Attribute::GetCustomAttribute Method (Assembly, Type)
Retrieves a custom attribute applied to a specified assembly. Parameters specify the assembly and the type of the custom attribute to search for.
Assembly: mscorlib (in mscorlib.dll)
Parameters
- element
- Type: System.Reflection::Assembly
An object derived from the Assembly class that describes a reusable collection of modules.
- attributeType
- Type: System::Type
The type, or a base type, of the custom attribute to search for.
Return Value
Type: System::AttributeA reference to the single custom attribute of type attributeType that is applied to element, or nullptr if there is no such attribute.
| Exception | Condition |
|---|---|
| ArgumentNullException | element or attributeType is nullptr. |
| ArgumentException | attributeType is not derived from Attribute. |
| AmbiguousMatchException | More than one of the requested attributes was found. |
Use the GetCustomAttributes method if you expect more than one value to be returned, or AmbiguousMatchException will be thrown.
Note |
|---|
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 illustrates the use of the GetCustomAttribute method 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". */
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