CheckedListBox.WndProc メソッドとは何？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

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CheckedListBox.WndProc メソッド

Windows メッセージを処理します。

名前空間: System.Windows.Forms
アセンブリ: System.Windows.Forms (system.windows.forms.dll 内)
構文

Visual Basic (宣言)

Protected Overrides Sub
 WndProc ( _
    ByRef m As Message _
)

Visual Basic (使用法)

Dim m As Message

Me.WndProc(m)

protected override void WndProc (
    ref Message m
)

C++

protected:
virtual void WndProc (
    Message% m
) override

protected void WndProc (
    /** @ref */ Message m
)

JScript

JScript では、値型の引数は参照渡しされません。

パラメータ

m: 処理対象の Windows Message。

使用例

WndProc メソッドをオーバーライドして、Message 構造体で示されるオペレーティングシステムメッセージを処理する方法を次のコード例に示します。この例の場合、WM_ACTIVEAPP オペレーティングシステムメッセージは、別のアプリケーションがどのタイミングでアクティブになったかを判定するために処理されます。使用できる Message.Msg、Message.LParam、および Message.WParam の値については、MSDN ライブラリ (http://msdn.microsoft.com/library/ja) にあるプラットフォーム SDKのリファレンスを参照してください。実際の定数値は、プラットフォーム SDK (コア SDK セクション) のダウンロードに含まれている Windows.h ヘッダーファイルの中にあります。これは MSDN ライブラリ (http://msdn.microsoft.com/library/ja) からも入手できます。

Visual Basic

Imports System
Imports System.Drawing
Imports System.Windows.Forms

Namespace csTempWindowsApplication1

    Public Class Form1
        Inherits System.Windows.Forms.Form

        ' Constant value was found in the "windows.h" header
 file.
        Private Const WM_ACTIVATEAPP As
 Integer = &H1C
        Private appActive As Boolean
 = True

        <STAThread()> _
        Shared Sub Main()
            Application.Run(New Form1())
        End Sub 'Main

        Public Sub New()
            MyBase.New()

            Me.Size = New System.Drawing.Size(300,
 300)
            Me.Text = "Form1"
            Me.Font = New System.Drawing.Font("Microsoft
 Sans Serif", 18.0!, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point,
 CType(0, Byte))
        End Sub

        Protected Overrides Sub
 OnPaint(ByVal e As PaintEventArgs)

            ' Paint a string in different styles depending on whether
 the
            ' application is active.
            If (appActive) Then
                e.Graphics.FillRectangle(SystemBrushes.ActiveCaption, 20, 20, 260,
 50)
                e.Graphics.DrawString("Application is active",
 Me.Font, SystemBrushes.ActiveCaptionText, 20, 20)
            Else
                e.Graphics.FillRectangle(SystemBrushes.InactiveCaption, 20, 20, 260,
 50)
                e.Graphics.DrawString("Application is Inactive",
 Me.Font, SystemBrushes.ActiveCaptionText, 20, 20)
            End If
        End Sub
    <System.Security.Permissions.PermissionSetAttribute(System.Security.Permissions.SecurityAction.Demand,
 Name:="FullTrust")> _
        Protected Overrides Sub
 WndProc(ByRef m As Message)
            ' Listen for operating system messages
            Select Case (m.Msg)
                ' The WM_ACTIVATEAPP message occurs when the application
                ' becomes the active application or becomes inactive.
            Case WM_ACTIVATEAPP

                    ' The WParam value identifies what is occurring.
                    appActive = (m.WParam.ToInt32() <> 0)

                    ' Invalidate to get new text painted.
                    Me.Invalidate()

            End Select
            MyBase.WndProc(m)
        End Sub
    End Class
End Namespace

using System;
using System.Drawing;
using System.Windows.Forms;

namespace csTempWindowsApplication1
{
    public class Form1 : System.Windows.Forms.Form
    {
        // Constant value was found in the "windows.h" header
 file.
        private const int
 WM_ACTIVATEAPP = 0x001C;
        private bool appActive = true;

        [STAThread]
        static void Main() 
        {
            Application.Run(new Form1());
        }
        
        public Form1()
        {
            this.Size = new System.Drawing.Size(300
,300);
            this.Text = "Form1";
            this.Font = new System.Drawing.Font("Microsoft
 Sans Serif", 18F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point,
 ((System.Byte)(0)));
        }

        protected override void OnPaint(PaintEventArgs
 e) 
        {
            // Paint a string in different styles depending on whether
 the
            // application is active.
            if (appActive) 
            {
                e.Graphics.FillRectangle(SystemBrushes.ActiveCaption,20,20,260,50);
                e.Graphics.DrawString("Application is active", this.Font,
 SystemBrushes.ActiveCaptionText, 20,20);
            }
            else 
            {
                e.Graphics.FillRectangle(SystemBrushes.InactiveCaption,20,20,260
,50);
                e.Graphics.DrawString("Application is Inactive", this.Font,
 SystemBrushes.ActiveCaptionText, 20,20);
            }
        }

    [System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand,
 Name="FullTrust")]
        protected override void WndProc(ref
 Message m) 
        {
            // Listen for operating system messages.
            switch (m.Msg)
            {
                // The WM_ACTIVATEAPP message occurs when the application
                // becomes the active application or becomes inactive.
                case WM_ACTIVATEAPP:

                    // The WParam value identifies what is occurring.
                    appActive = (((int)m.WParam != 0));

                    // Invalidate to get new text painted.
                    this.Invalidate();

                    break;                
            }
            base.WndProc(ref m);
        }
    }
}

C++

using namespace System;
using namespace System::Drawing;
using namespace System::Windows::Forms;
using namespace System::Security::Permissions;

namespace csTempWindowsApplication1
{
   public ref class Form1: public
 System::Windows::Forms::Form
   {
   private:

      // Constant value was found in the "windows.h" header
 file.
      static const Int32 WM_ACTIVATEAPP = 0x001C;
      Boolean appActive;

   public:
      Form1()
      {
         appActive = true;
         this->Size = System::Drawing::Size( 300, 300 );
         this->Text = "Form1";
         this->Font = gcnew System::Drawing::Font( "Microsoft
 Sans Serif",18.0F,System::Drawing::FontStyle::Bold,System::Drawing::GraphicsUnit::Point,((System::Byte)(0))
 );
      }


   protected:
      virtual void OnPaint( PaintEventArgs^ e ) override
      {
         
         // Paint a string in different styles depending on whether
 the
         // application is active.
         if ( appActive )
         {
            e->Graphics->FillRectangle( SystemBrushes::ActiveCaption, 20, 20,
 260, 50 );
            e->Graphics->DrawString( "Application is active", this->Font,
 SystemBrushes::ActiveCaptionText, 20, 20 );
         }
         else
         {
            e->Graphics->FillRectangle( SystemBrushes::InactiveCaption, 20,
 20, 260, 50 );
            e->Graphics->DrawString( "Application is Inactive", this->Font,
 SystemBrushes::ActiveCaptionText, 20, 20 );
         }
      }


      [SecurityPermission(SecurityAction::Demand, Flags=SecurityPermissionFlag::UnmanagedCode)]
      virtual void WndProc( Message% m ) override
      {
         
         // Listen for operating system messages.
         switch ( m.Msg )
         {
            case WM_ACTIVATEAPP:
               
               // The WParam value identifies what is occurring.
               appActive = (int)m.WParam != 0;
               
               // Invalidate to get new text painted.
               this->Invalidate();
               break;
         }
         Form::WndProc( m );
      }

   };

}


[STAThread]
int main()
{
   Application::Run( gcnew csTempWindowsApplication1::Form1 );
}

package JSLTempWindowsApplication1; 

import System.*;
import System.Drawing.*;
import System.Windows.Forms.*;
import System.Security.Permissions.*;

public class Form1 extends System.Windows.Forms.Form
{
    // Constant value was found in the "windows.h" header
 file.
    private final int WM_ACTIVATEAPP = 0x1C;
    private boolean appActive = true;

    /** @attribute STAThread()
     */
    public static void main(String[]
 args)
    {
        Application.Run(new Form1());
    } //main

    public Form1()
    {
        this.set_Size(new System.Drawing.Size(300,
 300));
        this.set_Text("Form1");
        this.set_Font(new System.Drawing.Font("Microsoft
 Sans Serif", 18, 
            System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 
            (ubyte)0));
    } //Form1

    protected void OnPaint(PaintEventArgs e)
    {
        // Paint a string in different styles depending on whether the
        // application is active.
        if (appActive) {
            e.get_Graphics().FillRectangle(SystemBrushes.get_ActiveCaption(), 
                20, 20, 260, 50);
            e.get_Graphics().DrawString("Application is active", 
                this.get_Font(), SystemBrushes.get_ActiveCaptionText()
,
 
                20, 20);
        }
        else {
            e.get_Graphics().FillRectangle(SystemBrushes.get_InactiveCaption(), 
                20, 20, 260, 50);
            e.get_Graphics().DrawString("Application is Inactive", 
                this.get_Font(), SystemBrushes.get_ActiveCaptionText()
,
                20, 20);
        }
    } //OnPaint

    /** @attribute SecurityPermissionAttribute(SecurityAction.Demand, Flags=SecurityPermissionFlag.UnmanagedCode)
    */
    protected void WndProc(/** @ref */Message
 m)
    {
        // Listen for operating system messages.
        switch (m.get_Msg()) {
            // The WM_ACTIVATEAPP message occurs when the application
            // becomes the active application or becomes inactive.
            case WM_ACTIVATEAPP:
                // The WParam value identifies what is occurring.
                appActive = m.get_WParam().ToInt32() != 0;
                // Invalidate to get new text painted.
                this.Invalidate();
                break;
        }
        super.WndProc(m);
    } //WndProc
} //Form1