Type.DeclaringMethod Vlastnost
Definice
Důležité
Některé informace platí pro předběžně vydaný produkt, který se může zásadně změnit, než ho výrobce nebo autor vydá. Microsoft neposkytuje žádné záruky, výslovné ani předpokládané, týkající se zde uváděných informací.
Získá, MethodBase který představuje deklarující metodu, pokud aktuální Type představuje parametr typu obecné metody.
public:
virtual property System::Reflection::MethodBase ^ DeclaringMethod { System::Reflection::MethodBase ^ get(); };
public virtual System.Reflection.MethodBase? DeclaringMethod { get; }
public virtual System.Reflection.MethodBase DeclaringMethod { get; }
member this.DeclaringMethod : System.Reflection.MethodBase
Public Overridable ReadOnly Property DeclaringMethod As MethodBase
Hodnota vlastnosti
Pokud aktuální Type představuje parametr typu obecné metody, představuje deklarující metodu MethodBase , jinak null
.
Příklady
Následující příklad kódu definuje třídu, která má obecnou metodu, přiřadí argument typu metodě a vyvolá výslednou vytvořenou obecnou metodu. Zobrazuje také informace o definici obecné metody a vytvořené metodě. Při zobrazení informací o parametrech typu definice obecné metody v DisplayGenericMethodInfo
metodě ukázkový kód zobrazuje hodnotu DeclaringMethod vlastnosti parametru obecného typu metody.
using namespace System;
using namespace System::Reflection;
// Define a class with a generic method.
ref class Example
{
public:
generic<typename T> static void Generic(T toDisplay)
{
Console::WriteLine("\r\nHere it is: {0}", toDisplay);
}
};
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)
{
array<Type^>^ typeArguments = mi->GetGenericArguments();
Console::WriteLine("\tList type arguments ({0}):",
typeArguments->Length);
for each (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);
}
}
}
};
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 = Example::typeid;
MethodInfo^ mi = ex->GetMethod("Generic");
DisplayGenericMethodInfo(mi);
// Assign the int type to the type parameter of the Example
// method.
//
MethodInfo^ miConstructed = mi->MakeGenericMethod(int::typeid);
DisplayGenericMethodInfo(miConstructed);
// Invoke the method.
array<Object^>^ args = { 42 };
miConstructed->Invoke((Object^) 0, 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);
};
/* 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
*/
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
'
Poznámky
Deklarující metoda je definice obecné metody. To znamená, že pokud DeclaringMethod nevrátí null
, vrátí DeclaringMethod.IsGenericMethodDefinition
.true
Vlastnosti DeclaringType a DeclaringMethod identifikují definici obecného typu nebo definice obecné metody, ve které byl parametr obecného typu původně definován:
DeclaringMethod Pokud vlastnost vrátí MethodInfo, představuje MethodInfo definici obecné metody a aktuální Type objekt představuje parametr typu této definice obecné metody.
DeclaringMethod Pokud vlastnost vrátí
null
, vrátí DeclaringType vlastnost vždy Type objekt představující definici obecného typu a aktuální Type objekt představuje parametr typu této definice obecného typu.DeclaringMethod Získání vlastnosti pro typ, jehož IsGenericParameter vlastnost je
false
, vyvolá .InvalidOperationException
Vlastnost MethodBase je vrácena DeclaringMethod buď MethodInfo v případě obecné metody, nebo v případě obecného konstruktoru ConstructorInfo .
Poznámka
V rozhraní .NET Framework verze 2.0 nejsou obecné konstruktory podporovány.
Seznam invariantních podmínek pro termíny použité v obecné reflexi najdete v poznámkách k IsGenericType vlastnostem.