ITypeDescriptorContext

.NET Framework クラス ライブラリ リファレンス

ITypeDescriptorContext インターフェイス

コンテナやプロパティ記述子などの、コンポーネントに関する文脈情報を提供します。

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

Visual Basic (宣言)

<ComVisibleAttribute(True)> _
Public Interface ITypeDescriptorContext
    Inherits IServiceProvider

Visual Basic (使用法)

Dim instance As ITypeDescriptorContext

C#

[ComVisibleAttribute(true)] 
public interface ITypeDescriptorContext : IServiceProvider

C++

[ComVisibleAttribute(true)] 
public interface class ITypeDescriptorContext
 : IServiceProvider

J#

/** @attribute ComVisibleAttribute(true) */ 
public interface ITypeDescriptorContext extends IServiceProvider

JScript

ComVisibleAttribute(true) 
public interface ITypeDescriptorContext extends
 IServiceProvider

解説

ITypeDescriptorContext インターフェイスは、コンポーネントに関する文脈情報を提供します。ITypeDescriptorContext は通常、デザイン時コンテナに関する情報を提供するためにデザイン時に使用されます。このインターフェイスは、通常、型変換で使用されます。詳細については、「TypeConverter」を参照してください。

メモ
型コンバータをデザインする場合は、このインターフェイスの存在に頼りきらないようにしてください。必要とされる特定のインターフェイス、プロパティ、またはサービスを使用できない場合、型コンバータは、例外をスローするのではなく null 参照 (Visual Basic では Nothing) を返す必要があります。しかし、このインターフェイスのプロパティは、いつでも null 参照 (Visual Basic では Nothing) を返す場合があるため、この点を考慮して対処する必要があります。

使用例

ITypeDescriptorContext インターフェイスを使用して型変換をサポートする方法を次のコード例に示します。

Visual Basic

Imports System
Imports System.ComponentModel
Imports System.ComponentModel.Design.Serialization
Imports System.Drawing
Imports System.Globalization
Imports System.Reflection
Namespace Microsoft.Samples.InstanceDescriptorSample

   '  This sample shows how to support code generation for a custom
 type 
   '  of object using a type converter and InstanceDescriptor objects.
   '
   '  To use this code, copy it to a file and add the file to a project.
  
   '  Then add a component to the project and declare a Triangle field
 and 
   '  a public property with accessors for the Triangle field on the
 component.
   '
   '  The Triangle property will be persisted using code generation.

   <TypeConverter(GetType(Triangle.TriangleConverter))>
 _
   Public Class Triangle
      ' Triangle members.
      Private P1 As Point
      Private P2 As Point
      Private P3 As Point

      Public Property Point1() As
 Point
         Get
            Return P1
         End Get
         Set(ByVal Value As
 Point)
            P1 = Value
         End Set
      End Property

      Public Property Point2() As
 Point
         Get
            Return P2
         End Get
         Set(ByVal Value As
 Point)
            P2 = Value
         End Set
      End Property

      Public Property Point3() As
 Point
         Get
            Return P3
         End Get
         Set(ByVal Value As
 Point)
            P3 = Value
         End Set
      End Property

      Public Sub New(ByVal
 point1 As Point, ByVal point2 As
 Point, ByVal point3 As Point)
         P1 = point1
         P2 = point2
         P3 = point3
      End Sub 'New

      ' A TypeConverter for the Triangle object.  Note that you can
 make it internal,
      '  private, or any scope you want and the designers will still
 be able to use
      '  it through the TypeDescriptor object.  This type converter
 provides the
      '  capability to convert to an InstanceDescriptor.  This object
 can be used by 
      '  the .NET Framework to generate source code that creates an
 instance of a 
      '  Triangle object.

      Friend Class TriangleConverter
         Inherits TypeConverter

         ' This method overrides CanConvertTo from TypeConverter.  This
 is called when someone
         '  wants to convert an instance of Triangle to another type.
  Here,
         '  only coversition to an InstanceDescriptor is supported.
         Public Overloads Overrides
 Function CanConvertTo(ByVal context As
 ITypeDescriptorContext, ByVal destinationType As Type) As Boolean
            If destinationType Is GetType(InstanceDescriptor)
 Then
               Return True
            End If

            ' Always call the base to see if it can perform the conversion.
            Return MyBase.CanConvertTo(context,
 destinationType)
         End Function

         ' This code performs the actual conversion from a Triangle
 to an InstanceDescriptor.
         Public Overloads Overrides
 Function ConvertTo(ByVal context As
 ITypeDescriptorContext, ByVal culture As CultureInfo, ByVal value As Object,
 ByVal destinationType As Type) As Object
            If destinationType Is GetType(InstanceDescriptor)
 Then
               Dim ci As ConstructorInfo =
 GetType(Triangle).GetConstructor(New Type()
 {GetType(Point), GetType(Point), GetType(Point)})
               Dim t As Triangle = CType(value,
 Triangle)
               Return New InstanceDescriptor(ci,
 New Object() {t.Point1, t.Point2, t.Point3})
            End If

            ' Always call base, even if you can't convert.
            Return MyBase.ConvertTo(context,
 culture, value, destinationType)
         End Function 
      End Class 
   End Class 

   Public Class TestComponent
      Inherits System.ComponentModel.Component
      Private myTriangleProp As Triangle

      Public Sub New()
         myTriangleProp = New Triangle(New
 Point(5, 5), _
                                    New Point(10, 10), New
 Point(1, 8))
      End Sub

      Public Property MyTriangle() As
 Triangle
         Get
            Return myTriangleProp
         End Get
         Set(ByVal Value As
 Triangle)
            myTriangleProp = Value
         End Set
      End Property

   End Class

End Namespace

C#

namespace Microsoft.Samples.InstanceDescriptorSample
{
    using System;
    using System.ComponentModel;
    using System.ComponentModel.Design.Serialization;
    using System.Drawing;
    using System.Globalization;
    using System.Reflection;

    //  This sample shows how to support code generation for a custom
 type 
    //  of object using a type converter and InstanceDescriptor objects.

    //  To use this code, copy it to a file and add the file to a project.
 
    //  Then add a component to the project and declare a Triangle field
 and 
    //  a public property with accessors for the Triangle field on the
 component.

    //  The Triangle property will be persisted using code generation.

    [TypeConverter(typeof(Triangle.TriangleConverter))]
    public class Triangle
    {
        // Triangle members.
        Point P1;
        Point P2;
        Point P3;

        public Point Point1 {
            get {
                return P1;
            }
            set {
                P1 = value;
            }
        }
        public Point Point2 {
            get 
            {
                return P2;
            }
            set 
            {
                P2 = value;
            }
        }
        public Point Point3 {
            get 
            {
                return P3;
            }
            set 
            {
                P3 = value;
            }
        }

        public Triangle(Point point1,Point point2,Point point3)
 {
            P1 = point1;
            P2 = point2;
            P3 = point3;
        }

        // A TypeConverter for the Triangle object.  Note that you can
 make it internal,
        //  private, or any scope you want and the designers will still
 be able to use
        //  it through the TypeDescriptor object.  This type converter
 provides the
        //  capability to convert to an InstanceDescriptor.  This object
 can be used by 
    //  the .NET Framework to generate source code that creates an instance
 of a 
    //  Triangle object.
        internal class TriangleConverter : TypeConverter
        {
            // This method overrides CanConvertTo from TypeConverter.
 This is called when someone
            //  wants to convert an instance of Triangle to another
 type.  Here,
            //  only conversion to an InstanceDescriptor is supported.
            public override bool CanConvertTo(ITypeDescriptorContext
 context, Type destinationType)
            {
                if (destinationType == typeof(InstanceDescriptor))
                {
                    return true;
                }

                // Always call the base to see if it can perform the
 conversion.
                return base.CanConvertTo(context,
 destinationType);
            }

            // This code performs the actual conversion from a Triangle
 to an InstanceDescriptor.
            public override object ConvertTo(ITypeDescriptorContext
 context, CultureInfo culture, object value, Type destinationType)
            {
                if (destinationType == typeof(InstanceDescriptor))
                {
                    ConstructorInfo ci = typeof(Triangle).GetConstructor(new
 Type[]{typeof(Point),
                                                    typeof(Point),typeof(Point)});
                    Triangle t = (Triangle) value;
                    return new InstanceDescriptor(ci,new
 object[]{t.Point1,t.Point2,t.Point3});
                }

                // Always call base, even if you can't convert.
                return base.ConvertTo(context,
 culture, value, destinationType);
            }
        }
    }

    public class TestComponent : System.ComponentModel.Component
 
    {
        Triangle myTriangle;

        public TestComponent() {
            myTriangle = new Triangle(
                new Point(5,5),
                new Point(10,10),
                new Point(1,8)
                );
        }

        public Triangle MyTriangle {
            get {
                return myTriangle;
            }
            set {
                myTriangle = value;
            }
        }
    }
}

C++

#using <system.dll>
#using <system.drawing.dll>

using namespace System;
using namespace System::ComponentModel;
using namespace System::ComponentModel::Design::Serialization;
using namespace System::Drawing;
using namespace System::Globalization;
using namespace System::Collections;
using namespace System::Reflection;

/*   This sample shows how to support code generation for a custom
 type of object 
         using a type converter and InstanceDescriptor objects.

         To use this code, copy it to a file and add the file
 to a project. Then add
         a component to the project and declare a Triangle field and a public
 property 
         with accessors for the Triangle field on the component.

         The Triangle property will be persisted using code generation.
    */
ref class TriangleConverter;

[TypeConverter(TriangleConverter::typeid)]
public ref class Triangle
{
private:

   // Triangle members
   Point P1;
   Point P2;
   Point P3;

public:

   property Point Point1 
   {
      Point get()
      {
         return P1;
      }

      void set( Point value )
      {
         P1 = value;
      }
   }

   property Point Point2 
   {
      Point get()
      {
         return P2;
      }

      void set( Point value )
      {
         P2 = value;
      }
   }

   property Point Point3 
   {
      Point get()
      {
         return P3;
      }

      void set( Point value )
      {
         P3 = value;
      }

   }
   Triangle( Point point1, Point point2, Point point3 )
   {
      P1 = point1;
      P2 = point2;
      P3 = point3;
   }


   /* A TypeConverter for the Triangle object.  Note that you
 can make it internal,
      private, or any scope you want and the designers will still
 be able to use
      it through the TypeDescriptor object.  This type converter provides the
      capability to convert to an InstanceDescriptor.  This object can be used by
 
      the .NET Framework to generate source code that creates an instance of a 
      Triangle object. */
   [System::Security::Permissions::PermissionSet(System::Security::
      Permissions::SecurityAction::Demand, Name = "FullTrust")]
   ref class TriangleConverter: public TypeConverter
   {
   public:

      /* This method overrides CanConvertTo from TypeConverter. This is called when
 someone
            wants to convert an instance of Triangle to another type.  Here,
            only conversion to an InstanceDescriptor is supported. */
      virtual bool CanConvertTo( ITypeDescriptorContext^ context,
 Type^ destinationType ) override
      {
         if ( destinationType == InstanceDescriptor::typeid )
         {
            return true;
         }

         
         // Always call the base to see if it can perform the conversion.
         return TypeConverter::CanConvertTo( context, destinationType
 );
      }

      /* This code performs the actual conversion from a Triangle to an InstanceDescriptor.
 */
      virtual Object^ ConvertTo( ITypeDescriptorContext^ context, CultureInfo^ culture,
 Object^ value, Type^ destinationType ) override
      {
         if ( destinationType == InstanceDescriptor::typeid )
         {
            array<Type^>^type1 = {Point::typeid,Point::typeid,Point::typeid};
            ConstructorInfo^ ci = Triangle::typeid->GetConstructor( type1 );
            Triangle^ t = safe_cast<Triangle^>(value);
            array<Object^>^obj1 = {t->Point1,t->Point2,t->Point3};
            return gcnew InstanceDescriptor( ci,safe_cast<ICollection^>(obj1)
 );
         }

         // Always call base, even if you can't convert.
         return TypeConverter::ConvertTo( context, culture, value,
 destinationType );
      }
   };
};

public ref class TestComponent: public
 System::ComponentModel::Component
{
private:
   Triangle^ myTriangle;

public:
   TestComponent()
   {
      myTriangle = gcnew Triangle( Point(5,5),Point(10,10),Point(1,8) );
   }

   property Triangle^ MyTriangle 
   {
      Triangle^ get()
      {
         return myTriangle;
      }

      void set( Triangle^ value )
      {
         myTriangle = value;
      }
   }
};

J#

package Microsoft.Samples.InstanceDescriptorSample; 

import System.*;
import System.ComponentModel.*;
import System.ComponentModel.Design.Serialization.*;
import System.Drawing.*;
import System.Globalization.*;
import System.Reflection.*;
//  This sample shows how to support code generation for a custom type
 
//  of object using a type converter and InstanceDescriptor objects.
//  To use this code, copy it to a file and add the file to a project.
 
//  Then add a component to the project and declare a Triangle field
 and 
//  a public property with accessors for the Triangle field on the component.
//  The Triangle property will be persisted using code generation.
/** @ attribute TypeConverter(Triangle.TriangleConverter .class.ToType())
 */
public class Triangle
{
    // Triangle members.
    private Point P1;
    private Point P2;
    private Point P3;

    /** @property 
     */
    public Point get_Point1()
    {
        return P1;
    } //get_Point1

    /** @property 
     */
    public void set_Point1(Point value)
    {
        P1 = value;
    } //set_Point1

    /** @property 
     */
    public Point get_Point2()
    {
        return P2;
    } //get_Point2

    /** @property 
     */
    public void set_Point2(Point value)
    {
        P2 = value;
    } //set_Point2

    /** @property 
     */
    public Point get_Point3()
    {
        return P3;
    } //get_Point3

    /** @property 
     */
    public void set_Point3(Point value)
    {
        P3 = value;
    } //set_Point3

    public Triangle(Point point1, Point point2, Point point3)
    {
        P1 = point1;
        P2 = point2;
        P3 = point3;
    } //Triangle

    // A TypeConverter for the Triangle object. Note that you can make
 it 
    //internal,private, or any scope you want and the designers will
 still
    //be able to use it through the TypeDescriptor object.  This type
 converter
    //provides the capability to convert to an InstanceDescriptor. 
 This object
    //can be used by the .NET Framework to generate source code that
 creates an
    //instance of a Triangle object.
    class TriangleConverter extends TypeConverter
    {
        // This method overrides CanConvertTo from TypeConverter.
        //This is called when someone wants to convert an instance of
 Triangle
        //to another type.  Here, only conversion to an InstanceDescriptor
 is
        //supported.
        public boolean CanConvertTo(ITypeDescriptorContext context
,
            Type destinationType)
        {
            if (destinationType.Equals(InstanceDescriptor.class.ToType()))
 {
                return true;
            }
            // Always call the base to see if it can perform the conversion.
            return super.CanConvertTo(context, destinationType);
        } //CanConvertTo

        // This code performs the actual conversion from a Triangle
 to an 
        //InstanceDescriptor.
        public Object ConvertTo(ITypeDescriptorContext context
,
            CultureInfo culture, Object value, Type destinationType)
        {
            if (destinationType.Equals(InstanceDescriptor.class.ToType()))
 {
                ConstructorInfo ci = Triangle.class.ToType().GetConstructor(
                    new Type[] { Point.class.ToType(),
 Point.class.ToType(),
                    Point.class.ToType() });
                Triangle t = ((Triangle)(value));
                return new InstanceDescriptor(ci,
 new Object[] { t.get_Point1(),
                    t.get_Point2(), t.get_Point3() });
            }
            // Always call base, even if you can't convert.
            return super.ConvertTo(context, culture, value, destinationType);
        } //ConvertTo
    } //TriangleConverter
} //Triangle

public class TestComponent extends System.ComponentModel.Component
{
    private Triangle myTriangle;

    public TestComponent()
    {
        myTriangle = new Triangle(new Point(5,
 5), new Point(10, 10),
            new Point(1, 8));
    } //TestComponent

    /** @property 
     */
    public Triangle get_MyTriangle()
    {
        return myTriangle;
    } //get_MyTriangle

    /** @property 
     */
    public void set_MyTriangle(Triangle value)
    {
        myTriangle = value;
    } //set_MyTriangle
} //TestComponent

プラットフォーム

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。

バージョン情報

.NET Framework
サポート対象 : 2.0、1.1、1.0

参照

関連項目
ITypeDescriptorContext メンバ
System.ComponentModel 名前空間
TypeDescriptor
TypeConverter

ITypeDescriptorContext プロパティ

パブリック プロパティ

	名前	説明
	Container	TypeDescriptor 要求を表すコンテナを取得します。
	Instance	この型記述子の要求に関連付けられているオブジェクトを取得します。
	PropertyDescriptor	特定のコンテキスト項目に関連付けられている PropertyDescriptor を取得します。

参照

関連項目

ITypeDescriptorContext インターフェイス
System.ComponentModel 名前空間
TypeDescriptor
TypeConverter

ITypeDescriptorContext メソッド

パブリック メソッド

	名前	説明
	OnComponentChanged	ComponentChanged イベントを発生させます。
	OnComponentChanging	ComponentChanging イベントを発生させます。

参照

関連項目

ITypeDescriptorContext インターフェイス
System.ComponentModel 名前空間
TypeDescriptor
TypeConverter

ITypeDescriptorContext メンバ

コンテナやプロパティ記述子などの、コンポーネントに関する文脈情報を提供します。

ITypeDescriptorContext データ型で公開されるメンバを以下の表に示します。

パブリック プロパティ

	名前	説明
	Container	TypeDescriptor 要求を表すコンテナを取得します。
	Instance	この型記述子の要求に関連付けられているオブジェクトを取得します。
	PropertyDescriptor	特定のコンテキスト項目に関連付けられている PropertyDescriptor を取得します。

パブリック メソッド

	名前	説明
	OnComponentChanged	ComponentChanged イベントを発生させます。
	OnComponentChanging	ComponentChanging イベントを発生させます。

参照

関連項目

ITypeDescriptorContext インターフェイス
System.ComponentModel 名前空間
TypeDescriptor
TypeConverter