Type.DeclaringMethod Properti

Definisi

Ruang nama:

System

Rakitan:

netstandard.dll, System.Runtime.dll

Sumber:

Type.cs

MethodBase Mendapatkan yang mewakili metode deklarasikan, jika saat ini Type mewakili parameter jenis metode generik.

public:
 virtual property System::Reflection::MethodBase ^ DeclaringMethod { System::Reflection::MethodBase ^ get(); };

public virtual System.Reflection.MethodBase? DeclaringMethod { get; }

member this.DeclaringMethod : System.Reflection.MethodBase

Public Overridable ReadOnly Property DeclaringMethod As MethodBase

Nilai Properti

MethodBase

Jika saat ini Type mewakili parameter jenis metode generik, MethodBase yang mewakili metode deklarasikan; jika tidak, null.

Contoh

Contoh kode berikut mendefinisikan kelas yang memiliki metode generik, menetapkan argumen jenis ke metode , dan memanggil metode generik yang dibuat yang dihasilkan. Ini juga menampilkan informasi tentang definisi metode generik dan metode yang dibangun. Saat menampilkan informasi tentang parameter jenis definisi metode generik, dalam DisplayGenericMethodInfo metode , kode contoh menunjukkan nilai DeclaringMethod properti untuk parameter jenis generik metode.

using System;
using System.Reflection;

// Define a class with a generic method.
public class Example
{
    public static void Generic<T>(T toDisplay)
    {
        Console.WriteLine("\r\nHere it is: {0}", toDisplay);
    }
}

public class Test
{
    public static void Main()
    {
        Console.WriteLine("\r\n--- Examine a generic method.");

        // Create a Type object representing class Example, and
        // get a MethodInfo representing the generic method.
        //
        Type ex = typeof(Example);
        MethodInfo mi = ex.GetMethod("Generic");

        DisplayGenericMethodInfo(mi);

        // Assign the int type to the type parameter of the Example
        // method.
        //
        MethodInfo miConstructed = mi.MakeGenericMethod(typeof(int));

        DisplayGenericMethodInfo(miConstructed);

        // Invoke the method.
        object[] args = {42};
        miConstructed.Invoke(null, args);

        // Invoke the method normally.
        Example.Generic<int>(42);

        // Get the generic type definition from the closed method,
        // and show it's the same as the original definition.
        //
        MethodInfo miDef = miConstructed.GetGenericMethodDefinition();
        Console.WriteLine("\r\nThe definition is the same: {0}",
            miDef == mi);
    }

    private static void DisplayGenericMethodInfo(MethodInfo mi)
    {
        Console.WriteLine("\r\n{0}", mi);

        Console.WriteLine("\tIs this a generic method definition? {0}",
            mi.IsGenericMethodDefinition);

        Console.WriteLine("\tIs it a generic method? {0}",
            mi.IsGenericMethod);

        Console.WriteLine("\tDoes it have unassigned generic parameters? {0}",
            mi.ContainsGenericParameters);

        // If this is a generic method, display its type arguments.
        //
        if (mi.IsGenericMethod)
        {
            Type[] typeArguments = mi.GetGenericArguments();

            Console.WriteLine("\tList type arguments ({0}):",
                typeArguments.Length);

            foreach (Type tParam in typeArguments)
            {
                // IsGenericParameter is true only for generic type
                // parameters.
                //
                if (tParam.IsGenericParameter)
                {
                    Console.WriteLine("\t\t{0}  parameter position {1}" +
                        "\n\t\t   declaring method: {2}",
                        tParam,
                        tParam.GenericParameterPosition,
                        tParam.DeclaringMethod);
                }
                else
                {
                    Console.WriteLine("\t\t{0}", tParam);
                }
            }
        }
    }
}

/* This example produces the following output:

--- Examine a generic method.

Void Generic[T](T)
        Is this a generic method definition? True
        Is it a generic method? True
        Does it have unassigned generic parameters? True
        List type arguments (1):
                T  parameter position 0
                   declaring method: Void Generic[T](T)

Void Generic[Int32](Int32)
        Is this a generic method definition? False
        Is it a generic method? True
        Does it have unassigned generic parameters? False
        List type arguments (1):
                System.Int32

Here it is: 42

Here it is: 42

The definition is the same: True

 */

open System.Reflection

// Define a class with a generic method.
type Example =
    static member Generic<'T>(toDisplay: 'T) =
        printfn $"\r\nHere it is: {toDisplay}"

let displayGenericMethodInfo (mi: MethodInfo) =
    printfn $"\n{mi}"

    printfn $"\tIs this a generic method definition? {mi.IsGenericMethodDefinition}"

    printfn $"\tIs it a generic method? {mi.IsGenericMethod}"

    printfn $"\tDoes it have unassigned generic parameters? {mi.ContainsGenericParameters}"

    // If this is a generic method, display its type arguments.
    //
    if mi.IsGenericMethod then
        let typeArguments = mi.GetGenericArguments()

        printfn $"\tList type arguments ({typeArguments.Length}):"

        for tParam in typeArguments do
            // IsGenericParameter is true only for generic type
            // parameters.
            if tParam.IsGenericParameter then
                printfn $"\t\t{tParam}  parameter position {tParam.GenericParameterPosition}\n\t\t   declaring method: {tParam.DeclaringMethod}"
            else
                printfn $"\t\t{tParam}"

printfn "\r\n--- Examine a generic method."

// Create a Type object representing class Example, and
// get a MethodInfo representing the generic method.
//
let ex = typeof<Example>
let mi = ex.GetMethod "Generic"

displayGenericMethodInfo mi

// Assign the int type to the type parameter of the Example
// method.
//
let miConstructed = mi.MakeGenericMethod typeof<int>

displayGenericMethodInfo miConstructed

// Invoke the method.
let args = [| box 42 |]
miConstructed.Invoke(null, args) |> ignore

// Invoke the method normally.
Example.Generic<int> 42

// Get the generic type definition from the closed method,
// and show it's the same as the original definition.
//
let miDef = miConstructed.GetGenericMethodDefinition()
printfn $"\r\nThe definition is the same: {miDef = mi}"

(* This example produces the following output:

--- Examine a generic method.

Void Generic[T](T)
        Is this a generic method definition? True
        Is it a generic method? True
        Does it have unassigned generic parameters? True
        List type arguments (1):
                T  parameter position 0
                   declaring method: Void Generic[T](T)

Void Generic[Int32](Int32)
        Is this a generic method definition? False
        Is it a generic method? True
        Does it have unassigned generic parameters? False
        List type arguments (1):
                System.Int32

Here it is: 42

Here it is: 42

The definition is the same: True

 *)

Imports System.Reflection

' Define a class with a generic method.
Public Class Example
    Public Shared Sub Generic(Of T)(ByVal toDisplay As T)
        Console.WriteLine(vbCrLf & "Here it is: {0}", toDisplay)
    End Sub
End Class

Public Class Test
    Public Shared Sub Main() 
        Console.WriteLine(vbCrLf & "--- Examine a generic method.")
        
        ' Create a Type object representing class Example, and
        ' get a MethodInfo representing the generic method.
        '
        Dim ex As Type = GetType(Example)
        Dim mi As MethodInfo = ex.GetMethod("Generic")
        
        DisplayGenericMethodInfo(mi)
        
        ' Assign the Integer type to the type parameter of the Example 
        ' method.
        '
        Dim arguments() As Type = { GetType(Integer) }
        Dim miConstructed As MethodInfo = mi.MakeGenericMethod(arguments)
        
        DisplayGenericMethodInfo(miConstructed)

        ' Invoke the method.
        Dim args() As Object = { 42 }
        miConstructed.Invoke(Nothing, args)
        
        ' Invoke the method normally.
        Example.Generic(Of Integer)(42)
        
        ' Get the generic type definition from the constructed method,
        ' and show that it's the same as the original definition.
        '
        Dim miDef As MethodInfo = miConstructed.GetGenericMethodDefinition()
        Console.WriteLine(vbCrLf & "The definition is the same: {0}", _
            miDef Is mi)
    End Sub
      
    Private Shared Sub DisplayGenericMethodInfo(ByVal mi As MethodInfo) 
        Console.WriteLine(vbCrLf & mi.ToString())
        
        Console.WriteLine(vbTab _
            & "Is this a generic method definition? {0}", _
            mi.IsGenericMethodDefinition)

        Console.WriteLine(vbTab & "Is it a generic method? {0}", _
            mi.IsGenericMethod)

        Console.WriteLine(vbTab _
            & "Does it have unassigned generic parameters? {0}", _
            mi.ContainsGenericParameters)

        ' If this is a generic method, display its type arguments.
        '
        If mi.IsGenericMethod Then
            Dim typeArguments As Type() = mi.GetGenericArguments()
            
            Console.WriteLine(vbTab & "List type arguments ({0}):", _
                typeArguments.Length)
            
            For Each tParam As Type In typeArguments
                ' IsGenericParameter is true only for generic type
                ' parameters.
                '
                If tParam.IsGenericParameter Then
                    Console.WriteLine(vbTab & vbTab _
                        & "{0}  parameter position: {1}" _
                        & vbCrLf & vbTab & vbTab _
                        & "   declaring method: {2}", _
                        tParam,  _
                        tParam.GenericParameterPosition, _
                        tParam.DeclaringMethod)
                Else
                    Console.WriteLine(vbTab & vbTab & tParam.ToString())
                End If
            Next tParam
        End If
    End Sub 
End Class 

' This example produces the following output:
'
'--- Examine a generic method.
'
'Void Generic[T](T)
'        Is this a generic method definition? True
'        Is it a generic method? True
'        Does it have unassigned generic parameters? True
'        List type arguments (1):
'                T  parameter position: 0
'                   declaring method: Void Generic[T](T)
'
'Void Generic[Int32](Int32)
'        Is this a generic method definition? False
'        Is it a generic method? True
'        Does it have unassigned generic parameters? False
'        List type arguments (1):
'                System.Int32
'
'Here it is: 42
'
'Here it is: 42
'
'The definition is the same: True
'

Keterangan

Metode deklarasikan adalah definisi metode generik. Artinya, jika DeclaringMethod tidak mengembalikan null, maka DeclaringMethod.IsGenericMethodDefinition mengembalikan true.

Properti DeclaringType dan DeclaringMethod mengidentifikasi definisi jenis generik atau definisi metode generik di mana parameter jenis generik awalnya ditentukan:

• DeclaringMethod Jika properti mengembalikan MethodInfo, yang MethodInfo mewakili definisi metode generik, dan objek saat ini Type mewakili parameter jenis definisi metode generik tersebut.

• DeclaringMethod Jika properti mengembalikan null, maka DeclaringType properti selalu mengembalikan objek yang Type mewakili definisi jenis generik, dan objek saat ini Type mewakili parameter jenis definisi jenis generik tersebut.

• DeclaringMethod Mendapatkan properti pada jenis yang propertinya IsGenericParameterfalse melempar InvalidOperationException.

MethodBase yang dikembalikan oleh DeclaringMethod properti adalah MethodInfo dalam kasus metode generik, atau ConstructorInfo dalam kasus konstruktor generik.

Nota

Di .NET Framework versi 2.0, konstruktor generik tidak didukung.

Untuk daftar ketentuan invarian untuk istilah yang digunakan dalam refleksi generik, lihat IsGenericType keterangan properti.

Lihat juga

• IsGenericParameter
• Refleksi dan Jenis Generik
• Cara: Memeriksa dan Membuat Instans Jenis Generik dengan Pantulan