Attribute.Match メソッド
派生クラス内でオーバーライドされたときに、指定したオブジェクトとこのインスタンスが等しいかどうかを示す値を返します。 名前空間: System
アセンブリ: mscorlib (mscorlib.dll 内)
構文
パラメータ
戻り値
このインスタンスと obj が等しい場合は true。それ以外の場合は false。 解説
使用例
プラットフォーム
バージョン情報
参照
アセンブリ: mscorlib (mscorlib.dll 内)
構文Dim instance As Attribute Dim obj As Object Dim returnValue As Boolean returnValue = instance.Match(obj)
戻り値
このインスタンスと obj が等しい場合は true。それ以外の場合は false。
解説このメソッドは、Attribute が相互に等しいかどうかを判断します。既定の実装は Equals の場合と同じであり、値および参照比較を実行します。フラグやビット フィールドなど、単独で意味を持つコンポーネントで構成される属性値のサポートを実装するには、このメソッドをオーバーライドします。
たとえば、ある属性の値が、フラグのビット フィールドに分割されたバイナリ フィールドであるとします。この属性の 2 つのインスタンスにおいて、共通フラグが 1 つあり、その他のフラグはすべて異なるとします。Equals メソッドは、この 2 つのインスタンスに同じフラグが設定されているかどうかを判断できませんが、Match メソッドは判断できます。
使用例Attribute のコンテキストでの Match の使用方法を次のコード例に示します。
Imports System Imports System.Reflection Module DemoModule ' A custom attribute to allow 2 authors per method. <AttributeUsage(AttributeTargets.Method)> _ Public Class AuthorsAttribute Inherits Attribute Public Sub New(ByVal name1 As String, ByVal name2 As String) myAuthorName1 = name1 myAuthorName2 = name2 End Sub Protected myAuthorName1 As String Protected myAuthorName2 As String Public Property AuthorName1() As String Get Return myAuthorName1 End Get Set(ByVal Value As String) myAuthorName1 = AuthorName1 End Set End Property Public Property AuthorName2() As String Get Return myAuthorName2 End Get Set(ByVal Value As String) myAuthorName2 = AuthorName2 End Set End Property ' Use the hash code of the string objects and xor them together. Public Overrides Function GetHashCode() As Integer Return myAuthorName1.GetHashCode() Xor myAuthorName2.GetHashCode() End Function ' Determine if the object is a match to this one. Public Overrides Function Match(ByVal obj As Object) As Boolean ' Obviously a match. If obj Is Me Then Return True End If ' Obviously we're not nothing, so no. If obj Is Nothing Then Return False End If If TypeOf obj Is AuthorsAttribute Then ' Combine the hash codes and see if they're unchanged. Dim authObj As AuthorsAttribute = CType(obj, AuthorsAttribute) Dim firstHash As Integer = authObj.GetHashCode() And GetHashCode() If firstHash = GetHashCode() Then Return True Else Return False End If Else Return False End If End Function End Class ' Add some authors to methods of a class. Public Class TestClass1 <Authors("William Shakespeare", "Herman Melville")> _ Public Sub Method1() End Sub <Authors("Leo Tolstoy", "John Milton")> _ Public Sub Method2() End Sub End Class ' Add authors to a second class's methods. Public Class TestClass2 <Authors("William Shakespeare", "Herman Melville")> _ Public Sub Method1() End Sub <Authors("Leo Tolstoy", "John Milton")> _ Public Sub Method2() End Sub <Authors("Francis Bacon", "Miguel Cervantes")> _ Public Sub Method3() End Sub End Class Sub Main() ' Get the type for both classes to access their metadata. Dim clsType1 As Type = GetType(TestClass1) Dim clsType2 As Type = GetType(TestClass2) Dim mInfo1 As MethodInfo ' Iterate through each method of the first class. For Each mInfo1 In clsType1.GetMethods() ' Check each method for the Authors attribute. Dim attr1 As Attribute = Attribute.GetCustomAttribute(mInfo1, _ GetType(AuthorsAttribute)) If Not attr1 Is Nothing And TypeOf attr1 Is AuthorsAttribute Then Dim authAttr1 As AuthorsAttribute = _ CType(attr1, AuthorsAttribute) ' Display the authors. Console.WriteLine("Method {0} was authored by {1} and {2}.", _ mInfo1.Name, authAttr1.AuthorName1, _ authAttr1.AuthorName2) Dim mInfo2 As MethodInfo ' Iterate through each method of the second class. For Each mInfo2 In clsType2.GetMethods() ' Check each method for the Authors attribute. Dim attr2 As Attribute = Attribute.GetCustomAttribute( _ mInfo2, GetType(AuthorsAttribute)) If Not attr2 Is Nothing And _ TypeOf attr2 Is AuthorsAttribute Then Dim authAttr2 As AuthorsAttribute = _ CType(attr2, AuthorsAttribute) ' Compare with the authors in the first class. If authAttr2.Match(authAttr1) = True Then Console.WriteLine("Method {0} in class {1} was " + _ "also authored by the same team.", _ mInfo2.Name, clsType2.Name) End If End If Next Console.WriteLine("") End If Next End Sub End Module ' Output: ' Method Method1 was authored by William Shakespeare and Herman Melville. ' Method Method1 in class TestClass2 was also authored by the same team. ' ' Method Method2 was authored by Leo Tolstoy and John Milton. ' Method Method2 in class TestClass2 was also authored by the same team.
using System; using System.Reflection; namespace MatchCS { // A custom attribute to allow 2 authors per method. public class AuthorsAttribute : Attribute { public AuthorsAttribute(string name1, string name2) { authorName1 = name1; authorName2 = name2; } protected string authorName1; protected string authorName2; public string AuthorName1 { get { return authorName1; } set { authorName1 = AuthorName1; } } public string AuthorName2 { get { return authorName2; } set { authorName2 = AuthorName2; } } // Use the hash code of the string objects and xor them together. public override int GetHashCode() { return authorName1.GetHashCode() ^ authorName2.GetHashCode(); } // Determine if the object is a match to this one. public override bool Match(object obj) { // Obviously a match. if (obj == this) return true; // Obviously we're not null, so no. if (obj == null) return false; if (obj is AuthorsAttribute) // Combine the hash codes and see if they're unchanged. return (((AuthorsAttribute)obj).GetHashCode() & GetHashCode()) == GetHashCode(); else return false; } } // Add some authors to methods of a class. public class TestClass1 { [Authors("William Shakespeare", "Herman Melville")] public void Method1() {} [Authors("Leo Tolstoy", "John Milton")] public void Method2() {} } // Add authors to a second class's methods. public class TestClass2 { [Authors("William Shakespeare", "Herman Melville")] public void Method1() {} [Authors("Leo Tolstoy", "John Milton")] public void Method2() {} [Authors("William Shakespeare", "John Milton")] public void Method3() {} } class DemoClass { static void Main(string[] args) { // Get the type for both classes to access their metadata. Type clsType1 = typeof(TestClass1); Type clsType2 = typeof(TestClass2); // Iterate through each method of the first class. foreach(MethodInfo mInfo1 in clsType1.GetMethods()) { // Check each method for the Authors attribute. AuthorsAttribute authAttr1 = (AuthorsAttribute) Attribute.GetCustomAttribute(mInfo1, typeof(AuthorsAttribute)); if (authAttr1 != null) { // Display the authors. Console.WriteLine("Method {0} was authored by {1} " + "and {2}.", mInfo1.Name, authAttr1.AuthorName1, authAttr1.AuthorName2); // Iterate through each method of the second class. foreach(MethodInfo mInfo2 in clsType2.GetMethods()) { // Check each method for the Authors attribute. AuthorsAttribute authAttr2 = (AuthorsAttribute) Attribute.GetCustomAttribute(mInfo2, typeof(AuthorsAttribute)); // Compare with the authors in the first class. if (authAttr2 != null && authAttr2.Match(authAttr1)) Console.WriteLine("Method {0} in class {1} " + "was authored by the same team.", mInfo2.Name, clsType2.Name); } Console.WriteLine(""); } } } } } /* * Output: * Method Method1 was authored by William Shakespeare and Herman Melville. * Method Method1 in class TestClass2 was authored by the same team. * * Method Method2 was authored by Leo Tolstoy and John Milton. * Method Method2 in class TestClass2 was authored by the same team. */
using namespace System; using namespace System::Reflection; // A custom attribute to allow 2 authors per method. public ref class AuthorsAttribute: public Attribute { public: AuthorsAttribute( String^ name1, String^ name2 ) { authorName1 = name1; authorName2 = name2; } protected: String^ authorName1; String^ authorName2; public: property String^ AuthorName1 { String^ get() { return authorName1; } void set( String^ value ) { authorName1 = value; } } property String^ AuthorName2 { String^ get() { return authorName2; } void set( String^ value ) { authorName2 = value; } } // Use the hash code of the string objects and xor them together. virtual int GetHashCode() override { return authorName1->GetHashCode() ^ authorName2->GetHashCode(); } // Determine if the object is a match to this one. virtual bool Match( Object^ obj ) override { // Obviously a match. if ( obj == this ) return true; // Obviously we're not null, so no. if ( obj == nullptr ) return false; if ( dynamic_cast<AuthorsAttribute^>(obj) ) // Combine the hash codes and see if they're unchanged. return (dynamic_cast<AuthorsAttribute^>(obj)->GetHashCode() & GetHashCode()) == GetHashCode(); else return false; } }; // Add some authors to methods of a class. public ref class TestClass1 { public: [Authors("William Shakespeare","Herman Melville")] void Method1(){} [Authors("Leo Tolstoy","John Milton")] void Method2(){} }; // Add authors to a second class's methods. public ref class TestClass2 { public: [Authors("William Shakespeare","Herman Melville")] void Method1(){} [Authors("Leo Tolstoy","John Milton")] void Method2(){} [Authors("William Shakespeare","John Milton")] void Method3(){} }; int main() { // Get the type for both classes to access their metadata. Type^ clsType1 = TestClass1::typeid; Type^ clsType2 = TestClass2::typeid; // Iterate through each method of the first class. System::Collections::IEnumerator^ myEnum = clsType1->GetMethods()->GetEnumerator(); while ( myEnum->MoveNext() ) { MethodInfo^ mInfo1 = safe_cast<MethodInfo^>(myEnum->Current); // Check each method for the Authors attribute. AuthorsAttribute^ authAttr1 = dynamic_cast<AuthorsAttribute^>(Attribute::GetCustomAttribute( mInfo1, AuthorsAttribute::typeid )); if ( authAttr1 != nullptr ) { // Display the authors. Console::WriteLine( "Method {0} was authored by {1} and {2}.", mInfo1->Name, authAttr1->AuthorName1, authAttr1->AuthorName2 ); // Iterate through each method of the second class. System::Collections::IEnumerator^ myEnum1 = clsType2->GetMethods()->GetEnumerator(); while ( myEnum1->MoveNext() ) { MethodInfo^ mInfo2 = safe_cast<MethodInfo^>(myEnum1->Current); // Check each method for the Authors attribute. AuthorsAttribute^ authAttr2 = dynamic_cast<AuthorsAttribute^>(Attribute::GetCustomAttribute( mInfo2, AuthorsAttribute::typeid )); // Compare with the authors in the first class. if ( authAttr2 != nullptr && authAttr2->Match(authAttr1) ) Console::WriteLine( "Method {0} in class {1} was authored by the same team.", mInfo2->Name, clsType2->Name ); } Console::WriteLine(); } } } /* * Output: * Method Method1 was authored by William Shakespeare and Herman Melville. * Method Method1 in class TestClass2 was authored by the same team. * * Method Method2 was authored by Leo Tolstoy and John Milton. * Method Method2 in class TestClass2 was authored by the same team. */
package MatchJSL; import System.*; import System.Reflection.*; // A custom attribute to allow 2 authors per method. /** @attribute AttributeUsage(AttributeTargets.Method, AllowMultiple = true) */ public class AuthorsAttribute extends Attribute { public AuthorsAttribute(String name1, String name2) { authorName1 = name1; authorName2 = name2; } //AuthorsAttribute protected String authorName1; protected String authorName2; /** @property */ public String get_AuthorName1() { return authorName1; } //get_AuthorName1 /** @property */ public void set_AuthorName1(String value) { authorName1 = value; } //set_AuthorName1 /** @property */ public String get_AuthorName2() { return authorName2; } //get_AuthorName2 /** @property */ public void set_AuthorName2(String value) { authorName2 = value; } //set_AuthorName2 // Use the hash code of the string objects and xor them together. public int GetHashCode() { return authorName1.GetHashCode() ^ authorName2.GetHashCode(); } //GetHashCode // Determine if the object is a match to this one. public boolean Match(Object obj) { // Obviously a match. if (obj.Equals(this)) { return true; } // Obviously we're not null, so no. if (obj == null) { return false; } if (obj instanceof AuthorsAttribute) { // Combine the hash codes and see if they're unchanged. return (((AuthorsAttribute)obj).GetHashCode() & GetHashCode()) == GetHashCode(); } else { return false; } } //Match } //AuthorsAttribute // Add some authors to methods of a class. public class TestClass1 { /** @attribute Authors("William Shakespeare", "Herman Melville") */ public void Method1() { } //Method1 /** @attribute Authors("Leo Tolstoy", "John Milton") */ public void Method2() { } //Method2 } //TestClass1 // Add authors to a second class's methods. public class TestClass2 { /** @attribute Authors("William Shakespeare", "Herman Melville") */ public void Method1() { } //Method1 /** @attribute Authors("Leo Tolstoy", "John Milton") */ public void Method2() { } //Method2 /** @attribute Authors("William Shakespeare", "John Milton") */ public void Method3() { } //Method3 } //TestClass2 class DemoClass { public static void main(String[] args) { // Get the type for both classes to access their metadata. Type clsType1 = TestClass1.class.ToType(); Type clsType2 = TestClass2.class.ToType(); // Iterate through each method of the first class. for (int iCtr1 = 0; iCtr1 < clsType1.GetMethods().get_Length(); iCtr1++) { MethodInfo mInfo1 = (MethodInfo)clsType1.GetMethods().get_Item(iCtr1); // Check each method for the Authors attribute. AuthorsAttribute authAttr1 = (AuthorsAttribute)Attribute.GetCustomAttribute(mInfo1, AuthorsAttribute.class.ToType()); if (authAttr1 != null) { // Display the authors. Console.WriteLine("Method {0} was authored by {1} " + "and {2}.", mInfo1.get_Name(), authAttr1.get_AuthorName1(), authAttr1.get_AuthorName2()); // Iterate through each method of the second class. for (int iCtr2 = 0; iCtr2 < clsType1.GetMethods().get_Length(); iCtr2++) { MethodInfo mInfo2 = (MethodInfo)clsType1.GetMethods(). get_Item(iCtr2); // Check each method for the Authors attribute. AuthorsAttribute authAttr2 = (AuthorsAttribute)Attribute. GetCustomAttribute(mInfo2, AuthorsAttribute.class.ToType()); // Compare with the authors in the first class. if (authAttr2 != null && authAttr2.Match(authAttr1)) { Console.WriteLine("Method {0} in class {1} " + "was authored by the same team.", mInfo2.get_Name(), clsType2.get_Name()); } } Console.WriteLine(""); } } } //main } //DemoClass /* * Output: * Method Method1 was authored by William Shakespeare and Herman Melville. * Method Method1 in class TestClass2 was authored by the same team. * * Method Method2 was authored by Leo Tolstoy and John Milton. * Method Method2 in class TestClass2 was authored by the same team. */
import System; import System.Reflection; package MatchJS { // A custom attribute to allow 2 authors per method. AttributeUsage(AttributeTargets.Method) public class AuthorsAttribute extends Attribute { public function AuthorsAttribute(name1 : String, name2 : String) { authorName1 = name1; authorName2 = name2; } protected var authorName1 : String; protected var authorName2 : String ; public function get AuthorName1() : String { return authorName1; } public function set AuthorName1( value: String ) { authorName1 = value; } public function get AuthorName2() : String { return authorName2; } public function set AuthorName2(value : String){ authorName2 = AuthorName2; } // Use the hash code of the string objects and xor them together. public override function GetHashCode() : int { return authorName1.GetHashCode() ^ authorName2.GetHashCode(); } // Determine if the object is a match to this one. public override function Match(obj) : boolean { // Obviously a match. if (obj == this) return true; // Obviously we're not null, so no. if (obj == null) return false; if (obj instanceof AuthorsAttribute) // Combine the hash codes and see if they're unchanged. return (AuthorsAttribute(obj).GetHashCode() & GetHashCode()) == GetHashCode(); else return false; } } // Add some authors to methods of a class. public class TestClass1 { Authors("William Shakespeare", "Herman Melville") public function Method1() : void {} Authors("Leo Tolstoy", "John Milton") public function Method2() : void {} } // Add authors to a second class's methods. public class TestClass2 { Authors("William Shakespeare", "Herman Melville") public function Method1() : void {} Authors("Leo Tolstoy", "John Milton") public function Method2() : void {} Authors("William Shakespeare", "John Milton") public function Method3() : void {} } class DemoClass { static function Main() : void { // Get the type for both classes to access their metadata. var clsType1 : Type = TestClass1; var clsType2 : Type = TestClass2; // Iterate through each method of the first class. var methods1 : MethodInfo[] = clsType1.GetMethods(); for(var i : int in methods1) { var mInfo1 : MethodInfo = methods1[i]; // Check each method for the Authors attribute. var authAttr1 : AuthorsAttribute = AuthorsAttribute( Attribute.GetCustomAttribute(mInfo1, AuthorsAttribute)); if (authAttr1 != null) { // Display the authors. Console.WriteLine("Method {0} was authored by {1} " + "and {2}.", mInfo1.Name, authAttr1.AuthorName1, authAttr1.AuthorName2); // Iterate through each method of the second class. var methods2 : MethodInfo[] = clsType2.GetMethods() for( var j : int in methods2) { var mInfo2 : MethodInfo = methods2[j]; // Check each method for the Authors attribute. var authAttr2 : AuthorsAttribute = AuthorsAttribute( Attribute.GetCustomAttribute(mInfo2, AuthorsAttribute)); // Compare with the authors in the first class. if (authAttr2 != null && authAttr2.Match(authAttr1)) Console.WriteLine("Method {0} in class {1} " + "was authored by the same team.", mInfo2.Name, clsType2.Name); } Console.WriteLine(""); } } } } } MatchJS.DemoClass.Main(); /* * Output: * Method Method1 was authored by William Shakespeare and Herman Melville. * Method Method1 in class TestClass2 was authored by the same team. * * Method Method2 was authored by Leo Tolstoy and John Milton. * Method Method2 in class TestClass2 was authored by the same team. */
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バージョン情報参照- Attribute.Match メソッドのページへのリンク
