Attribute.GetCustomAttributes Method (Assembly, Type)

Retrieves an array of the custom attributes applied to an assembly. Parameters specify the assembly, and the type of the custom attribute to search for.

Namespace:  System
Assembly:  mscorlib (in mscorlib.dll)

Public Shared Function GetCustomAttributes ( _
	element As Assembly, _
	attributeType As Type _
) As Attribute()


Type: System.Reflection.Assembly

An object derived from the Assembly class that describes a reusable collection of modules.

Type: System.Type

The type, or a base type, of the custom attribute to search for.

Return Value

Type: System.Attribute()
An Attribute array that contains the custom attributes of type attributeType applied to element, or an empty array if no such custom attributes exist.


element or attributeType is Nothing.


attributeType is not derived from Attribute.


Starting with the .NET Framework version 2.0, this method returns security attributes if the attributes are 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.

The following code example demonstrates the use of GetCustomAttributes, taking an Assembly as a parameter.

Imports System
Imports System.Reflection
Imports Microsoft.VisualBasic

<Assembly: AssemblyTitle("CustAttrs1VB")> 
<Assembly: AssemblyDescription("GetCustomAttributes() Demo")> 
<Assembly: AssemblyCompany("Microsoft")> 

Module DemoModule

    Sub Main()
        ' Get the Assembly type to access its metadata. 
        Dim assy As Reflection.Assembly = GetType(DemoModule).Assembly
        Dim attr As Attribute

        ' Iterate through all the attributes for the assembly. 
        For Each attr In Attribute.GetCustomAttributes(assy)

            ' Check for the AssemblyTitle attribute. 
            If TypeOf attr Is AssemblyTitleAttribute Then 
                ' Convert the attribute to access its data. 
                Dim attrTitle As AssemblyTitleAttribute = _
                    CType(attr, AssemblyTitleAttribute)
                Console.WriteLine("Assembly title is ""{0}"".", _

            ' Check for the AssemblyDescription attribute. 
            ElseIf TypeOf attr Is AssemblyDescriptionAttribute Then 
                ' Convert the attribute to access its data. 
                Dim attrDesc As AssemblyDescriptionAttribute = _
                    CType(attr, AssemblyDescriptionAttribute)
                Console.WriteLine("Assembly description is ""{0}"".", _

            ' Check for the AssemblyCompany attribute. 
            ElseIf TypeOf attr Is AssemblyCompanyAttribute Then 
                ' Convert the attribute to access its data. 
                Dim attrComp As AssemblyCompanyAttribute = _
                    CType(attr, AssemblyCompanyAttribute)
                Console.WriteLine("Assembly company is {0}.", _
            End If 
    End Sub 
End Module 

' Output: 
' Assembly company is Microsoft. 
' Assembly description is "GetCustomAttributes() Demo". 
' Assembly title is "CustAttrs1VB".

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

Supported in: Windows Phone 8.1

Supported in: Windows Phone Silverlight 8.1

Supported in: Windows Phone Silverlight 8

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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