Message Message Message Message Struct

Definição

Implementa uma mensagem do Windows.Implements a Windows message.

public value class Message
public struct Message
type Message = struct
Public Structure Message
Herança

Exemplos

O exemplo de código a seguir demonstra WndProc a substituição do método para manipular as mensagens do Messagesistema operacional identificadas no.The following code example demonstrates overriding the WndProc method to handle operating system messages identified in the Message. A mensagem do sistema operacional WM_ACTIVATEAPP é tratada neste exemplo para saber quando outro aplicativo está ficando ativo.The WM_ACTIVATEAPP operating system message is handled in this example to know when another application is becoming active. Para obter informações sobre os Message.Msgvalores Message.LParam, e Message.WParam disponíveis, consulte a documentação da estrutura msg .For information about the available Message.Msg, Message.LParam, and Message.WParam values, see the MSG Structure documentation. Para obter informações sobre os valores constantes reais, consulte constantes de mensagem.For information about the actual constant values, see Message Constants.

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 );
}

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);
        }
    }
}
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

        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

Comentários

A Message estrutura encapsula as mensagens que o Windows envia.The Message structure wraps messages that Windows sends. Você pode usar essa estrutura para encapsular uma mensagem e atribuí-la ao procedimento de janela a ser expedida.You can use this structure to wrap a message and assign it to the window procedure to be dispatched. Você também pode usar essa estrutura para obter informações sobre uma mensagem que o sistema envia para seu aplicativo ou controles.You can also use this structure to get information about a message the system sends to your application or controls. Para obter mais informações sobre mensagens do Windows, consulte mensagens e filasde mensagens.For more information about Windows messages, see Messages and Message Queues.

Você não pode criar Message o diretamente.You cannot create the Message directly. Em vez disso, Create use o método.Instead, use the Create method. Para fins de eficiência, o Message usa seu pool de s existentes Messageem vez de instanciar um novo, se possível.For the sake of efficiency, the Message uses its pool of existing Messages instead of instantiating a new one, if possible. No entanto, Message se um não estiver disponível no pool, um novo será instanciado.However, if a Message is not available in the pool, a new one is instantiated.

Propriedades

HWnd HWnd HWnd HWnd

Obtém ou define o identificador de janela da mensagem.Gets or sets the window handle of the message.

LParam LParam LParam LParam

Especifica o campo LParam da mensagem.Specifies the LParam field of the message.

Msg Msg Msg Msg

Obtém ou define o número da ID da mensagem.Gets or sets the ID number for the message.

Result Result Result Result

Especifica o valor retornado para o Windows em resposta para lidar com a mensagem.Specifies the value that is returned to Windows in response to handling the message.

WParam WParam WParam WParam

Obtém ou define o campo WParam da mensagem.Gets or sets the WParam field of the message.

Métodos

Create(IntPtr, Int32, IntPtr, IntPtr) Create(IntPtr, Int32, IntPtr, IntPtr) Create(IntPtr, Int32, IntPtr, IntPtr) Create(IntPtr, Int32, IntPtr, IntPtr)

Cria um novo Message.Creates a new Message.

Equals(Object) Equals(Object) Equals(Object) Equals(Object)

Determina se o objeto especificado é igual ao objeto atual.Determines whether the specified object is equal to the current object.

GetHashCode() GetHashCode() GetHashCode() GetHashCode()

Retorna o código hash para essa instância.Returns the hash code for this instance.

GetLParam(Type) GetLParam(Type) GetLParam(Type) GetLParam(Type)

Obtém o valor LParam e converte-o em um objeto.Gets the LParam value and converts the value to an object.

ToString() ToString() ToString() ToString()

Retorna um String que representa o Message atual.Returns a String that represents the current Message.

Operadores

Equality(Message, Message) Equality(Message, Message) Equality(Message, Message) Equality(Message, Message)

Determina se duas instâncias de Message são iguais.Determines whether two instances of Message are equal.

Inequality(Message, Message) Inequality(Message, Message) Inequality(Message, Message) Inequality(Message, Message)

Determina se duas instâncias de Message não são iguais.Determines whether two instances of Message are not equal.

Aplica-se a

Veja também