Message.WParam プロパティ
メッセージの WParam フィールドを取得または設定します。
名前空間: System.Windows.Forms
アセンブリ: System.Windows.Forms (system.windows.forms.dll 内)
構文
'宣言
Public Property WParam As IntPtr
'使用
Dim instance As Message
Dim value As IntPtr
value = instance.WParam
instance.WParam = value
public IntPtr WParam { get; set; }
public:
property IntPtr WParam {
IntPtr get ();
void set (IntPtr value);
}
/** @property */
public IntPtr get_WParam ()
/** @property */
public void set_WParam (IntPtr value)
public function get WParam () : IntPtr
public function set WParam (value : IntPtr)
プロパティ値
メッセージの WParam フィールド。
解説
このフィールドの値は、メッセージによって異なります。WParam フィールドを使用して、メッセージを処理するために重要となる情報を取得します。通常、このフィールドは、フラグなどの小規模の情報を格納するために使用されます。
使用例
WndProc メソッドをオーバーライドして、Message 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 ライブラリから入手でき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 ファイルに記載されています。これは MSDN からも入手できます。
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
プラットフォーム
Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, 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