NativeWindow クラス

[アーティクル]
03/28/2008

ウィンドウハンドルとウィンドウプロシージャの低水準のカプセル化を提供します。

この型のすべてのメンバの一覧については、NativeWindow メンバを参照してください。

System.Object
System.MarshalByRefObject
System.Windows.Forms.NativeWindow

Public Class NativeWindow
   Inherits MarshalByRefObject
[C#]
public class NativeWindow : MarshalByRefObject
[C++]
public __gc class NativeWindow : public MarshalByRefObject
[JScript]
public class NativeWindow extends MarshalByRefObject

スレッドセーフ

この型の public static (Visual Basicでは Shared) のすべてのメンバは、マルチスレッド操作で安全に使用できます。インスタンスのメンバの場合は、スレッドセーフであるとは限りません。

解説

このクラスは、ウィンドウクラスの作成と登録を自動的に管理します。

ウィンドウは、ウィンドウハンドルが関連付けられている場合は、ガベージコレクションの対象にはなりません。適切なガベージコレクションを行うには、ハンドルを DestroyHandle を使用して手動で破棄するか、 ReleaseHandle を使用して解放する必要があります。

NativeWindow クラスには、 Handle 、 CreateHandle 、 AssignHandle 、 DestroyHandle 、 ReleaseHandle など、ハンドルを管理するためのプロシージャやメソッドがあります。

使用例

[Visual Basic, C#, C++] オペレーティングシステムのウィンドウメッセージをウィンドウプロシージャで受け取り、特定のオペレーティングシステムウィンドウクラス名を指定してウィンドウを作成する例を次に示します。この例では、これを達成するために、 NativeWindow の派生クラスを 2 つ作成しています。

[Visual Basic, C#, C++] MyNativeWindowListener クラスは、コンストラクタに渡されたフォームのウィンドウプロシージャにフックし、 WndProc メソッドをオーバーライドして WM_ACTIVATEAPP ウィンドウメッセージを受け取ります。このクラスでは、 NativeWindow が使用するウィンドウハンドルを識別するために AssignHandle メソッドと ReleaseHandle メソッドを使用する方法を示しています。このハンドルは、 Control.HandleCreated イベントと Control.HandleDestroyed イベントを基に割り当てられます。 WM_ACTIVATEAPP ウィンドウメッセージが受信されると、このクラスは form1 ApplicationActivated メソッドを呼び出します。

[Visual Basic, C#, C++] MyNativeWindow クラスは、 ClassName が BUTTON に設定された新しいウィンドウを作成します。このクラスでは、 CreateHandle メソッドを使用し、 WndProc メソッドをオーバーライドして、受信されたウィンドウメッセージを受け取る方法を示しています。

 
Imports System
Imports System.Drawing
Imports System.Windows.Forms
Imports System.Runtime.InteropServices

' Summary description for Form1.
Public Class Form1
    Inherits System.Windows.Forms.Form

    Private nwl As MyNativeWindowListener
    Private nw As MyNativeWindow

    Friend Sub ApplicationActived(ByVal ApplicationActivated As Boolean)
        ' The application has been activated or deactivated
        System.Diagnostics.Debug.WriteLine("Application Active = " + ApplicationActivated.ToString())
    End Sub

    Public Sub New()
        MyBase.New()

        Me.Size = New System.Drawing.Size(300, 300)
        Me.Text = "Form1"

        nwl = New MyNativeWindowListener(Me)
        nw = New MyNativeWindow(Me)

    End Sub

End Class

' NativeWindow class to listen to operating system messages.
Public Class MyNativeWindowListener
    Inherits NativeWindow

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

    Private parent As Form1

    Public Sub New(ByVal parent As Form1)

        AddHandler parent.HandleCreated, AddressOf Me.OnHandleCreated
        AddHandler parent.HandleDestroyed, AddressOf Me.OnHandleDestroyed
        Me.parent = parent
    End Sub

    ' Listen for the control's window creation and hook into it.    
    Private Sub OnHandleCreated(ByVal sender As Object, ByVal e As EventArgs)
        ' Window is now created, assign handle to NativeWindow.
        AssignHandle(CType(sender, Form).Handle)
    End Sub

    Private Sub OnHandleDestroyed(ByVal sender As Object, ByVal e As EventArgs)
        ' Window was destroyed, release hook.
        ReleaseHandle()
    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)
            Case WM_ACTIVATEAPP

                ' Notify the form that this message was received.
                ' Application is activated or deactivated, 
                ' based upon the WParam parameter.
                parent.ApplicationActived(m.WParam.ToInt32() <> 0)

        End Select

        MyBase.WndProc(m)
    End Sub
End Class

' MyNativeWindow class to create a window given a class name.
Public Class MyNativeWindow
    Inherits NativeWindow

    ' Constant values were found in the "windows.h" header file.
    Private Const WS_CHILD As Integer = &H40000000, _
                  WS_VISIBLE As Integer = &H10000000, _
                  WM_ACTIVATEAPP As Integer = &H1C

    private windowHandle as integer

    Public Sub New(ByVal parent As Form)

        Dim cp As CreateParams = New CreateParams()

        ' Fill in the CreateParams details.
        cp.Caption = "Click here"
        cp.ClassName = "Button"

        ' Set the position on the form
        cp.X = 100
        cp.Y = 100
        cp.Height = 100
        cp.Width = 100

        ' Specify the form as the parent.
        cp.Parent = parent.Handle

        ' Create as a child of the specified parent
        cp.Style = WS_CHILD Or WS_VISIBLE

        ' Create the actual window
        Me.CreateHandle(cp)
    End Sub

    ' Listen to when the handle changes to keep the variable in sync
 <System.Security.Permissions.PermissionSetAttribute(System.Security.Permissions.SecurityAction.Demand, Name:="FullTrust")> _
Protected Overrides Sub OnHandleChange()
        windowHandle = Me.Handle.ToInt32()
    End Sub

<System.Security.Permissions.PermissionSetAttribute(System.Security.Permissions.SecurityAction.Demand, Name:="FullTrust")> _
    Protected Overrides Sub WndProc(ByRef m As Message)
        ' Listen for messages that are sent to the button window. Some messages are sent
        ' to the parent window instead of the button's window.

        Select Case (m.Msg)
            Case WM_ACTIVATEAPP
                ' Do something here in response to messages
        End Select

        MyBase.WndProc(m)
    End Sub

End Class

[C#] 
using System;
using System.Drawing;
using System.Windows.Forms;
using System.Runtime.InteropServices;

namespace NativeWindowApplication
{

    // Summary description for Form1.
    public class Form1 : System.Windows.Forms.Form
    {
        private MyNativeWindowListener nwl;
        private MyNativeWindow nw;

        internal void ApplicationActived(bool ApplicationActivated){
            // The application has been activated or deactivated
            System.Diagnostics.Debug.WriteLine("Application Active = " + ApplicationActivated.ToString());
        }

        public Form1()
        {
            this.Size = new System.Drawing.Size(300,300);
            this.Text = "Form1";

            nwl = new MyNativeWindowListener(this);
            nw = new MyNativeWindow(this);
            
        }

        // The main entry point for the application.
        [STAThread]
        static void Main() 
        {
            Application.Run(new Form1());
        }
    }

    // NativeWindow class to listen to operating system messages.
    public class MyNativeWindowListener: NativeWindow{

        // Constant value was found in the "windows.h" header file.
        private const int WM_ACTIVATEAPP = 0x001C;

        private Form1 parent;

        public MyNativeWindowListener(Form1 parent){

            parent.HandleCreated += new EventHandler(this.OnHandleCreated);
            parent.HandleDestroyed+= new EventHandler(this.OnHandleDestroyed);
            this.parent = parent;
        }

        // Listen for the control's window creation and then hook into it.
        internal void OnHandleCreated(object sender, EventArgs e){
            // Window is now created, assign handle to NativeWindow.
            AssignHandle(((Form1)sender).Handle);
        }
        internal void OnHandleDestroyed(object sender, EventArgs e) {
            // Window was destroyed, release hook.
            ReleaseHandle();
        }
    [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){
                case WM_ACTIVATEAPP:

                    // Notify the form that this message was received.
                    // Application is activated or deactivated, 
                    // based upon the WParam parameter.
                    parent.ApplicationActived(((int)m.WParam != 0));

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

    // MyNativeWindow class to create a window given a class name.
    public class MyNativeWindow: NativeWindow{

        // Constant values were found in the "windows.h" header file.
        private const int WS_CHILD = 0x40000000,
                          WS_VISIBLE = 0x10000000,
                          WM_ACTIVATEAPP = 0x001C;
        
        private int windowHandle ;

        public MyNativeWindow(Form parent){

            CreateParams cp = new CreateParams();

            // Fill in the CreateParams details.
            cp.Caption = "Click here";
            cp.ClassName = "Button";
            
            // Set the position on the form
            cp.X = 100;
            cp.Y = 100;
            cp.Height = 100;
            cp.Width = 100;

            // Specify the form as the parent.
            cp.Parent = parent.Handle;
            
            // Create as a child of the specified parent
            cp.Style = WS_CHILD | WS_VISIBLE;

            // Create the actual window
            this.CreateHandle(cp);
        }

        // Listen to when the handle changes to keep the variable in sync
        [System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name="FullTrust")]
        protected override void OnHandleChange(){
            windowHandle  = (int)this.Handle;
        }

    [System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name="FullTrust")]
        protected override void WndProc(ref Message m){
            // Listen for messages that are sent to the button window. Some messages are sent
            // to the parent window instead of the button's window.

            switch (m.Msg){
                case WM_ACTIVATEAPP:
                    // Do something here in response to messages
                    break;
            }
            base.WndProc(ref m);
        }       
    }
}

[C++] 

using namespace System;
using namespace System::Drawing;
using namespace System::Windows::Forms;
using namespace System::Runtime::InteropServices;

__gc class MyNativeWindowListener;
__gc class MyNativeWindow;

// Summary description for Form1.
__gc class Form1 : public System::Windows::Forms::Form {
private:
    MyNativeWindowListener*  nwl;
    MyNativeWindow*  nw;

    public private: 
        void ApplicationActived(bool ApplicationActivated) {
            // The application has been activated or deactivated
            System::Diagnostics::Debug::WriteLine(S"Application Active = {0}", ApplicationActivated.ToString());
        }

public:
    Form1();
};

// NativeWindow class to listen to operating system messages.
__gc class MyNativeWindowListener : public NativeWindow {

    // Constant value was found in the S"windows.h" header file.
private:
    const static int  WM_ACTIVATEAPP = 0x001C;
    Form1*  parent;

public:
    MyNativeWindowListener(Form1* parent) {
        parent->HandleCreated += new EventHandler(this, &MyNativeWindowListener::OnHandleCreated);
        parent->HandleDestroyed += new EventHandler(this, &MyNativeWindowListener::OnHandleDestroyed);
        this->parent = parent;
    }

    public private: 
        // Listen for the control's window creation and then hook into it.
        void OnHandleCreated(Object* sender, EventArgs* /*e*/) {
            // Window is now created, assign handle to NativeWindow.
            AssignHandle((dynamic_cast<Form1*>(sender))->Handle);
        }
        void OnHandleDestroyed(Object* /*sender*/, EventArgs* /*e*/) {
            // Window was destroyed, release hook.
            ReleaseHandle();
        }

protected:
    [System::Security::Permissions::PermissionSet(System::Security::Permissions::SecurityAction::Demand, Name="FullTrust")] 
    void WndProc(Message* m) {
        // Listen for operating system messages

        switch (m->Msg) {
            case WM_ACTIVATEAPP:

                // Notify the form that this message was received.
                // Application is activated or deactivated,
                // based upon the WParam parameter.
                parent->ApplicationActived(((int)m->WParam != 0));

                break;
        }
        NativeWindow::WndProc(m);

    }
};

// MyNativeWindow class to create a window given a class name.
__gc class MyNativeWindow : public NativeWindow {

    // Constant values were found in the S"windows.h" header file.
private:
    const static int
        WS_CHILD = 0x40000000,
        WS_VISIBLE = 0x10000000,
        WM_ACTIVATEAPP = 0x001C;

    int windowHandle;

public:
    MyNativeWindow(Form* parent) {

        CreateParams* cp = new CreateParams();

        // Fill in the CreateParams details.
        cp->Caption = S"Click here";
        cp->ClassName = S"Button";

        // Set the position on the form
        cp->X = 100;
        cp->Y = 100;
        cp->Height = 100;
        cp->Width = 100;

        // Specify the form as the parent.
        cp->Parent = parent->Handle;

        // Create as a child of the specified parent
        cp->Style = WS_CHILD | WS_VISIBLE;

        // Create the actual window
        this->CreateHandle(cp);
    }

protected:
    // Listen to when the handle changes to keep the variable in sync
    [System::Security::Permissions::PermissionSet(System::Security::Permissions::SecurityAction::Demand, Name="FullTrust")] 
    void OnHandleChange() {
        windowHandle  = (int)this->Handle;
    }

    [System::Security::Permissions::PermissionSet(System::Security::Permissions::SecurityAction::Demand, Name="FullTrust")] 
    void WndProc(Message* m) {
        // Listen for messages that are sent to the button window. Some messages are sent
        // to the parent window instead of the button's window.

        switch (m->Msg) {
            case WM_ACTIVATEAPP:
                // Do something here in response to messages
                break;
        }
        NativeWindow::WndProc(m);
    }
};


Form1::Form1() {
    this->Size = System::Drawing::Size(300, 300);
    this->Text = S"Form1";
    nwl = new MyNativeWindowListener(this);
    nw = new MyNativeWindow(this);
}

// The main entry point for the application.
[STAThread]
int main() {
    Application::Run(new Form1());
}

[JScript] JScript のサンプルはありません。Visual Basic、C#、および C++ のサンプルを表示するには、このページの左上隅にある言語のフィルタボタンをクリックします。

必要条件

名前空間: System.Windows.Forms

プラットフォーム: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 ファミリ

アセンブリ: System.Windows.Forms (System.Windows.Forms.dll 内)

.NET Framework セキュリティ:

SecurityPermission (継承クラスがアンマネージコードを呼び出すために必要なアクセス許可) SecurityPermissionFlag.UnmanagedCode (関連する列挙体)
SecurityPermission (直前の呼び出し元がアンマネージコードを呼び出すために必要なアクセス許可) SecurityPermissionFlag.UnmanagedCode (関連する列挙体)

参照

NativeWindow メンバ | System.Windows.Forms 名前空間

次の方法で共有

NativeWindow クラス

スレッドセーフ

解説

使用例

必要条件

参照

その他のリソース