CodeDirectionExpression 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

CodeDirectionExpression クラス

参照方向のインジケータと共にメソッド呼び出しのパラメータとして使用される式を表します。

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 CodeDirectionExpression
    Inherits CodeExpression

Visual Basic (使用法)

Dim instance As CodeDirectionExpression

[SerializableAttribute] 
[ClassInterfaceAttribute(ClassInterfaceType.AutoDispatch)] 
[ComVisibleAttribute(true)] 
public class CodeDirectionExpression : CodeExpression

C++

[SerializableAttribute] 
[ClassInterfaceAttribute(ClassInterfaceType::AutoDispatch)] 
[ComVisibleAttribute(true)] 
public ref class CodeDirectionExpression :
 public CodeExpression

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

JScript

SerializableAttribute 
ClassInterfaceAttribute(ClassInterfaceType.AutoDispatch) 
ComVisibleAttribute(true) 
public class CodeDirectionExpression extends
 CodeExpression

解説

CodeDirectionExpression は、メソッドに渡されるパラメータとパラメータの参照方向を表すことができます。

Expression プロパティは、参照方向で修飾する式を示します。Direction プロパティは、FieldDirection 列挙値のいずれかを使用して、パラメータの参照方向を示します。

使用例

CodeDirectionExpression を使用して、メソッドのパラメータとして渡す式にフィールド方向修飾子を指定する例を次に示します。

Visual Basic

' Declares a parameter passed by reference using a CodeDirectionExpression.
Dim param1 As New CodeDirectionExpression(FieldDirection.Ref,
 New CodeFieldReferenceExpression(New CodeThisReferenceExpression(),
 "TestParameter"))
' Invokes a method on this named TestMethod using the direction expression
 as a parameter.
Dim methodInvoke1 As New
 CodeMethodInvokeExpression(New CodeThisReferenceExpression(),
 "TestMethod", param1)

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

'      Me.TestMethod("TestParameter")

// Declares a parameter passed by reference using a CodeDirectionExpression.
CodeDirectionExpression param1 = new CodeDirectionExpression(FieldDirection.Ref,
 new CodeFieldReferenceExpression( new CodeThisReferenceExpression(),
 "TestParameter" ));
// Invokes a method on this named TestMethod using the direction expression
 as a parameter.
CodeMethodInvokeExpression methodInvoke1 = new CodeMethodInvokeExpression(new
 CodeThisReferenceExpression(), "TestMethod", param1 );

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

//        this.TestMethod(ref TestParameter);

C++

// Declares a parameter passed by reference using a CodeDirectionExpression.
array<CodeDirectionExpression^>^param1 = {gcnew CodeDirectionExpression( FieldDirection::Ref,gcnew
 CodeFieldReferenceExpression( gcnew CodeThisReferenceExpression,"TestParameter"
 ) )};

// Invokes a method on this named TestMethod using the direction expression
 as a parameter.
CodeMethodInvokeExpression^ methodInvoke1 = gcnew CodeMethodInvokeExpression( gcnew
 CodeThisReferenceExpression,"TestMethod",param1 );

// A C# code generator produces the following source code for the preceeding
 example code:
//        this.TestMethod(ref TestParameter);

// Declares a parameter passed by reference using a 
// CodeDirectionExpression.
CodeDirectionExpression param1 = new CodeDirectionExpression(
    FieldDirection.Ref, new CodeFieldReferenceExpression(new
 
    CodeThisReferenceExpression(), "TestParameter"));
// Invokes a method on this named TestMethod using the direction 
// expression as a parameter.
CodeMethodInvokeExpression methodInvoke1 = new 
    CodeMethodInvokeExpression(new CodeThisReferenceExpression()
,
    "TestMethod", new CodeExpression[] { (CodeExpression)param1
 });
// A VJ# code generator produces the following source code for the 
// preceeding example code:    
// this.TestMethod(ref TestParameter);