Type.DeclaringMethod Eigenschaft
Definition
Wichtig
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Ruft eine MethodBase ab, die die deklarierende Methode darstellt, wenn der aktuelle Type einen Typparameter einer generischen Methode darstellt.
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
Eigenschaftswert
Wenn der aktuelle Type einen Typparameter einer generischen Methode darstellt, eine MethodBase, die die deklarierende Methode darstellt, andernfalls null
.
Beispiele
Im folgenden Codebeispiel wird eine Klasse definiert, die über eine generische Methode verfügt, der Methode ein Typargument zugewiesen und die resultierende konstruierte generische Methode aufgerufen. Außerdem werden Informationen zur generischen Methodendefinition und zur konstruierten Methode angezeigt. Beim Anzeigen von Informationen zu den Typparametern der generischen Methodendefinition zeigt der Beispielcode in der DisplayGenericMethodInfo
-Methode den Wert der DeclaringMethod -Eigenschaft für den generischen Typparameter der Methode an.
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
'
Hinweise
Die deklarierende Methode ist eine generische Methodendefinition. Das heißt, wenn DeclaringMethod nicht zurückgibt null
, wird zurückgegeben DeclaringMethod.IsGenericMethodDefinition
true
.
Die DeclaringType Eigenschaften und DeclaringMethod geben die generische Typdefinition oder die generische Methodendefinition an, in der der generische Typparameter ursprünglich definiert wurde:
Wenn die DeclaringMethod -Eigenschaft einen MethodInfozurückgibt, MethodInfo der eine generische Methodendefinition darstellt, und das aktuelle Type Objekt einen Typparameter dieser generischen Methodendefinition darstellt.
Wenn die DeclaringMethod -Eigenschaft zurückgibt
null
, gibt die -Eigenschaft immer ein Type Objekt zurück, das DeclaringType eine generische Typdefinition darstellt, und das aktuelle Type Objekt stellt einen Typparameter dieser generischen Typdefinition dar.Beim Abrufen der DeclaringMethod -Eigenschaft für einen Typ, dessen IsGenericParameter -Eigenschaft ausgelöst wird, wird
false
ein InvalidOperationExceptionausgelöst.
Das MethodBase von der DeclaringMethod -Eigenschaft zurückgegebene ist entweder im MethodInfo Fall einer generischen Methode oder im Fall eines generischen Konstruktors ein .ConstructorInfo
Hinweis
In der .NET Framework Version 2.0 werden generische Konstruktoren nicht unterstützt.
Eine Liste der invarianten Bedingungen für Begriffe, für Begriffe, die für die Reflektion mit generischen Methoden verwendet werden, finden Sie in den Hinweisen zur Eigenschaft IsGenericType.