Message.Msg-Eigenschaft

Ruft die ID-Nummer der Meldung ab oder legt diese fest.

Namespace: System.Windows.Forms
Assembly: System.Windows.Forms (in system.windows.forms.dll)

Syntax

'Declaration
Public Property Msg As Integer
'Usage
Dim instance As Message
Dim value As Integer

value = instance.Msg

instance.Msg = value

public int Msg { get; set; }

public:
property int Msg {
    int get ();
    void set (int value);
}

/** @property */
public int get_Msg ()

/** @property */
public void set_Msg (int value)

public function get Msg () : int

public function set Msg (value : int)

Eigenschaftenwert

Die ID-Nummer der Meldung.

Beispiel

Im folgenden Codebeispiel wird das Überschreiben der WndProc-Methode zum Behandeln von in der Message angegebenen Betriebssystemmeldungen veranschaulicht. In diesem Beispiel wird die Betriebssystemmeldung WM_ACTIVATEAPP behandelt, um zu ermitteln, wann eine andere Anwendung aktiviert wird. In der Platform SDK-Dokumentation der MSDN Library finden Sie Informationen zu den verfügbaren Werten Message.Msg, Message.LParam und Message.WParam. Die tatsächlichen konstanten Werte finden Sie in der Headerdatei Windows.h, die Sie im Download des Platform SDK (Abschnitt Core SDK) und im MSDN finden.

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);
        }
    }
}

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

Plattformen

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile für Pocket PC, Windows Mobile für Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

.NET Framework unterstützt nicht alle Versionen sämtlicher Plattformen. Eine Liste der unterstützten Versionen finden Sie unter Systemanforderungen.

Versionsinformationen

.NET Framework

Unterstützt in: 2.0, 1.1, 1.0

Siehe auch

Referenz

Message-Struktur
Message-Member
System.Windows.Forms-Namespace