_MemberInfo.IsDefined メソッド
アセンブリ: mscorlib (mscorlib.dll 内)
構文
Dim instance As _MemberInfo Dim attributeType As Type Dim inherit As Boolean Dim returnValue As Boolean returnValue = instance.IsDefined(attributeType, inherit)
戻り値
このメンバに attributeType パラメータのインスタンスが 1 つ以上適用されている場合は true。それ以外の場合は false。
このメソッドは、アンマネージ コードからマネージ クラスにアクセスするためのメソッドであるため、マネージ コードからは呼び出さないでください。
IsDefined メソッドは、このメンバに attributeType パラメータのインスタンスが 1 つ以上適用されているかどうかを示します。
Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
開発プラットフォームの中には、.NET Framework によってサポートされていないバージョンがあります。サポートされているバージョンについては、「システム要件」を参照してください。
参照
MemberInfo.IsDefined メソッド
アセンブリ: mscorlib (mscorlib.dll 内)
構文
Public MustOverride Function IsDefined ( _ attributeType As Type, _ inherit As Boolean _ ) As Boolean
Dim instance As MemberInfo Dim attributeType As Type Dim inherit As Boolean Dim returnValue As Boolean returnValue = instance.IsDefined(attributeType, inherit)
戻り値
このメンバに attributeType のインスタンスが 1 つ以上適用されている場合は true。それ以外の場合は false。
指定した属性が指定したメンバに適用されているかどうかを調べる例を次に示します。
Imports System Imports System.Reflection Imports Microsoft.VisualBasic ' 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 'New Public ReadOnly Property Name() As String Get Return myName End Get End Property End Class 'MyAttribute ' 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 'MyMethod End Class 'MyClass1 Public Class MemberInfo_GetCustomAttributes_IsDefined 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 ' Display the attribute if it is of type MyAttribute. If myMembers(i).IsDefined(GetType(MyAttribute), False) Then Dim myAttributes As [Object]() = myMembers(i).GetCustomAttributes(GetType(MyAttribute), False) Console.WriteLine(ControlChars.Cr + "The attributes of type MyAttribute for the member {0} are: " + ControlChars.Cr, myMembers(i)) Dim j As Integer For j = 0 To myAttributes.Length - 1 ' Display the value associated with the attribute. Console.WriteLine("The value of the attribute is : ""{0}""", CType(myAttributes(j), MyAttribute).Name) Next j End If Next i Catch e As Exception Console.WriteLine("An exception occurred: {0}", e.Message) End Try End Sub 'Main End Class 'MemberInfo_GetCustomAttributes_IsDefined
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_IsDefined { 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++) { // Display the attribute if it is of type MyAttribute. if(myMembers[i].IsDefined(typeof(MyAttribute), false)) { Object[] myAttributes = myMembers[i].GetCustomAttributes(typeof(MyAttribute), false); Console.WriteLine("\nThe attributes of type MyAttribute for the member {0} are: \n", myMembers[i]); for(int j = 0; j < myAttributes.Length; j++) // Display the value associated with the attribute. Console.WriteLine("The value of the attribute is : \"{0}\"" , ((MyAttribute)myAttributes[j]).Name); } } } catch(Exception e) { Console.WriteLine("An exception occurred: {0}", e.Message); } } }
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 ){} }; 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++ ) { // Display the attribute if it is of type MyAttribute. if ( myMembers[ i ]->IsDefined( MyAttribute::typeid, false ) ) { array<Object^>^myAttributes = myMembers[ i ]->GetCustomAttributes( MyAttribute::typeid, false ); Console::WriteLine( "\nThe attributes of type MyAttribute for the member {0} are: \n", myMembers[ i ] ); for ( int j = 0; j < myAttributes->Length; j++ ) // Display the value associated with the attribute. Console::WriteLine( "The value of the attribute is : \"{0}\"" , (safe_cast<MyAttribute^>(myAttributes[ j ]))->Name ); } } } catch ( Exception^ e ) { Console::WriteLine( "An exception occurred: {0}", e->Message ); } }
import System.*; import System.Reflection.*; // Define a custom attribute with one named parameter. /** @attribute AttributeUsage(AttributeTargets.All) */ public class MyAttribute extends Attribute { private String myName; public MyAttribute(String name) { myName = name; } //MyAttribute /** @property */ public String get_Name() { return myName; } //get_Name } //MyAttribute // Define a class that has the custom attribute associated // with one of its members. public class MyClass1 { /** @attribute MyAttribute("This is an example attribute.") */ public void MyMethod(int i) { return; } //MyMethod } //MyClass1 public class MemberInfo_GetCustomAttributes_IsDefined { public static void main(String[] args) { try { // Get the type of MyClass1. Type myType = MyClass1.class.ToType(); // 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++) { // Display the attribute if it is of type MyAttribute. if (((MemberInfo)myMembers.get_Item(i)). IsDefined(MyAttribute.class.ToType(), false)) { Object myAttributes[] = ((MemberInfo)myMembers.get_Item(i)). GetCustomAttributes(MyAttribute.class.ToType(), false); Console.WriteLine("\nThe attributes of type MyAttribute for" + " the member {0} are: \n", myMembers.get_Item(i)); for (int j = 0; j < myAttributes.length; j++) { // Display the value associated with the attribute. Console.WriteLine("The value of the attribute is : \"" + "{0}\"", ((MyAttribute)myAttributes.get_Item(j)). get_Name()); } } } } catch (System.Exception e) { Console.WriteLine("An exception occurred: {0}", e.get_Message()); } } //main } //MemberInfo_GetCustomAttributes_IsDefined
Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
開発プラットフォームの中には、.NET Framework によってサポートされていないバージョンがあります。サポートされているバージョンについては、「システム要件」を参照してください。
参照
- _MemberInfo.IsDefined メソッドのページへのリンク