Attribute.IsDefined Method
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
Determines whether any custom attributes of a specified type are applied to an assembly, module, type member, or method parameter.
Overloads
IsDefined(ParameterInfo, Type, Boolean) |
Determines whether any custom attributes are applied to a method parameter. Parameters specify the method parameter, the type of the custom attribute to search for, and whether to search ancestors of the method parameter. |
IsDefined(Module, Type, Boolean) |
Determines whether any custom attributes are applied to a module. Parameters specify the module, the type of the custom attribute to search for, and an ignored search option. |
IsDefined(MemberInfo, Type, Boolean) |
Determines whether any custom attributes are applied to a member of a type. Parameters specify the member, the type of the custom attribute to search for, and whether to search ancestors of the member. |
IsDefined(Assembly, Type, Boolean) |
Determines whether any custom attributes are applied to an assembly. Parameters specify the assembly, the type of the custom attribute to search for, and an ignored search option. |
IsDefined(MemberInfo, Type) |
Determines whether any custom attributes are applied to a member of a type. Parameters specify the member, and the type of the custom attribute to search for. |
IsDefined(Module, Type) |
Determines whether any custom attributes of a specified type are applied to a module. Parameters specify the module, and the type of the custom attribute to search for. |
IsDefined(Assembly, Type) |
Determines whether any custom attributes are applied to an assembly. Parameters specify the assembly, and the type of the custom attribute to search for. |
IsDefined(ParameterInfo, Type) |
Determines whether any custom attributes are applied to a method parameter. Parameters specify the method parameter, and the type of the custom attribute to search for. |
IsDefined(ParameterInfo, Type, Boolean)
- Source:
- Attribute.CoreCLR.cs
- Source:
- Attribute.CoreCLR.cs
- Source:
- Attribute.CoreCLR.cs
Determines whether any custom attributes are applied to a method parameter. Parameters specify the method parameter, the type of the custom attribute to search for, and whether to search ancestors of the method parameter.
public:
static bool IsDefined(System::Reflection::ParameterInfo ^ element, Type ^ attributeType, bool inherit);
public static bool IsDefined (System.Reflection.ParameterInfo element, Type attributeType, bool inherit);
static member IsDefined : System.Reflection.ParameterInfo * Type * bool -> bool
Public Shared Function IsDefined (element As ParameterInfo, attributeType As Type, inherit As Boolean) As Boolean
Parameters
- element
- ParameterInfo
An object derived from the ParameterInfo class that describes a parameter of a member of a class.
- attributeType
- Type
The type, or a base type, of the custom attribute to search for.
- inherit
- Boolean
If true
, specifies to also search the ancestors of element
for custom attributes.
Returns
true
if a custom attribute of type attributeType
is applied to element
; otherwise, false
.
Exceptions
element
or attributeType
is null
.
attributeType
is not derived from Attribute.
element
is not a method, constructor, or type.
Examples
The following code example illustrates the use of IsDefined, taking a ParameterInfo as a parameter.
using namespace System;
using namespace System::Reflection;
namespace IsDef5CS
{
public ref class TestClass
{
public:
// Assign a ParamArray attribute to the parameter using the keyword.
void Method1(... array<String^>^args ){}
};
ref class DemoClass
{
public:
static void Main()
{
// Get the class type to access its metadata.
Type^ clsType = TestClass::typeid;
// Get the MethodInfo object for Method1.
MethodInfo^ mInfo = clsType->GetMethod( "Method1" );
// Get the ParameterInfo array for the method parameters.
array<ParameterInfo^>^pInfo = mInfo->GetParameters();
if ( pInfo != nullptr )
{
// See if the ParamArray attribute is defined.
bool isDef = Attribute::IsDefined( pInfo[ 0 ], ParamArrayAttribute::typeid );
// Display the result.
Console::WriteLine( "The ParamArray attribute {0} defined for "
"parameter {1} of method {2}.", isDef ? (String^)"is" : "is not", pInfo[ 0 ]->Name, mInfo->Name );
}
else
Console::WriteLine( "The parameters information could "
"not be retrieved for method {0}.", mInfo->Name );
}
};
}
/*
* Output:
* The ParamArray attribute is defined for parameter args of method Method1.
*/
using System;
using System.Reflection;
namespace IsDef5CS
{
public class TestClass
{
// Assign a ParamArray attribute to the parameter using the keyword.
public void Method1(params String[] args)
{}
}
public class DemoClass
{
static void Main(string[] args)
{
// Get the class type to access its metadata.
Type clsType = typeof(TestClass);
// Get the MethodInfo object for Method1.
MethodInfo mInfo = clsType.GetMethod("Method1");
// Get the ParameterInfo array for the method parameters.
ParameterInfo[] pInfo = mInfo.GetParameters();
if (pInfo != null)
{
// See if the ParamArray attribute is defined.
bool isDef = Attribute.IsDefined(pInfo[0],
typeof(ParamArrayAttribute));
// Display the result.
Console.WriteLine("The ParamArray attribute {0} defined for " +
"parameter {1} of method {2}.",
isDef ? "is" : "is not",
pInfo[0].Name,
mInfo.Name);
}
else
Console.WriteLine("The parameters information could " +
"not be retrieved for method {0}.", mInfo.Name);
}
}
}
/*
* Output:
* The ParamArray attribute is defined for parameter args of method Method1.
*/
open System;
type TestClass() =
// Assign a ParamArray attribute to the parameter.
member _.Method1([<ParamArray>] args: string[]) = ()
// Get the class type to access its metadata.
let clsType = typeof<TestClass>
// Get the MethodInfo object for Method1.
let mInfo = clsType.GetMethod "Method1"
// Get the ParameterInfo array for the method parameters.
let pInfo = mInfo.GetParameters()
if pInfo <> null then
// See if the ParamArray attribute is defined.
let isDef = Attribute.IsDefined(pInfo[0], typeof<ParamArrayAttribute>)
// Display the result.
printfn $"""The ParamArray attribute {if isDef then "is" else "is not"} defined for parameter {pInfo[0].Name} of method {mInfo.Name}."""
else
printfn $"The parameters information could not be retrieved for method {mInfo.Name}."
// Output:
// The ParamArray attribute is defined for parameter args of method Method1.
Imports System.Reflection
Module DemoModule
Public Class TestClass
' Assign a ParamArray attribute to the parameter using the keyword.
Public Sub Method1(ByVal ParamArray args As String())
End Sub
End Class
Sub Main()
' Get the class type to access its metadata.
Dim clsType As Type = GetType(TestClass)
' Get the MethodInfo object for Method1.
Dim mInfo As MethodInfo = clsType.GetMethod("Method1")
' Get the ParameterInfo array for the method parameters.
Dim pInfo() As ParameterInfo = mInfo.GetParameters()
If Not pInfo(0) Is Nothing Then
' See if the ParamArray attribute is defined.
Dim isDef As Boolean = Attribute.IsDefined(pInfo(0), _
GetType(ParamArrayAttribute))
Dim strDef As String
If isDef = True Then
strDef = "is"
Else
strDef = "is not"
End If
' Display the result.
Console.WriteLine("The ParamArray attribute {0} defined " & _
"for parameter {1} of method {2}.", _
strDef, pInfo(0).Name, mInfo.Name)
Else
Console.WriteLine("Could not retrieve parameter information " & _
"for method {0}.", mInfo.Name)
End If
End Sub
End Module
' Output:
' The ParamArray attribute is defined for parameter args of method Method1.
Applies to
IsDefined(Module, Type, Boolean)
- Source:
- Attribute.CoreCLR.cs
- Source:
- Attribute.CoreCLR.cs
- Source:
- Attribute.CoreCLR.cs
Determines whether any custom attributes are applied to a module. Parameters specify the module, the type of the custom attribute to search for, and an ignored search option.
public:
static bool IsDefined(System::Reflection::Module ^ element, Type ^ attributeType, bool inherit);
public static bool IsDefined (System.Reflection.Module element, Type attributeType, bool inherit);
static member IsDefined : System.Reflection.Module * Type * bool -> bool
Public Shared Function IsDefined (element As Module, attributeType As Type, inherit As Boolean) As Boolean
Parameters
- attributeType
- Type
The type, or a base type, of the custom attribute to search for.
- inherit
- Boolean
This parameter is ignored, and does not affect the operation of this method.
Returns
true
if a custom attribute of type attributeType
is applied to element
; otherwise, false
.
Exceptions
element
or attributeType
is null
.
attributeType
is not derived from Attribute.
Examples
The following code example illustrates the use of IsDefined, taking a Module as a parameter.
using namespace System;
using namespace System::Diagnostics;
// Add the Debuggable attribute to the module.
[module:Debuggable(true,false)];
namespace IsDef2CS
{
ref class DemoClass
{
public:
static void Main()
{
// Get the class type to access its metadata.
Type^ clsType = DemoClass::typeid;
// See if the Debuggable attribute is defined for this module.
bool isDef = Attribute::IsDefined( clsType->Module, DebuggableAttribute::typeid );
// Display the result.
Console::WriteLine( "The Debuggable attribute {0} "
"defined for Module {1}.", isDef ? (String^)"is" : "is not", clsType->Module->Name );
// If the attribute is defined, display the JIT settings.
if ( isDef )
{
// Retrieve the attribute itself.
DebuggableAttribute^ dbgAttr = dynamic_cast<DebuggableAttribute^>(Attribute::GetCustomAttribute( clsType->Module, DebuggableAttribute::typeid ));
if ( dbgAttr != nullptr )
{
Console::WriteLine( "JITTrackingEnabled is {0}.", dbgAttr->IsJITTrackingEnabled );
Console::WriteLine( "JITOptimizerDisabled is {0}.", dbgAttr->IsJITOptimizerDisabled );
}
else
Console::WriteLine( "The Debuggable attribute "
"could not be retrieved." );
}
}
};
}
/*
* Output:
* The Debuggable attribute is defined for Module IsDef2CS.exe.
* JITTrackingEnabled is True.
* JITOptimizerDisabled is False.
*/
using System;
using System.Diagnostics;
// Add the Debuggable attribute to the module.
[module:Debuggable(true, false)]
namespace IsDef2CS
{
public class DemoClass
{
static void Main(string[] args)
{
// Get the class type to access its metadata.
Type clsType = typeof(DemoClass);
// See if the Debuggable attribute is defined for this module.
bool isDef = Attribute.IsDefined(clsType.Module,
typeof(DebuggableAttribute));
// Display the result.
Console.WriteLine("The Debuggable attribute {0} " +
"defined for Module {1}.",
isDef ? "is" : "is not",
clsType.Module.Name);
// If the attribute is defined, display the JIT settings.
if (isDef)
{
// Retrieve the attribute itself.
DebuggableAttribute dbgAttr = (DebuggableAttribute)
Attribute.GetCustomAttribute(clsType.Module,
typeof(DebuggableAttribute));
if (dbgAttr != null)
{
Console.WriteLine("JITTrackingEnabled is {0}.",
dbgAttr.IsJITTrackingEnabled);
Console.WriteLine("JITOptimizerDisabled is {0}.",
dbgAttr.IsJITOptimizerDisabled);
}
else
Console.WriteLine("The Debuggable attribute " +
"could not be retrieved.");
}
}
}
}
/*
* Output:
* The Debuggable attribute is defined for Module IsDef2CS.exe.
* JITTrackingEnabled is True.
* JITOptimizerDisabled is False.
*/
open System
open System.Diagnostics
// Add the Debuggable attribute to the module.
[<``module``: Debuggable(true, false)>]
do ()
type DemoClass = class end
// Get the class type to access its metadata.
let clsType = typeof<DemoClass>
// See if the Debuggable attribute is defined for this module.
let isDef = Attribute.IsDefined(clsType.Module, typeof<DebuggableAttribute>)
// Display the result.
printfn $"""The Debuggable attribute {if isDef then "is" else "is not"} defined for Module {clsType.Module.Name}."""
// If the attribute is defined, display the JIT settings.
if isDef then
// Retrieve the attribute itself.
let dbgAttr =
Attribute.GetCustomAttribute(clsType.Module, typeof<DebuggableAttribute>)
:?> DebuggableAttribute
if dbgAttr <> null then
printfn $"JITTrackingEnabled is {dbgAttr.IsJITTrackingEnabled}."
printfn $"JITOptimizerDisabled is {dbgAttr.IsJITOptimizerDisabled}."
else
printfn "The Debuggable attribute could not be retrieved."
// Output:
// The Debuggable attribute is defined for Module IsDef2CS.exe.
// JITTrackingEnabled is True.
// JITOptimizerDisabled is False.
Imports System.Reflection
Imports System.Diagnostics
' Add the Debuggable attribute to the module.
<Module: Debuggable(True, False)>
Module DemoModule
Sub Main()
' Get the module type information to access its metadata.
Dim modType As Type = GetType(DemoModule)
' See if the Debuggable attribute is defined.
Dim isDef As Boolean = Attribute.IsDefined(modType.Module, _
GetType(DebuggableAttribute))
Dim strDef As String
If isDef = True Then
strDef = "is"
Else
strDef = "is not"
End If
' Display the result
Console.WriteLine("The debuggable attribute {0} defined for " & _
"module {1}.", strDef, modType.Name)
' If the attribute is defined, display the JIT settings.
If isDef = True Then
' Retrieve the attribute itself.
Dim attr As Attribute = _
Attribute.GetCustomAttribute(modType.Module, _
GetType(DebuggableAttribute))
If Not attr Is Nothing And TypeOf attr Is DebuggableAttribute Then
Dim dbgAttr As DebuggableAttribute = _
CType(attr, DebuggableAttribute)
Console.WriteLine("JITTrackingEnabled is {0}.", _
dbgAttr.IsJITTrackingEnabled.ToString())
Console.WriteLine("JITOptimizerDisabled is {0}.", _
dbgAttr.IsJITOptimizerDisabled.ToString())
Else
Console.WriteLine("The Debuggable attribute could " & _
"not be retrieved.")
End If
End If
End Sub
End Module
' Output:
' The debuggable attribute is defined for module DemoModule.
' JITTrackingEnabled is True.
' JITOptimizerDisabled is False.
Remarks
This method ignores the inherit
parameter and does not search the ancestors of element
for custom attributes.
Applies to
IsDefined(MemberInfo, Type, Boolean)
- Source:
- Attribute.CoreCLR.cs
- Source:
- Attribute.CoreCLR.cs
- Source:
- Attribute.CoreCLR.cs
Determines whether any custom attributes are applied to a member of a type. Parameters specify the member, the type of the custom attribute to search for, and whether to search ancestors of the member.
public:
static bool IsDefined(System::Reflection::MemberInfo ^ element, Type ^ attributeType, bool inherit);
public static bool IsDefined (System.Reflection.MemberInfo element, Type attributeType, bool inherit);
static member IsDefined : System.Reflection.MemberInfo * Type * bool -> bool
Public Shared Function IsDefined (element As MemberInfo, attributeType As Type, inherit As Boolean) As Boolean
Parameters
- element
- MemberInfo
An object derived from the MemberInfo class that describes a constructor, event, field, method, type, or property member of a class.
- attributeType
- Type
The type, or a base type, of the custom attribute to search for.
- inherit
- Boolean
If true
, specifies to also search the ancestors of element
for custom attributes.
Returns
true
if a custom attribute of type attributeType
is applied to element
; otherwise, false
.
Exceptions
element
or attributeType
is null
.
attributeType
is not derived from Attribute.
element
is not a constructor, method, property, event, type, or field.
Examples
The following code example illustrates the use of IsDefined, taking a MemberInfo as a parameter.
using namespace System;
using namespace System::Reflection;
namespace IsDef4CS
{
public ref class TestClass
{
public:
// Assign the Obsolete attribute to a method.
[Obsolete("This method is obsolete. Use Method2 instead.")]
void Method1(){}
void Method2(){}
};
ref class DemoClass
{
public:
static void Main()
{
// Get the class type to access its metadata.
Type^ clsType = TestClass::typeid;
// Get the MethodInfo object for Method1.
MethodInfo^ mInfo = clsType->GetMethod( "Method1" );
// See if the Obsolete attribute is defined for this method.
bool isDef = Attribute::IsDefined( mInfo, ObsoleteAttribute::typeid );
// Display the result.
Console::WriteLine( "The Obsolete Attribute {0} defined for {1} of class {2}.", isDef ? (String^)"is" : "is not", mInfo->Name, clsType->Name );
// If it's defined, display the attribute's message.
if ( isDef )
{
ObsoleteAttribute^ obsAttr = dynamic_cast<ObsoleteAttribute^>(Attribute::GetCustomAttribute( mInfo, ObsoleteAttribute::typeid ));
if ( obsAttr != nullptr )
Console::WriteLine( "The message is: \"{0}\".", obsAttr->Message );
else
Console::WriteLine( "The message could not be retrieved." );
}
}
};
}
/*
* Output:
* The Obsolete Attribute is defined for Method1 of class TestClass.
* The message is: "This method is obsolete. Use Method2 instead.".
*/
using System;
using System.Reflection;
namespace IsDef4CS
{
public class TestClass
{
// Assign the Obsolete attribute to a method.
[Obsolete("This method is obsolete. Use Method2 instead.")]
public void Method1()
{}
public void Method2()
{}
}
public class DemoClass
{
static void Main(string[] args)
{
// Get the class type to access its metadata.
Type clsType = typeof(TestClass);
// Get the MethodInfo object for Method1.
MethodInfo mInfo = clsType.GetMethod("Method1");
// See if the Obsolete attribute is defined for this method.
bool isDef = Attribute.IsDefined(mInfo, typeof(ObsoleteAttribute));
// Display the result.
Console.WriteLine("The Obsolete Attribute {0} defined for {1} of class {2}.",
isDef ? "is" : "is not", mInfo.Name, clsType.Name);
// If it's defined, display the attribute's message.
if (isDef)
{
ObsoleteAttribute obsAttr =
(ObsoleteAttribute)Attribute.GetCustomAttribute(
mInfo, typeof(ObsoleteAttribute));
if (obsAttr != null)
Console.WriteLine("The message is: \"{0}\".",
obsAttr.Message);
else
Console.WriteLine("The message could not be retrieved.");
}
}
}
}
/*
* Output:
* The Obsolete Attribute is defined for Method1 of class TestClass.
* The message is: "This method is obsolete. Use Method2 instead.".
*/
open System
type TestClass() =
// Assign the Obsolete attribute to a method.
[<Obsolete "This method is obsolete. Use Method2 instead.">]
member _.Method1() = ()
member _.Method2() = ()
// Get the class type to access its metadata.
let clsType = typeof<TestClass>
// Get the MethodInfo object for Method1.
let mInfo = clsType.GetMethod "Method1"
// See if the Obsolete attribute is defined for this method.
let isDef = Attribute.IsDefined(mInfo, typeof<ObsoleteAttribute>)
// Display the result.
printfn $"""The Obsolete Attribute {if isDef then "is" else "is not"} defined for {mInfo.Name} of class {clsType.Name}."""
// If it's defined, display the attribute's message.
if isDef then
let obsAttr =
Attribute.GetCustomAttribute(mInfo, typeof<ObsoleteAttribute>)
:?> ObsoleteAttribute
if obsAttr <> null then
printfn $"The message is: \"{obsAttr.Message}\"."
else
printfn "The message could not be retrieved."
// Output:
// The Obsolete Attribute is defined for Method1 of class TestClass.
// The message is: "This method is obsolete. Use Method2 instead.".
Imports System.Reflection
Module DemoModule
Public Class TestClass
' Assign the Obsolete attribute to a method.
<Obsolete("This method is obsolete. Use Method2() instead.")> _
Public Sub Method1()
End Sub
Public Sub Method2()
End Sub
End Class
Sub Main()
' Get the class type to access its metadata.
Dim clsType As Type = GetType(TestClass)
' Get the MethodInfo object for Method1.
Dim mInfo As MethodInfo = clsType.GetMethod("Method1")
' See if the Obsolete attribute is defined for this method.
Dim isDef As Boolean = Attribute.IsDefined(mInfo, _
GetType(ObsoleteAttribute))
Dim strDef As String
If isDef = True Then
strDef = "is"
Else
strDef = "is not"
End If
' Display the results.
Console.WriteLine("The Obsolete attribute {0} defined for " & _
"method {1} of class {2}.", strDef, mInfo.Name, clsType.Name)
' If it's defined, display the attribute's message.
If isDef = True Then
Dim attr As Attribute = Attribute.GetCustomAttribute(mInfo, _
GetType(ObsoleteAttribute))
If Not attr Is Nothing And TypeOf attr Is ObsoleteAttribute Then
Dim obsAttr As ObsoleteAttribute = _
CType(attr, ObsoleteAttribute)
Console.WriteLine("The message is: ""{0}""", obsAttr.Message)
Else
Console.WriteLine("The message could not be retrieved.")
End If
End If
End Sub
End Module
' Output:
' The Obsolete attribute is defined for method Method1 of class TestClass.
' The message is: "This method is obsolete. Use Method2() instead."
Remarks
Note
Starting with the .NET Framework version 2.0, this method returns true
if a type, method, or constructor has security attributes stored in the new metadata format. Assemblies compiled with version 2.0 or later use the new format. Dynamic assemblies and assemblies compiled with earlier versions of the .NET Framework use the old XML format. See Emitting Declarative Security Attributes.
Applies to
IsDefined(Assembly, Type, Boolean)
- Source:
- Attribute.CoreCLR.cs
- Source:
- Attribute.CoreCLR.cs
- Source:
- Attribute.CoreCLR.cs
Determines whether any custom attributes are applied to an assembly. Parameters specify the assembly, the type of the custom attribute to search for, and an ignored search option.
public:
static bool IsDefined(System::Reflection::Assembly ^ element, Type ^ attributeType, bool inherit);
public static bool IsDefined (System.Reflection.Assembly element, Type attributeType, bool inherit);
static member IsDefined : System.Reflection.Assembly * Type * bool -> bool
Public Shared Function IsDefined (element As Assembly, attributeType As Type, inherit As Boolean) As Boolean
Parameters
- element
- Assembly
An object derived from the Assembly class that describes a reusable collection of modules.
- attributeType
- Type
The type, or a base type, of the custom attribute to search for.
- inherit
- Boolean
This parameter is ignored, and does not affect the operation of this method.
Returns
true
if a custom attribute of type attributeType
is applied to element
; otherwise, false
.
Exceptions
element
or attributeType
is null
.
attributeType
is not derived from Attribute.
Examples
The following code example illustrates the use of IsDefined, taking an Assembly as a parameter.
using namespace System;
using namespace System::Reflection;
// Add an AssemblyDescription attribute
[assembly:AssemblyDescription("A sample description")];
namespace IsDef1CS
{
ref class DemoClass
{
public:
static void Main()
{
// Get the class type to access its metadata.
Type^ clsType = DemoClass::typeid;
// Get the assembly object.
Assembly^ assy = clsType->Assembly;
// Store the assembly's name.
String^ assyName = assy->GetName()->Name;
//Type assyType = assy.GetType();
// See if the Assembly Description is defined.
bool isdef = Attribute::IsDefined( assy, AssemblyDescriptionAttribute::typeid );
if ( isdef )
{
// Affirm that the attribute is defined.
Console::WriteLine( "The AssemblyDescription attribute "
"is defined for assembly {0}.", assyName );
// Get the description attribute itself.
AssemblyDescriptionAttribute^ adAttr = dynamic_cast<AssemblyDescriptionAttribute^>(Attribute::GetCustomAttribute( assy, AssemblyDescriptionAttribute::typeid ));
// Display the description.
if ( adAttr != nullptr )
Console::WriteLine( "The description is \"{0}\".", adAttr->Description );
else
Console::WriteLine( "The description could not "
"be retrieved." );
}
else
Console::WriteLine( "The AssemblyDescription attribute is not "
"defined for assembly {0}.", assyName );
}
};
}
/*
* Output:
* The AssemblyDescription attributeis defined for assembly IsDef1CS.
* The description is "A sample description".
*/
using System;
using System.Reflection;
// Add an AssemblyDescription attribute
[assembly: AssemblyDescription("A sample description")]
namespace IsDef1CS
{
public class DemoClass
{
static void Main(string[] args)
{
// Get the class type to access its metadata.
Type clsType = typeof(DemoClass);
// Get the assembly object.
Assembly assy = clsType.Assembly;
// Store the assembly's name.
String assyName = assy.GetName().Name;
// See if the Assembly Description is defined.
bool isdef = Attribute.IsDefined(assy,
typeof(AssemblyDescriptionAttribute));
if (isdef)
{
// Affirm that the attribute is defined.
Console.WriteLine("The AssemblyDescription attribute " +
"is defined for assembly {0}.", assyName);
// Get the description attribute itself.
AssemblyDescriptionAttribute adAttr =
(AssemblyDescriptionAttribute)Attribute.GetCustomAttribute(
assy, typeof(AssemblyDescriptionAttribute));
// Display the description.
if (adAttr != null)
Console.WriteLine("The description is \"{0}\".",
adAttr.Description);
else
Console.WriteLine("The description could not " +
"be retrieved.");
}
else
Console.WriteLine("The AssemblyDescription attribute is not " +
"defined for assembly {0}.", assyName);
}
}
}
/*
* Output:
* The AssemblyDescription attribute is defined for assembly IsDef1CS.
* The description is "A sample description".
*/
open System
open System.Reflection
// Add an AssemblyDescription attribute
[<assembly: AssemblyDescription "A sample description">]
do ()
type DemoClass = class end
// Get the class type to access its metadata.
let clsType = typeof<DemoClass>
// Get the assembly object.
let assembly = clsType.Assembly;
// Store the assembly's name.
let assemblyName = assembly.GetName().Name
// See if the Assembly Description is defined.
let isdef =
Attribute.IsDefined(assembly, typeof<AssemblyDescriptionAttribute>)
if isdef then
// Affirm that the attribute is defined.
printfn $"The AssemblyDescription attribute is defined for assembly {assemblyName}."
// Get the description attribute itself.
let adAttr =
Attribute.GetCustomAttribute(assembly, typeof<AssemblyDescriptionAttribute>)
:?> AssemblyDescriptionAttribute
// Display the description.
if adAttr <> null then
printfn $"The description is \"{adAttr.Description}\"."
else
printfn $"The description could not be retrieved."
else
printfn $"The AssemblyDescription attribute is not defined for assembly {assemblyName}."
// Output:
// The AssemblyDescription attribute is defined for assembly IsDef1FS.
// The description is "A sample description".
Imports System.Reflection
' Add an AssemblyDescription attribute.
<Assembly: AssemblyDescription("A sample description")>
Module DemoModule
Sub Main()
' Get the assembly for this module.
Dim assy As System.Reflection.Assembly = GetType(DemoModule).Assembly
' Store the assembly name.
Dim assyName As String = assy.GetName().Name
' See if the AssemblyDescription attribute is defined.
If Attribute.IsDefined(assy, GetType(AssemblyDescriptionAttribute)) _
Then
' Affirm that the attribute is defined. Assume the filename of
' this code example is "IsDef1VB".
Console.WriteLine("The AssemblyDescription attribute is " & _
"defined for assembly {0}.", assyName)
' Get the description attribute itself.
Dim attr As Attribute = Attribute.GetCustomAttribute( _
assy, GetType(AssemblyDescriptionAttribute))
' Display the description.
If Not attr Is Nothing And _
TypeOf attr Is AssemblyDescriptionAttribute Then
Dim adAttr As AssemblyDescriptionAttribute = _
CType(attr, AssemblyDescriptionAttribute)
Console.WriteLine("The description is " & _
Chr(34) & "{0}" & Chr(34) & ".", adAttr.Description)
Else
Console.WriteLine("The description could not be retrieved.")
End If
Else
Console.WriteLine("The AssemblyDescription attribute is not " & _
"defined for assembly {0}.", assyName)
End If
End Sub
End Module
' Output:
' The AssemblyDescription attribute is defined for assembly IsDef1VB.
' The description is "A sample description".
Remarks
Note
Starting with the .NET Framework version 2.0, this method returns true
if the assembly has security attributes stored in the new metadata format. Assemblies compiled with version 2.0 or later use the new format. Dynamic assemblies and assemblies compiled with earlier versions of the .NET Framework use the old XML format. See Emitting Declarative Security Attributes.
Applies to
IsDefined(MemberInfo, Type)
- Source:
- Attribute.CoreCLR.cs
- Source:
- Attribute.CoreCLR.cs
- Source:
- Attribute.CoreCLR.cs
Determines whether any custom attributes are applied to a member of a type. Parameters specify the member, and the type of the custom attribute to search for.
public:
static bool IsDefined(System::Reflection::MemberInfo ^ element, Type ^ attributeType);
public static bool IsDefined (System.Reflection.MemberInfo element, Type attributeType);
static member IsDefined : System.Reflection.MemberInfo * Type -> bool
Public Shared Function IsDefined (element As MemberInfo, attributeType As Type) As Boolean
Parameters
- element
- MemberInfo
An object derived from the MemberInfo class that describes a constructor, event, field, method, type, or property member of a class.
- attributeType
- Type
The type, or a base type, of the custom attribute to search for.
Returns
true
if a custom attribute of type attributeType
is applied to element
; otherwise, false
.
Exceptions
element
or attributeType
is null
.
attributeType
is not derived from Attribute.
element
is not a constructor, method, property, event, type, or field.
Examples
The following code example illustrates the use of IsDefined, taking a MemberInfo as a parameter.
using namespace System;
using namespace System::Reflection;
namespace IsDef4CS
{
public ref class TestClass
{
public:
// Assign the Obsolete attribute to a method.
[Obsolete("This method is obsolete. Use Method2 instead.")]
void Method1(){}
void Method2(){}
};
ref class DemoClass
{
public:
static void Main()
{
// Get the class type to access its metadata.
Type^ clsType = TestClass::typeid;
// Get the MethodInfo object for Method1.
MethodInfo^ mInfo = clsType->GetMethod( "Method1" );
// See if the Obsolete attribute is defined for this method.
bool isDef = Attribute::IsDefined( mInfo, ObsoleteAttribute::typeid );
// Display the result.
Console::WriteLine( "The Obsolete Attribute {0} defined for {1} of class {2}.", isDef ? (String^)"is" : "is not", mInfo->Name, clsType->Name );
// If it's defined, display the attribute's message.
if ( isDef )
{
ObsoleteAttribute^ obsAttr = dynamic_cast<ObsoleteAttribute^>(Attribute::GetCustomAttribute( mInfo, ObsoleteAttribute::typeid ));
if ( obsAttr != nullptr )
Console::WriteLine( "The message is: \"{0}\".", obsAttr->Message );
else
Console::WriteLine( "The message could not be retrieved." );
}
}
};
}
/*
* Output:
* The Obsolete Attribute is defined for Method1 of class TestClass.
* The message is: "This method is obsolete. Use Method2 instead.".
*/
using System;
using System.Reflection;
namespace IsDef4CS
{
public class TestClass
{
// Assign the Obsolete attribute to a method.
[Obsolete("This method is obsolete. Use Method2 instead.")]
public void Method1()
{}
public void Method2()
{}
}
public class DemoClass
{
static void Main(string[] args)
{
// Get the class type to access its metadata.
Type clsType = typeof(TestClass);
// Get the MethodInfo object for Method1.
MethodInfo mInfo = clsType.GetMethod("Method1");
// See if the Obsolete attribute is defined for this method.
bool isDef = Attribute.IsDefined(mInfo, typeof(ObsoleteAttribute));
// Display the result.
Console.WriteLine("The Obsolete Attribute {0} defined for {1} of class {2}.",
isDef ? "is" : "is not", mInfo.Name, clsType.Name);
// If it's defined, display the attribute's message.
if (isDef)
{
ObsoleteAttribute obsAttr =
(ObsoleteAttribute)Attribute.GetCustomAttribute(
mInfo, typeof(ObsoleteAttribute));
if (obsAttr != null)
Console.WriteLine("The message is: \"{0}\".",
obsAttr.Message);
else
Console.WriteLine("The message could not be retrieved.");
}
}
}
}
/*
* Output:
* The Obsolete Attribute is defined for Method1 of class TestClass.
* The message is: "This method is obsolete. Use Method2 instead.".
*/
open System
type TestClass() =
// Assign the Obsolete attribute to a method.
[<Obsolete "This method is obsolete. Use Method2 instead.">]
member _.Method1() = ()
member _.Method2() = ()
// Get the class type to access its metadata.
let clsType = typeof<TestClass>
// Get the MethodInfo object for Method1.
let mInfo = clsType.GetMethod "Method1"
// See if the Obsolete attribute is defined for this method.
let isDef = Attribute.IsDefined(mInfo, typeof<ObsoleteAttribute>)
// Display the result.
printfn $"""The Obsolete Attribute {if isDef then "is" else "is not"} defined for {mInfo.Name} of class {clsType.Name}."""
// If it's defined, display the attribute's message.
if isDef then
let obsAttr =
Attribute.GetCustomAttribute(mInfo, typeof<ObsoleteAttribute>)
:?> ObsoleteAttribute
if obsAttr <> null then
printfn $"The message is: \"{obsAttr.Message}\"."
else
printfn "The message could not be retrieved."
// Output:
// The Obsolete Attribute is defined for Method1 of class TestClass.
// The message is: "This method is obsolete. Use Method2 instead.".
Imports System.Reflection
Module DemoModule
Public Class TestClass
' Assign the Obsolete attribute to a method.
<Obsolete("This method is obsolete. Use Method2() instead.")> _
Public Sub Method1()
End Sub
Public Sub Method2()
End Sub
End Class
Sub Main()
' Get the class type to access its metadata.
Dim clsType As Type = GetType(TestClass)
' Get the MethodInfo object for Method1.
Dim mInfo As MethodInfo = clsType.GetMethod("Method1")
' See if the Obsolete attribute is defined for this method.
Dim isDef As Boolean = Attribute.IsDefined(mInfo, _
GetType(ObsoleteAttribute))
Dim strDef As String
If isDef = True Then
strDef = "is"
Else
strDef = "is not"
End If
' Display the results.
Console.WriteLine("The Obsolete attribute {0} defined for " & _
"method {1} of class {2}.", strDef, mInfo.Name, clsType.Name)
' If it's defined, display the attribute's message.
If isDef = True Then
Dim attr As Attribute = Attribute.GetCustomAttribute(mInfo, _
GetType(ObsoleteAttribute))
If Not attr Is Nothing And TypeOf attr Is ObsoleteAttribute Then
Dim obsAttr As ObsoleteAttribute = _
CType(attr, ObsoleteAttribute)
Console.WriteLine("The message is: ""{0}""", obsAttr.Message)
Else
Console.WriteLine("The message could not be retrieved.")
End If
End If
End Sub
End Module
' Output:
' The Obsolete attribute is defined for method Method1 of class TestClass.
' The message is: "This method is obsolete. Use Method2() instead."
Remarks
The ancestors of element
are searched for custom attributes.
Note
Starting with the .NET Framework version 2.0, this method returns true
if a type, method, or constructor has security attributes stored in the new metadata format. Assemblies compiled with version 2.0 or later use the new format. Dynamic assemblies and assemblies compiled with earlier versions of the .NET Framework use the old XML format. See Emitting Declarative Security Attributes.
Applies to
IsDefined(Module, Type)
- Source:
- Attribute.CoreCLR.cs
- Source:
- Attribute.CoreCLR.cs
- Source:
- Attribute.CoreCLR.cs
Determines whether any custom attributes of a specified type are applied to a module. Parameters specify the module, and the type of the custom attribute to search for.
public:
static bool IsDefined(System::Reflection::Module ^ element, Type ^ attributeType);
public static bool IsDefined (System.Reflection.Module element, Type attributeType);
static member IsDefined : System.Reflection.Module * Type -> bool
Public Shared Function IsDefined (element As Module, attributeType As Type) As Boolean
Parameters
- attributeType
- Type
The type, or a base type, of the custom attribute to search for.
Returns
true
if a custom attribute of type attributeType
is applied to element
; otherwise, false
.
Exceptions
element
or attributeType
is null
.
attributeType
is not derived from Attribute.
Examples
The following code example illustrates the use of IsDefined, taking a Module as a parameter.
using namespace System;
using namespace System::Diagnostics;
// Add the Debuggable attribute to the module.
[module:Debuggable(true,false)];
namespace IsDef2CS
{
ref class DemoClass
{
public:
static void Main()
{
// Get the class type to access its metadata.
Type^ clsType = DemoClass::typeid;
// See if the Debuggable attribute is defined for this module.
bool isDef = Attribute::IsDefined( clsType->Module, DebuggableAttribute::typeid );
// Display the result.
Console::WriteLine( "The Debuggable attribute {0} "
"defined for Module {1}.", isDef ? (String^)"is" : "is not", clsType->Module->Name );
// If the attribute is defined, display the JIT settings.
if ( isDef )
{
// Retrieve the attribute itself.
DebuggableAttribute^ dbgAttr = dynamic_cast<DebuggableAttribute^>(Attribute::GetCustomAttribute( clsType->Module, DebuggableAttribute::typeid ));
if ( dbgAttr != nullptr )
{
Console::WriteLine( "JITTrackingEnabled is {0}.", dbgAttr->IsJITTrackingEnabled );
Console::WriteLine( "JITOptimizerDisabled is {0}.", dbgAttr->IsJITOptimizerDisabled );
}
else
Console::WriteLine( "The Debuggable attribute "
"could not be retrieved." );
}
}
};
}
/*
* Output:
* The Debuggable attribute is defined for Module IsDef2CS.exe.
* JITTrackingEnabled is True.
* JITOptimizerDisabled is False.
*/
using System;
using System.Diagnostics;
// Add the Debuggable attribute to the module.
[module:Debuggable(true, false)]
namespace IsDef2CS
{
public class DemoClass
{
static void Main(string[] args)
{
// Get the class type to access its metadata.
Type clsType = typeof(DemoClass);
// See if the Debuggable attribute is defined for this module.
bool isDef = Attribute.IsDefined(clsType.Module,
typeof(DebuggableAttribute));
// Display the result.
Console.WriteLine("The Debuggable attribute {0} " +
"defined for Module {1}.",
isDef ? "is" : "is not",
clsType.Module.Name);
// If the attribute is defined, display the JIT settings.
if (isDef)
{
// Retrieve the attribute itself.
DebuggableAttribute dbgAttr = (DebuggableAttribute)
Attribute.GetCustomAttribute(clsType.Module,
typeof(DebuggableAttribute));
if (dbgAttr != null)
{
Console.WriteLine("JITTrackingEnabled is {0}.",
dbgAttr.IsJITTrackingEnabled);
Console.WriteLine("JITOptimizerDisabled is {0}.",
dbgAttr.IsJITOptimizerDisabled);
}
else
Console.WriteLine("The Debuggable attribute " +
"could not be retrieved.");
}
}
}
}
/*
* Output:
* The Debuggable attribute is defined for Module IsDef2CS.exe.
* JITTrackingEnabled is True.
* JITOptimizerDisabled is False.
*/
open System
open System.Diagnostics
// Add the Debuggable attribute to the module.
[<``module``: Debuggable(true, false)>]
do ()
type DemoClass = class end
// Get the class type to access its metadata.
let clsType = typeof<DemoClass>
// See if the Debuggable attribute is defined for this module.
let isDef = Attribute.IsDefined(clsType.Module, typeof<DebuggableAttribute>)
// Display the result.
printfn $"""The Debuggable attribute {if isDef then "is" else "is not"} defined for Module {clsType.Module.Name}."""
// If the attribute is defined, display the JIT settings.
if isDef then
// Retrieve the attribute itself.
let dbgAttr =
Attribute.GetCustomAttribute(clsType.Module, typeof<DebuggableAttribute>)
:?> DebuggableAttribute
if dbgAttr <> null then
printfn $"JITTrackingEnabled is {dbgAttr.IsJITTrackingEnabled}."
printfn $"JITOptimizerDisabled is {dbgAttr.IsJITOptimizerDisabled}."
else
printfn "The Debuggable attribute could not be retrieved."
// Output:
// The Debuggable attribute is defined for Module IsDef2CS.exe.
// JITTrackingEnabled is True.
// JITOptimizerDisabled is False.
Imports System.Reflection
Imports System.Diagnostics
' Add the Debuggable attribute to the module.
<Module: Debuggable(True, False)>
Module DemoModule
Sub Main()
' Get the module type information to access its metadata.
Dim modType As Type = GetType(DemoModule)
' See if the Debuggable attribute is defined.
Dim isDef As Boolean = Attribute.IsDefined(modType.Module, _
GetType(DebuggableAttribute))
Dim strDef As String
If isDef = True Then
strDef = "is"
Else
strDef = "is not"
End If
' Display the result
Console.WriteLine("The debuggable attribute {0} defined for " & _
"module {1}.", strDef, modType.Name)
' If the attribute is defined, display the JIT settings.
If isDef = True Then
' Retrieve the attribute itself.
Dim attr As Attribute = _
Attribute.GetCustomAttribute(modType.Module, _
GetType(DebuggableAttribute))
If Not attr Is Nothing And TypeOf attr Is DebuggableAttribute Then
Dim dbgAttr As DebuggableAttribute = _
CType(attr, DebuggableAttribute)
Console.WriteLine("JITTrackingEnabled is {0}.", _
dbgAttr.IsJITTrackingEnabled.ToString())
Console.WriteLine("JITOptimizerDisabled is {0}.", _
dbgAttr.IsJITOptimizerDisabled.ToString())
Else
Console.WriteLine("The Debuggable attribute could " & _
"not be retrieved.")
End If
End If
End Sub
End Module
' Output:
' The debuggable attribute is defined for module DemoModule.
' JITTrackingEnabled is True.
' JITOptimizerDisabled is False.
Remarks
The ancestors of element
are not searched for custom attributes.
Applies to
IsDefined(Assembly, Type)
- Source:
- Attribute.CoreCLR.cs
- Source:
- Attribute.CoreCLR.cs
- Source:
- Attribute.CoreCLR.cs
Determines whether any custom attributes are applied to an assembly. Parameters specify the assembly, and the type of the custom attribute to search for.
public:
static bool IsDefined(System::Reflection::Assembly ^ element, Type ^ attributeType);
public static bool IsDefined (System.Reflection.Assembly element, Type attributeType);
static member IsDefined : System.Reflection.Assembly * Type -> bool
Public Shared Function IsDefined (element As Assembly, attributeType As Type) As Boolean
Parameters
- element
- Assembly
An object derived from the Assembly class that describes a reusable collection of modules.
- attributeType
- Type
The type, or a base type, of the custom attribute to search for.
Returns
true
if a custom attribute of type attributeType
is applied to element
; otherwise, false
.
Exceptions
element
or attributeType
is null
.
attributeType
is not derived from Attribute.
Examples
The following code example illustrates the use of IsDefined, taking an Assembly as a parameter.
using namespace System;
using namespace System::Reflection;
// Add an AssemblyDescription attribute
[assembly:AssemblyDescription("A sample description")];
namespace IsDef1CS
{
ref class DemoClass
{
public:
static void Main()
{
// Get the class type to access its metadata.
Type^ clsType = DemoClass::typeid;
// Get the assembly object.
Assembly^ assy = clsType->Assembly;
// Store the assembly's name.
String^ assyName = assy->GetName()->Name;
//Type assyType = assy.GetType();
// See if the Assembly Description is defined.
bool isdef = Attribute::IsDefined( assy, AssemblyDescriptionAttribute::typeid );
if ( isdef )
{
// Affirm that the attribute is defined.
Console::WriteLine( "The AssemblyDescription attribute "
"is defined for assembly {0}.", assyName );
// Get the description attribute itself.
AssemblyDescriptionAttribute^ adAttr = dynamic_cast<AssemblyDescriptionAttribute^>(Attribute::GetCustomAttribute( assy, AssemblyDescriptionAttribute::typeid ));
// Display the description.
if ( adAttr != nullptr )
Console::WriteLine( "The description is \"{0}\".", adAttr->Description );
else
Console::WriteLine( "The description could not "
"be retrieved." );
}
else
Console::WriteLine( "The AssemblyDescription attribute is not "
"defined for assembly {0}.", assyName );
}
};
}
/*
* Output:
* The AssemblyDescription attributeis defined for assembly IsDef1CS.
* The description is "A sample description".
*/
using System;
using System.Reflection;
// Add an AssemblyDescription attribute
[assembly: AssemblyDescription("A sample description")]
namespace IsDef1CS
{
public class DemoClass
{
static void Main(string[] args)
{
// Get the class type to access its metadata.
Type clsType = typeof(DemoClass);
// Get the assembly object.
Assembly assy = clsType.Assembly;
// Store the assembly's name.
String assyName = assy.GetName().Name;
// See if the Assembly Description is defined.
bool isdef = Attribute.IsDefined(assy,
typeof(AssemblyDescriptionAttribute));
if (isdef)
{
// Affirm that the attribute is defined.
Console.WriteLine("The AssemblyDescription attribute " +
"is defined for assembly {0}.", assyName);
// Get the description attribute itself.
AssemblyDescriptionAttribute adAttr =
(AssemblyDescriptionAttribute)Attribute.GetCustomAttribute(
assy, typeof(AssemblyDescriptionAttribute));
// Display the description.
if (adAttr != null)
Console.WriteLine("The description is \"{0}\".",
adAttr.Description);
else
Console.WriteLine("The description could not " +
"be retrieved.");
}
else
Console.WriteLine("The AssemblyDescription attribute is not " +
"defined for assembly {0}.", assyName);
}
}
}
/*
* Output:
* The AssemblyDescription attribute is defined for assembly IsDef1CS.
* The description is "A sample description".
*/
open System
open System.Reflection
// Add an AssemblyDescription attribute
[<assembly: AssemblyDescription "A sample description">]
do ()
type DemoClass = class end
// Get the class type to access its metadata.
let clsType = typeof<DemoClass>
// Get the assembly object.
let assembly = clsType.Assembly;
// Store the assembly's name.
let assemblyName = assembly.GetName().Name
// See if the Assembly Description is defined.
let isdef =
Attribute.IsDefined(assembly, typeof<AssemblyDescriptionAttribute>)
if isdef then
// Affirm that the attribute is defined.
printfn $"The AssemblyDescription attribute is defined for assembly {assemblyName}."
// Get the description attribute itself.
let adAttr =
Attribute.GetCustomAttribute(assembly, typeof<AssemblyDescriptionAttribute>)
:?> AssemblyDescriptionAttribute
// Display the description.
if adAttr <> null then
printfn $"The description is \"{adAttr.Description}\"."
else
printfn $"The description could not be retrieved."
else
printfn $"The AssemblyDescription attribute is not defined for assembly {assemblyName}."
// Output:
// The AssemblyDescription attribute is defined for assembly IsDef1FS.
// The description is "A sample description".
Imports System.Reflection
' Add an AssemblyDescription attribute.
<Assembly: AssemblyDescription("A sample description")>
Module DemoModule
Sub Main()
' Get the assembly for this module.
Dim assy As System.Reflection.Assembly = GetType(DemoModule).Assembly
' Store the assembly name.
Dim assyName As String = assy.GetName().Name
' See if the AssemblyDescription attribute is defined.
If Attribute.IsDefined(assy, GetType(AssemblyDescriptionAttribute)) _
Then
' Affirm that the attribute is defined. Assume the filename of
' this code example is "IsDef1VB".
Console.WriteLine("The AssemblyDescription attribute is " & _
"defined for assembly {0}.", assyName)
' Get the description attribute itself.
Dim attr As Attribute = Attribute.GetCustomAttribute( _
assy, GetType(AssemblyDescriptionAttribute))
' Display the description.
If Not attr Is Nothing And _
TypeOf attr Is AssemblyDescriptionAttribute Then
Dim adAttr As AssemblyDescriptionAttribute = _
CType(attr, AssemblyDescriptionAttribute)
Console.WriteLine("The description is " & _
Chr(34) & "{0}" & Chr(34) & ".", adAttr.Description)
Else
Console.WriteLine("The description could not be retrieved.")
End If
Else
Console.WriteLine("The AssemblyDescription attribute is not " & _
"defined for assembly {0}.", assyName)
End If
End Sub
End Module
' Output:
' The AssemblyDescription attribute is defined for assembly IsDef1VB.
' The description is "A sample description".
Remarks
Note
Starting with the .NET Framework version 2.0, this method returns true
if the assembly has security attributes stored in the new metadata format. Assemblies compiled with version 2.0 or later use the new format. Dynamic assemblies and assemblies compiled with earlier versions of the .NET Framework use the old XML format. See Emitting Declarative Security Attributes.
Applies to
IsDefined(ParameterInfo, Type)
- Source:
- Attribute.CoreCLR.cs
- Source:
- Attribute.CoreCLR.cs
- Source:
- Attribute.CoreCLR.cs
Determines whether any custom attributes are applied to a method parameter. Parameters specify the method parameter, and the type of the custom attribute to search for.
public:
static bool IsDefined(System::Reflection::ParameterInfo ^ element, Type ^ attributeType);
public static bool IsDefined (System.Reflection.ParameterInfo element, Type attributeType);
static member IsDefined : System.Reflection.ParameterInfo * Type -> bool
Public Shared Function IsDefined (element As ParameterInfo, attributeType As Type) As Boolean
Parameters
- element
- ParameterInfo
An object derived from the ParameterInfo class that describes a parameter of a member of a class.
- attributeType
- Type
The type, or a base type, of the custom attribute to search for.
Returns
true
if a custom attribute of type attributeType
is applied to element
; otherwise, false
.
Exceptions
element
or attributeType
is null
.
attributeType
is not derived from Attribute.
Examples
The following code example illustrates the use of IsDefined, taking a ParameterInfo as a parameter.
using namespace System;
using namespace System::Reflection;
namespace IsDef5CS
{
public ref class TestClass
{
public:
// Assign a ParamArray attribute to the parameter using the keyword.
void Method1(... array<String^>^args ){}
};
ref class DemoClass
{
public:
static void Main()
{
// Get the class type to access its metadata.
Type^ clsType = TestClass::typeid;
// Get the MethodInfo object for Method1.
MethodInfo^ mInfo = clsType->GetMethod( "Method1" );
// Get the ParameterInfo array for the method parameters.
array<ParameterInfo^>^pInfo = mInfo->GetParameters();
if ( pInfo != nullptr )
{
// See if the ParamArray attribute is defined.
bool isDef = Attribute::IsDefined( pInfo[ 0 ], ParamArrayAttribute::typeid );
// Display the result.
Console::WriteLine( "The ParamArray attribute {0} defined for "
"parameter {1} of method {2}.", isDef ? (String^)"is" : "is not", pInfo[ 0 ]->Name, mInfo->Name );
}
else
Console::WriteLine( "The parameters information could "
"not be retrieved for method {0}.", mInfo->Name );
}
};
}
/*
* Output:
* The ParamArray attribute is defined for parameter args of method Method1.
*/
using System;
using System.Reflection;
namespace IsDef5CS
{
public class TestClass
{
// Assign a ParamArray attribute to the parameter using the keyword.
public void Method1(params String[] args)
{}
}
public class DemoClass
{
static void Main(string[] args)
{
// Get the class type to access its metadata.
Type clsType = typeof(TestClass);
// Get the MethodInfo object for Method1.
MethodInfo mInfo = clsType.GetMethod("Method1");
// Get the ParameterInfo array for the method parameters.
ParameterInfo[] pInfo = mInfo.GetParameters();
if (pInfo != null)
{
// See if the ParamArray attribute is defined.
bool isDef = Attribute.IsDefined(pInfo[0],
typeof(ParamArrayAttribute));
// Display the result.
Console.WriteLine("The ParamArray attribute {0} defined for " +
"parameter {1} of method {2}.",
isDef ? "is" : "is not",
pInfo[0].Name,
mInfo.Name);
}
else
Console.WriteLine("The parameters information could " +
"not be retrieved for method {0}.", mInfo.Name);
}
}
}
/*
* Output:
* The ParamArray attribute is defined for parameter args of method Method1.
*/
open System;
type TestClass() =
// Assign a ParamArray attribute to the parameter.
member _.Method1([<ParamArray>] args: string[]) = ()
// Get the class type to access its metadata.
let clsType = typeof<TestClass>
// Get the MethodInfo object for Method1.
let mInfo = clsType.GetMethod "Method1"
// Get the ParameterInfo array for the method parameters.
let pInfo = mInfo.GetParameters()
if pInfo <> null then
// See if the ParamArray attribute is defined.
let isDef = Attribute.IsDefined(pInfo[0], typeof<ParamArrayAttribute>)
// Display the result.
printfn $"""The ParamArray attribute {if isDef then "is" else "is not"} defined for parameter {pInfo[0].Name} of method {mInfo.Name}."""
else
printfn $"The parameters information could not be retrieved for method {mInfo.Name}."
// Output:
// The ParamArray attribute is defined for parameter args of method Method1.
Imports System.Reflection
Module DemoModule
Public Class TestClass
' Assign a ParamArray attribute to the parameter using the keyword.
Public Sub Method1(ByVal ParamArray args As String())
End Sub
End Class
Sub Main()
' Get the class type to access its metadata.
Dim clsType As Type = GetType(TestClass)
' Get the MethodInfo object for Method1.
Dim mInfo As MethodInfo = clsType.GetMethod("Method1")
' Get the ParameterInfo array for the method parameters.
Dim pInfo() As ParameterInfo = mInfo.GetParameters()
If Not pInfo(0) Is Nothing Then
' See if the ParamArray attribute is defined.
Dim isDef As Boolean = Attribute.IsDefined(pInfo(0), _
GetType(ParamArrayAttribute))
Dim strDef As String
If isDef = True Then
strDef = "is"
Else
strDef = "is not"
End If
' Display the result.
Console.WriteLine("The ParamArray attribute {0} defined " & _
"for parameter {1} of method {2}.", _
strDef, pInfo(0).Name, mInfo.Name)
Else
Console.WriteLine("Could not retrieve parameter information " & _
"for method {0}.", mInfo.Name)
End If
End Sub
End Module
' Output:
' The ParamArray attribute is defined for parameter args of method Method1.
Remarks
The ancestors of element
are searched for custom attributes.