (nullableType As Type) As Type

매개 변수

nullableType

Type

폐쇄형 제네릭 nullable 형식을 설명하는 Type 개체입니다.

반환

Type

nullableType 매개 변수가 폐쇄형 제네릭 nullable 형식이면 nullableType 매개 변수의 형식 인수이고, 그렇지 않으면 null입니다.

예외

ArgumentNullException

nullableType이(가) null인 경우

예제

다음 코드 예제에서는 반환 값이 형식 Nullable<T> 인 메서드를 정의합니다 Int32. 이 코드 예제에서는 메서드를 GetUnderlyingType 사용하여 반환 값의 형식 인수를 표시합니다.

// This code example demonstrates the
// Nullable.GetUnderlyingType() method.

using System;
using System.Reflection;

class Sample
{
// Declare a type named Example.
// The MyMethod member of Example returns a Nullable of Int32.

    public class Example
    {
        public int? MyMethod()
        {
        return 0;
        }
    }

/*
   Use reflection to obtain a Type object for the Example type.
   Use the Type object to obtain a MethodInfo object for the MyMethod method.
   Use the MethodInfo object to obtain the type of the return value of
     MyMethod, which is Nullable of Int32.
   Use the GetUnderlyingType method to obtain the type argument of the
     return value type, which is Int32.
*/
    public static void Main()
    {
        Type t = typeof(Example);
        MethodInfo mi = t.GetMethod("MyMethod");
        Type retval = mi.ReturnType;
        Console.WriteLine("Return value type ... {0}", retval);
        Type answer = Nullable.GetUnderlyingType(retval);
        Console.WriteLine("Underlying type ..... {0}", answer);
    }
}
/*
This code example produces the following results:

Return value type ... System.Nullable`1[System.Int32]
Underlying type ..... System.Int32

*/

// This code example demonstrates the
// Nullable.GetUnderlyingType() method.
open System

// Declare a type named Example.
// The MyMethod member of Example returns a Nullable of Int32.

type Example() =
    member _.MyMethod() =
        Nullable 0

(*
   Use reflection to obtain a Type object for the Example type.
   Use the Type object to obtain a MethodInfo object for the MyMethod method.
   Use the MethodInfo object to obtain the type of the return value of
     MyMethod, which is Nullable of Int32.
   Use the GetUnderlyingType method to obtain the type argument of the
     return value type, which is Int32.
*)
let t = typeof<Example>
let mi = t.GetMethod "MyMethod"
let retval = mi.ReturnType
printfn $"Return value type ... {retval}"
let answer = Nullable.GetUnderlyingType retval
printfn $"Underlying type ..... {answer}"

// This code example produces the following results:
//     Return value type ... System.Nullable`1[System.Int32]
//     Underlying type ..... System.Int32

' This code example demonstrates the 
' Nullable.GetUnderlyingType() method.

Imports System.Reflection

Class Sample
    ' Declare a type named Example. 
    ' The MyMethod member of Example returns a Nullable of Int32.
    
    Public Class Example
        Public Function MyMethod() As Nullable(Of Integer)
            Return 0
        End Function
    End Class
    
' 
'   Use reflection to obtain a Type object for the Example type.
'   Use the Type object to obtain a MethodInfo object for the MyMethod method.
'   Use the MethodInfo object to obtain the type of the return value of 
'     MyMethod, which is Nullable of Int32.
'   Use the GetUnderlyingType method to obtain the type argument of the 
'     return value type, which is Int32.
'
    Public Shared Sub Main() 
        Dim t As Type = GetType(Example)
        Dim mi As MethodInfo = t.GetMethod("MyMethod")
        Dim retval As Type = mi.ReturnType
        Console.WriteLine("Return value type ... {0}", retval)
        Dim answer As Type = Nullable.GetUnderlyingType(retval)
        Console.WriteLine("Underlying type ..... {0}", answer)
    
    End Sub
End Class
'
'This code example produces the following results:
'
'Return value type ... System.Nullable`1[System.Int32]
'Underlying type ..... System.Int32
'

설명

제네릭 형식 정의는 형식 매개 변수 목록을 포함하는 와 같은 Nullable<T>형식 선언이며 형식 매개 변수 목록은 하나 이상의 형식 매개 변수를 선언합니다. 닫힌 제네릭 형식은 형식 매개 변수에 대해 특정 형식이 지정된 형식 선언입니다.

예를 들어 매개 변수가 nullableType C#의 Nullable<Int32> 형식(Nullable(Of Int32) Visual Basic의 경우)인 경우 반환 값은 형식 Int32 (즉, 닫힌 제네릭 형식의 형식 인수)입니다.