Gets a MethodBase that represents the declaring method, if the current Type represents a type parameter of a generic method.
Assembly: mscorlib (in mscorlib.dll)
Public Overridable ReadOnly Property DeclaringMethod As MethodBasepublic virtual MethodBase DeclaringMethod { get; }public:
virtual property MethodBase^ DeclaringMethod {
MethodBase^ get ();
}abstract DeclaringMethod : MethodBase
override DeclaringMethod : MethodBaseProperty Value
Type: System.ReflectionIf the current Type represents a type parameter of a generic method, a MethodBase that represents declaring method; otherwise,
The declaring method is a generic method definition. That is, if DeclaringMethod does not return
The DeclaringType and DeclaringMethod properties identify the generic type definition or generic method definition in which the generic type parameter was originally defined:
If the DeclaringMethod property returns a MethodInfo, that MethodInfo represents a generic method definition, and the current Type object represents a type parameter of that generic method definition.
If the DeclaringMethod property returns
null Nothing nullptr a null reference (Nothing in Visual Basic) , then the DeclaringType property always returns a Type object representing a generic type definition, and the current Type object represents a type parameter of that generic type definition.Getting the DeclaringMethod property on a type whose IsGenericParameter property is false throws an InvalidOperationException.
The MethodBase that is returned by the DeclaringMethod property is either a MethodInfo in the case of a generic method, or a ConstructorInfo in the case of a generic constructor.
Note |
|---|
In the .NET Framework version 2.0, generic constructors are not supported. |
For a list of the invariant conditions for terms used in generic reflection, see the IsGenericType property remarks.
The following code example defines a class that has a generic method, assigns a type argument to the method, and invokes the resulting constructed generic method. It also displays information about the generic method definition and the constructed method. When displaying information about the type parameters of the generic method definition, in the DisplayGenericMethodInfo method, the example code shows the value of the DeclaringMethod property for the method's generic type parameter.
Imports System
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 'Main
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
'
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
*/
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
*/
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
Note