CodeRemoveEventStatement クラスとは何？わかりやすく解説 Weblio辞書

.NET Framework クラスライブラリリファレンス

索引トップ用語の索引ランキング

CodeRemoveEventStatement クラス

イベントハンドラの結び付けを解除するステートメントを表します。

名前空間: System.CodeDom
アセンブリ: System (system.dll 内)
構文

Visual Basic (宣言)

<SerializableAttribute> _
<ClassInterfaceAttribute(ClassInterfaceType.AutoDispatch)> _
<ComVisibleAttribute(True)> _
Public Class CodeRemoveEventStatement
    Inherits CodeStatement

Visual Basic (使用法)

Dim instance As CodeRemoveEventStatement

[SerializableAttribute] 
[ClassInterfaceAttribute(ClassInterfaceType.AutoDispatch)] 
[ComVisibleAttribute(true)] 
public class CodeRemoveEventStatement : CodeStatement

C++

[SerializableAttribute] 
[ClassInterfaceAttribute(ClassInterfaceType::AutoDispatch)] 
[ComVisibleAttribute(true)] 
public ref class CodeRemoveEventStatement :
 public CodeStatement

/** @attribute SerializableAttribute() */ 
/** @attribute ClassInterfaceAttribute(ClassInterfaceType.AutoDispatch) */ 
/** @attribute ComVisibleAttribute(true) */ 
public class CodeRemoveEventStatement extends
 CodeStatement

JScript

SerializableAttribute 
ClassInterfaceAttribute(ClassInterfaceType.AutoDispatch) 
ComVisibleAttribute(true) 
public class CodeRemoveEventStatement extends
 CodeStatement

解説

CodeRemoveEventStatement を使用して、イベントのイベントハンドラを削除するステートメントを表すことができます。

Event プロパティは、イベントハンドラが削除されるイベントを指定します。Listener プロパティは、削除するイベントハンドラを指定します。

使用例

CodeRemoveEventStatement を使用して、イベントからデリゲートを削除する例を次に示します。

Visual Basic

' Creates a delegate of type System.EventHandler pointing to a method
 named OnMouseEnter.
Dim mouseEnterDelegate As New
 CodeDelegateCreateExpression(New CodeTypeReference("System.EventHandler"),
 New CodeThisReferenceExpression(), "OnMouseEnter")
' Creates a remove event statement that removes the delegate from the
 TestEvent event.
Dim removeEvent1 As New
 CodeRemoveEventStatement(New CodeThisReferenceExpression(),
 "TestEvent", mouseEnterDelegate)

' A Visual Basic code generator produces the following source code for
 the preceeding example code:

'   RemoveHandler TestEvent, AddressOf Me.OnMouseEnter

// Creates a delegate of type System.EventHandler pointing to a method
 named OnMouseEnter.
CodeDelegateCreateExpression mouseEnterDelegate = new CodeDelegateCreateExpression(
 new CodeTypeReference("System.EventHandler"), new
 CodeThisReferenceExpression(), "OnMouseEnter" );
// Creates a remove event statement that removes the delegate from the
 TestEvent event.
CodeRemoveEventStatement removeEvent1 = new CodeRemoveEventStatement(
 new CodeThisReferenceExpression(), "TestEvent", mouseEnterDelegate
 );

// A C# code generator produces the following source code for the preceeding
 example code:

//     this.TestEvent -= new System.EventHandler(this.OnMouseEnter);

C++

// Creates a delegate of type System.EventHandler pointing to a method
 named OnMouseEnter.
CodeDelegateCreateExpression^ mouseEnterDelegate = gcnew CodeDelegateCreateExpression(
 gcnew CodeTypeReference( "System.EventHandler" ),gcnew CodeThisReferenceExpression,"OnMouseEnter"
 );

// Creates a remove event statement that removes the delegate from the
 TestEvent event.
CodeRemoveEventStatement^ removeEvent1 = gcnew CodeRemoveEventStatement( gcnew CodeThisReferenceExpression,"TestEvent",mouseEnterDelegate
 );

// A C# code generator produces the following source code for the preceeding
 example code:
//     this.TestEvent -= new System.EventHandler(this.OnMouseEnter);

// Creates a delegate of type System.EventHandler pointing
// to a method named OnMouseEnter.
CodeDelegateCreateExpression mouseEnterDelegate = new 
    CodeDelegateCreateExpression(new CodeTypeReference(
    "System.EventHandler"), new CodeThisReferenceExpression()
,
    "OnMouseEnter");
// Creates a remove event statement that removes the delegate 
// from the TestEvent event.
CodeRemoveEventStatement removeEvent1 = new 
    CodeRemoveEventStatement(new CodeThisReferenceExpression()
,
    "TestEvent", mouseEnterDelegate);
// A VJ# code generator produces the following source code for 
// the preceeding example code:
//     this.TestEvent -= new System.EventHandler(this.OnMouseEnter);