Message Message Message Message Struct

定义

实现 Windows 消息。Implements a Windows message.

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

示例

下面的代码示例演示如何重WndProc写方法以处理中标识的Message操作系统消息。The following code example demonstrates overriding the WndProc method to handle operating system messages identified in the Message. 在此示例中处理 WM_ACTIVATEAPP 操作系统消息, 以了解其他应用程序何时变为活动状态。The WM_ACTIVATEAPP operating system message is handled in this example to know when another application is becoming active. 有关可用Message.Msg的、 Message.LParamMessage.WParam值的信息, 请参阅消息结构文档。For information about the available Message.Msg, Message.LParam, and Message.WParam values, see the MSG Structure documentation. 有关实际常数值的信息, 请参阅消息常量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 '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

注解

Message结构包装 Windows 发送的消息。The Message structure wraps messages that Windows sends. 您可以使用此结构来包装消息, 并将其分配给要调度的窗口过程。You can use this structure to wrap a message and assign it to the window procedure to be dispatched. 你还可以使用此结构来获取有关系统发送到你的应用程序或控件的消息的信息。You can also use this structure to get information about a message the system sends to your application or controls. 有关 Windows 消息的详细信息, 请参阅消息和消息队列For more information about Windows messages, see Messages and Message Queues.

不能Message直接创建。You cannot create the Message directly. Create改用方法。Instead, use the Create method. 为了提高效率, Message使用其现有Message的池, 而不是实例化新的池 (如果可能)。For the sake of efficiency, the Message uses its pool of existing Messages instead of instantiating a new one, if possible. 但是, 如果池中Message没有可用的, 则会实例化一个新的。However, if a Message is not available in the pool, a new one is instantiated.

属性

HWnd HWnd HWnd HWnd

获取或设置消息的窗口句柄。Gets or sets the window handle of the message.

LParam LParam LParam LParam

指定消息的 LParam 字段。Specifies the LParam field of the message.

Msg Msg Msg Msg

获取或设置消息的 ID 号。Gets or sets the ID number for the message.

Result Result Result Result

指定为响应消息处理而向 Windows 返回的值。Specifies the value that is returned to Windows in response to handling the message.

WParam WParam WParam WParam

获取或设置消息的 WParam 字段。Gets or sets the WParam field of the message.

方法

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

创建一个新的 MessageCreates a new Message.

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

确定指定的对象是否等于当前对象。Determines whether the specified object is equal to the current object.

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

返回此实例的哈希代码。Returns the hash code for this instance.

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

获取 LParam 值,并将其转换为对象。Gets the LParam value and converts the value to an object.

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

返回一个 String,表示当前的 MessageReturns a String that represents the current Message.

操作员

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

确定两个 Message 实例是否相等。Determines whether two instances of Message are equal.

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

确定两个 Message 实例是否不相等。Determines whether two instances of Message are not equal.

适用于

另请参阅