MemberInfo.GetCustomAttributes Method
Definition
Important
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When overridden in a derived class, returns custom attributes applied to this member.
Overloads
| GetCustomAttributes(Boolean) |
When overridden in a derived class, returns an array of all custom attributes applied to this member. |
| GetCustomAttributes(Type, Boolean) |
When overridden in a derived class, returns an array of custom attributes applied to this member and identified by Type. |
GetCustomAttributes(Boolean)
- Source:
- MemberInfo.cs
- Source:
- MemberInfo.cs
- Source:
- MemberInfo.cs
When overridden in a derived class, returns an array of all custom attributes applied to this member.
public:
abstract cli::array <System::Object ^> ^ GetCustomAttributes(bool inherit);public abstract object[] GetCustomAttributes (bool inherit);abstract member GetCustomAttributes : bool -> obj[]Public MustOverride Function GetCustomAttributes (inherit As Boolean) As Object()Parameters
- inherit
- Boolean
true to search this member's inheritance chain to find the attributes; otherwise, false. This parameter is ignored for properties and events.
Returns
An array that contains all the custom attributes applied to this member, or an array with zero elements if no attributes are defined.
Implements
Exceptions
This member belongs to a type that is loaded into the reflection-only context. See How to: Load Assemblies into the Reflection-Only Context.
A custom attribute type could not be loaded.
Examples
The following example defines a custom attribute and associates the attribute with MyClass.MyMethod, retrieves the attribute at run time, and displays the result.
using namespace System;
using namespace System::Reflection;
// Define a custom attribute with one named parameter.
[AttributeUsage(AttributeTargets::All)]
public ref class MyAttribute: public Attribute
{
private:
String^ myName;
public:
MyAttribute( String^ name )
{
myName = name;
}
property String^ Name
{
String^ get()
{
return myName;
}
}
};
// Define a class that has the custom attribute associated with one of its members.
public ref class MyClass1
{
public:
[MyAttribute("This is an example attribute.")]
void MyMethod( int i )
{
return;
}
};
int main()
{
try
{
// Get the type of MyClass1.
Type^ myType = MyClass1::typeid;
// Get the members associated with MyClass1.
array<MemberInfo^>^myMembers = myType->GetMembers();
// Display the attributes for each of the members of MyClass1.
for ( int i = 0; i < myMembers->Length; i++ )
{
array<Object^>^myAttributes = myMembers[ i ]->GetCustomAttributes( true );
if ( myAttributes->Length > 0 )
{
Console::WriteLine( "\nThe attributes for the member {0} are: \n", myMembers[ i ] );
for ( int j = 0; j < myAttributes->Length; j++ )
Console::WriteLine( "The type of the attribute is {0}.", myAttributes[ j ] );
}
}
}
catch ( Exception^ e )
{
Console::WriteLine( "An exception occurred: {0}", e->Message );
}
}
using System;
using System.Reflection;
// Define a custom attribute with one named parameter.
[AttributeUsage(AttributeTargets.All)]
public class MyAttribute : Attribute
{
private string myName;
public MyAttribute(string name)
{
myName = name;
}
public string Name
{
get
{
return myName;
}
}
}
// Define a class that has the custom attribute associated with one of its members.
public class MyClass1
{
[MyAttribute("This is an example attribute.")]
public void MyMethod(int i)
{
return;
}
}
public class MemberInfo_GetCustomAttributes
{
public static void Main()
{
try
{
// Get the type of MyClass1.
Type myType = typeof(MyClass1);
// Get the members associated with MyClass1.
MemberInfo[] myMembers = myType.GetMembers();
// Display the attributes for each of the members of MyClass1.
for(int i = 0; i < myMembers.Length; i++)
{
Object[] myAttributes = myMembers[i].GetCustomAttributes(true);
if(myAttributes.Length > 0)
{
Console.WriteLine("\nThe attributes for the member {0} are: \n", myMembers[i]);
for(int j = 0; j < myAttributes.Length; j++)
Console.WriteLine("The type of the attribute is {0}.", myAttributes[j]);
}
}
}
catch(Exception e)
{
Console.WriteLine("An exception occurred: {0}", e.Message);
}
}
}
Imports System.Reflection
' Define a custom attribute with one named parameter.
<AttributeUsage(AttributeTargets.All)> Public Class MyAttribute
Inherits Attribute
Private myName As String
Public Sub New(ByVal name As String)
myName = name
End Sub
Public ReadOnly Property Name() As String
Get
Return myName
End Get
End Property
End Class
' Define a class that has the custom attribute associated with one of its members.
Public Class MyClass1
<MyAttribute("This is an example attribute.")> Public Sub MyMethod(ByVal i As Integer)
Return
End Sub
End Class
Public Class MemberInfo_GetCustomAttributes
Public Shared Sub Main()
Try
' Get the type of MyClass1.
Dim myType As Type = GetType(MyClass1)
' Get the members associated with MyClass1.
Dim myMembers As MemberInfo() = myType.GetMembers()
' Display the attributes for each of the members of MyClass1.
Dim i As Integer
For i = 0 To myMembers.Length - 1
Dim myAttributes As [Object]() = myMembers(i).GetCustomAttributes(False)
If myAttributes.Length > 0 Then
Console.WriteLine("The attributes for the member {0} are: ", myMembers(i))
Dim j As Integer
For j = 0 To myAttributes.Length - 1
Console.WriteLine("The type of the attribute is: {0}", myAttributes(j))
Next j
End If
Next i
Catch e As Exception
Console.WriteLine("An exception occurred: {0}.", e.Message)
End Try
End Sub
End Class
Remarks
This method ignores the inherit parameter for properties and events. To search the inheritance chain for attributes on properties and events, use the appropriate overloads of the Attribute.GetCustomAttributes method.
Note
In the .NET Framework version 2.0, this method returns security attributes on methods, constructors, and types if they are stored in the new metadata format. Assemblies compiled with version 2.0 use this format. Dynamic assemblies and assemblies compiled with earlier versions of the .NET Framework use the old XML format. See Emitting Declarative Security Attributes.
See also
Applies to
GetCustomAttributes(Type, Boolean)
- Source:
- MemberInfo.cs
- Source:
- MemberInfo.cs
- Source:
- MemberInfo.cs
When overridden in a derived class, returns an array of custom attributes applied to this member and identified by Type.
public:
abstract cli::array <System::Object ^> ^ GetCustomAttributes(Type ^ attributeType, bool inherit);public abstract object[] GetCustomAttributes (Type attributeType, bool inherit);abstract member GetCustomAttributes : Type * bool -> obj[]Public MustOverride Function GetCustomAttributes (attributeType As Type, inherit As Boolean) As Object()Parameters
- attributeType
- Type
The type of attribute to search for. Only attributes that are assignable to this type are returned.
- inherit
- Boolean
true to search this member's inheritance chain to find the attributes; otherwise, false. This parameter is ignored for properties and events.
Returns
An array of custom attributes applied to this member, or an array with zero elements if no attributes assignable to attributeType have been applied.
Implements
Exceptions
A custom attribute type cannot be loaded.
If attributeType is null.
This member belongs to a type that is loaded into the reflection-only context. See How to: Load Assemblies into the Reflection-Only Context.
Examples
The following example defines a class named BaseClass that has two non-inherited members: a thread static field named total and a non-CLS-compliant method named MethodA. A class named DerivedClass inherits from BaseClass and overrides its MethodA method. Note that no attributes are applied to the members of DerivedClass. The example iterates the members of DerivedClass to determine whether the CLSCompliantAttribute or ThreadStaticAttribute attribute as been applied to them. Because inherit is true, the method searches the inheritance hierarchy of DerivedClass for the specified attribute. As the output from the example shows, the total field is decorated with the ThreadStaticAttribute attribute, and the MethodA method is decorated with the CLSCompliantAttribute attribute.
using System;
public class BaseClass
{
[ThreadStatic] public int total;
[CLSCompliant(false)] public virtual uint MethodA()
{
return (uint) 100;
}
}
public class DerivedClass : BaseClass
{
public override uint MethodA()
{
total++;
return 200;
}
}
public class Example
{
public static void Main()
{
Type t = typeof(DerivedClass);
Console.WriteLine("Members of {0}:", t.FullName);
foreach (var m in t.GetMembers())
{
bool hasAttribute = false;
Console.Write(" {0}: ", m.Name);
if (m.GetCustomAttributes(typeof(CLSCompliantAttribute), true).Length > 0) {
Console.Write("CLSCompliant");
hasAttribute = true;
}
if (m.GetCustomAttributes(typeof(ThreadStaticAttribute), true).Length > 0) {
Console.Write("ThreadStatic");
hasAttribute = true;
}
if (!hasAttribute)
Console.Write("No attributes");
Console.WriteLine();
}
}
}
// The example displays the following output:
// Members of DerivedClass:
// MethodA: CLSCompliant
// ToString: No attributes
// Equals: No attributes
// GetHashCode: No attributes
// typeof: No attributes
// .ctor: No attributes
// total: ThreadStatic
Public Class BaseClass
<ThreadStatic> Public total As Integer
<CLSCompliant(False)> Public Overridable Function MethodA() As UInt32
Return CUInt(100)
End Function
End Class
Public Class DerivedClass : Inherits BaseClass
Public Overrides Function MethodA() As UInt32
total += 1
Return 200
End Function
End Class
Module Example
Public Sub Main()
Dim t As Type = GetType(DerivedClass)
Console.WriteLine("Members of {0}:", t.FullName)
For Each m In t.GetMembers()
Dim hasAttribute As Boolean = False
Console.Write(" {0}: ", m.Name)
If m.GetCustomAttributes(GetType(CLSCompliantAttribute), True).Length > 0 Then
Console.Write("CLSCompliant")
hasAttribute = True
End If
If m.GetCustomAttributes(GetType(ThreadStaticAttribute), True).Length > 0 Then
Console.Write("ThreadStatic")
hasAttribute = True
End If
If Not hasAttribute Then
Console.Write("No attributes")
End If
Console.WriteLine()
Next
End Sub
End Module
' The example displays the following output:
' Members of DerivedClass:
' MethodA: CLSCompliant
' ToString: No attributes
' Equals: No attributes
' GetHashCode: No attributes
' GetType: No attributes
' .ctor: No attributes
' total: ThreadStatic
Remarks
This method ignores the inherit parameter for properties and events. To search the inheritance chain for attributes on properties and events, use the appropriate overloads of the Attribute.GetCustomAttributes method.
Note
In the .NET Framework version 2.0, this method returns security attributes on methods, constructors, and types if the attributes are stored in the new metadata format. Assemblies compiled with version 2.0 use this format. Dynamic assemblies and assemblies compiled with earlier versions of the .NET Framework use the old XML format. See Emitting Declarative Security Attributes.
