CreateParams CreateParams CreateParams CreateParams Class

Definition

Kapselt die für die Erstellung eines Steuerelements benötigten Informationen.Encapsulates the information needed when creating a control.

public ref class CreateParams
public class CreateParams
type CreateParams = class
Public Class CreateParams
Vererbung
CreateParamsCreateParamsCreateParamsCreateParams

Beispiele

Im folgenden Codebeispiel wird eine Button abgeleitete Klasse MyIconButton mit dem Namen erstellt und die Implementierung bereitstellt, die erforderlich ist, damit die Schaltfläche anstelle eines Bilds ein Symbol anzeigt.The following code example creates a Button derived class named MyIconButton and provides the implementation needed for the button to display an Icon rather than an Image. Die CreateParams -Eigenschaft wird erweitert, und ein Wert, Style der der-Eigenschaft hinzugefügt wird, Icon die bewirkt, Imagedass die Schaltfläche anstelle eines anzeigt.The CreateParams property is extended and a value added to the Style property that causes the button to display an Icon rather than an Image.

#include <windows.h>

#using <System.dll>
#using <System.Drawing.dll>
#using <System.Windows.Forms.dll>

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

public ref class MyIconButton: public Button
{
private:
   Icon^ icon;

public:
   MyIconButton()
   {
      
      // Set the button's FlatStyle property.
      FlatStyle = ::FlatStyle::System;
   }

   MyIconButton( Icon^ ButtonIcon )
   {
      
      // Set the button's FlatStyle property.
      FlatStyle = ::FlatStyle::System;
      
      // Assign the icon to the private field.
      this->icon = ButtonIcon;
      
      // Size the button to 4 pixels larger than the icon.
      this->Height = icon->Height + 4;
      this->Width = icon->Width + 4;
   }


protected:

   property System::Windows::Forms::CreateParams^ CreateParams 
   {

      virtual System::Windows::Forms::CreateParams^ get() override
      {
         
         // Extend the CreateParams property of the Button class.
         System::Windows::Forms::CreateParams^ cp = __super::CreateParams;

         // Update the button Style.
         cp->Style |= 0x00000040; // BS_ICON value
         return cp;
      }
   }

public:
   property System::Drawing::Icon^ Icon
   {
      System::Drawing::Icon^ get()
      {
         return icon;
      }
      void set(System::Drawing::Icon^ value)
      {
         icon = value;
         UpdateIcon();
         this->Height = icon->Height + 4;
         this->Width = icon->Width + 4;
      }
   }

protected:
   virtual void OnHandleCreated( EventArgs^ e ) override
   {
      Button::OnHandleCreated( e );
      
      // Update the icon on the button if there is currently an icon assigned to the icon field.
      if ( icon != nullptr )
      {
         UpdateIcon();
      }
   }


private:
   void UpdateIcon()
   {
      IntPtr iconHandle = IntPtr::Zero;
      
      // Get the icon's handle.
      if ( icon != nullptr )
      {
         iconHandle = icon->Handle;
      }

      
      // Send Windows the message to update the button.
      SendMessage( (HWND)Handle.ToPointer(), 0x00F7, 1, (int)iconHandle );
      
      /*BM_SETIMAGE value*/
      /*IMAGE_ICON value*/
   }

   public:
    [DllImport("user32.dll")]
    static LRESULT SendMessage(HWND hWnd, int msg, int wParam, int lParam);

};


using System;
using System.Drawing;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using System.Diagnostics;
using System.IO;
using System.Security.Permissions;

[SecurityPermission(SecurityAction.Demand, UnmanagedCode = true)]
public class MyIconButton : Button
{

    private Icon icon;

    public MyIconButton()
    {
        // Set the button's FlatStyle property.
        FlatStyle = FlatStyle.System;
    }

    public MyIconButton(Icon ButtonIcon)
        : this()
    {
        // Assign the icon to the private field.   
        this.icon = ButtonIcon;


        // Size the button to 4 pixels larger than the icon.
        this.Height = icon.Height + 4;
        this.Width = icon.Width + 4;
    }

    protected override CreateParams CreateParams
    {
        get
        {
            new SecurityPermission(SecurityPermissionFlag.UnmanagedCode).Demand();

            // Extend the CreateParams property of the Button class.
            CreateParams cp = base.CreateParams;
            // Update the button Style.
            cp.Style |= 0x00000040; // BS_ICON value

            return cp;
        }
    }

    public Icon Icon
    {
        get
        {
            return icon;
        }

        set
        {
            icon = value;
            UpdateIcon();
            // Size the button to 4 pixels larger than the icon.
            this.Height = icon.Height + 4;
            this.Width = icon.Width + 4;
        }
    }

    [SecurityPermission(SecurityAction.Demand, UnmanagedCode = true)]
    protected override void OnHandleCreated(EventArgs e)
    {
        base.OnHandleCreated(e);

        // Update the icon on the button if there is currently an icon assigned to the icon field.
        if (icon != null)
        {
            UpdateIcon();
        }
    }

    private void UpdateIcon()
    {
        IntPtr iconHandle = IntPtr.Zero;

        // Get the icon's handle.
        if (icon != null)
        {
            iconHandle = icon.Handle;
        }

        // Send Windows the message to update the button. 
        SendMessage(Handle, 0x00F7 /*BM_SETIMAGE value*/, 1 /*IMAGE_ICON value*/, (int)iconHandle);
    }


    // Import the SendMessage method of the User32 DLL.   
    [DllImport("user32.dll", CharSet = CharSet.Auto)]
    public static extern IntPtr SendMessage(IntPtr hWnd, int msg, int wParam, int lParam);

}
Imports System.Windows.Forms
Imports System.Drawing
Imports System.IO
Imports System.Security.Permissions

Public Class MyIconButton
    Inherits Button

    Private ButtonIcon As Icon

    Public Sub New()
        MyBase.New()

        ' Set the button's FlatStyle property.
        Me.FlatStyle = System.Windows.Forms.FlatStyle.System
    End Sub

    Public Sub New(ByVal Icon As Icon)
        MyBase.New()

        ' Assign the icon to the private field.   
        Me.ButtonIcon = Icon

        ' Size the button to 4 pixels larger than the icon.
        Me.Height = ButtonIcon.Height + 4
        Me.Width = ButtonIcon.Width + 4
    End Sub


    Protected Overrides ReadOnly Property CreateParams() As System.Windows.Forms.CreateParams
        Get
            Dim SecPerm As New SecurityPermission(SecurityPermissionFlag.UnmanagedCode)
            SecPerm.Demand()

            ' Extend the CreateParams property of the Button class.
            Dim cp As System.Windows.Forms.CreateParams = MyBase.CreateParams
            ' Update the button Style.
            cp.Style = cp.Style Or &H40 ' BS_ICON value

            Return cp
        End Get
    End Property

    Public Property Icon() As Icon
        Get
            Return ButtonIcon
        End Get

        Set(ByVal Value As Icon)
            ButtonIcon = Value
            UpdateIcon()
            ' Size the button to 4 pixels larger than the icon.
            Me.Height = ButtonIcon.Height + 4
            Me.Width = ButtonIcon.Width + 4
        End Set
    End Property

    <SecurityPermission(SecurityAction.Demand, UnmanagedCode := True)> _
    Protected Overrides Sub OnHandleCreated(ByVal e As EventArgs)
        MyBase.OnHandleCreated(e)

        ' Update the icon on the button if there is currently an icon assigned to the icon field.
        If Me.ButtonIcon IsNot Nothing Then
            UpdateIcon()
        End If
    End Sub

    Private Sub UpdateIcon()
        Dim IconHandle As IntPtr = IntPtr.Zero

        ' Get the icon's handle.
        If Me.Icon IsNot Nothing Then
            IconHandle = Icon.Handle
        End If

        ' Send Windows the message to update the button. 
        ' BM_SETIMAGE (second parameter) and IMAGE_ICON (third parameter).
        SendMessage(Handle, &HF7, &H1, IconHandle.ToInt32())
    End Sub

    ' Declare the SendMessage function.
    Declare Auto Function SendMessage Lib "user32" (ByVal hWnd As IntPtr, _
            ByVal msg As Integer, ByVal wParam As Integer, ByVal lParam As Integer) As IntPtr
End Class

Im folgenden Codebeispiel wird eine Instanz eines Standard Button Steuer Elements und eine Instanz des abgeleiteten MyIconButtonSteuer Elements erstellt, die im obigen Beispiel erstellt wurde.The following code example creates an instance of a standard Button control and an instance of the derived control, MyIconButton, created in the example above. Für dieses Beispiel ist es erforderlich, Icon dass eine Datei mit dem Namen default. ico am gleichen Speicherort wie die Anwendung vorhanden ist.This example requires that there is an Icon file named Default.ico in the same location as the application. Wenn die Anwendung gestartet wird, Default wird das Symbol auf der MyIconButton Schaltfläche angezeigt.When the application starts, the Default icon is displayed on the MyIconButton button. Wenn das Default Symbol nicht vorhanden ist, ist das Schaltflächen Feld leer.If the Default icon is not present, the button face is blank. Wenn auf den Button Standard geklickt wird, OpenFileDialog wird ein Feld angezeigt, in dem Sie ein neues Symbol auswählen können, MyIconButtondas auf dem angezeigt werden soll.When the standard Button is clicked, an OpenFileDialog box will appear so you can select a new Icon to display on the MyIconButton.

public ref class MyApplication: public Form
{
private:
   MyIconButton^ myIconButton;
   Button^ stdButton;
   OpenFileDialog^ openDlg;

public:
   MyApplication()
   {
      try
      {
         
         // Create the button with the default icon.
         myIconButton = gcnew MyIconButton( gcnew System::Drawing::Icon( String::Concat( Application::StartupPath, "\\Default.ico" ) ) );
      }
      catch ( Exception^ ex ) 
      {
         
         // If the default icon does not exist, create the button without an icon.
         myIconButton = gcnew MyIconButton;
         #if defined(DEBUG)
         Debug::WriteLine( ex );
         #endif
      }
      finally
      {
         stdButton = gcnew Button;
         
         // Add the Click event handlers.
         myIconButton->Click += gcnew EventHandler( this, &MyApplication::myIconButton_Click );
         stdButton->Click += gcnew EventHandler( this, &MyApplication::stdButton_Click );
         
         // Set the location, text and width of the standard button.
         stdButton->Location = Point(myIconButton->Location.X,myIconButton->Location.Y + myIconButton->Height + 20);
         stdButton->Text = "Change Icon";
         stdButton->Width = 100;
         
         // Add the buttons to the Form.
         this->Controls->Add( stdButton );
         this->Controls->Add( myIconButton );
      }

   }


private:
   void myIconButton_Click( Object^ /*Sender*/, EventArgs^ /*e*/ )
   {
      
#undef MessageBox 
      
      // Make sure MyIconButton works.
      MessageBox::Show( "MyIconButton was clicked!" );
   }

   void stdButton_Click( Object^ /*Sender*/, EventArgs^ /*e*/ )
   {
      
      // Use an OpenFileDialog to allow the user to assign a new image to the derived button.
      openDlg = gcnew OpenFileDialog;
      openDlg->InitialDirectory = Application::StartupPath;
      openDlg->Filter = "Icon files (*.ico)|*.ico";
      openDlg->Multiselect = false;
      openDlg->ShowDialog();
      if (  !openDlg->FileName->Equals( "" ) )
      {
         myIconButton->Icon = gcnew System::Drawing::Icon( openDlg->FileName );
      }
   }

};

int main()
{
   Application::Run( gcnew MyApplication );
}

public class MyApplication : Form
{
    private MyIconButton myIconButton;
    private Button stdButton;
    private OpenFileDialog openDlg;

    static void Main()
    {
        Application.Run(new MyApplication());
    }

    public MyApplication()
    {
        try
        {
            // Create the button with the default icon.
            myIconButton = new MyIconButton(new Icon(Application.StartupPath + "\\Default.ico"));
        }
        catch (Exception ex)
        {
            // If the default icon does not exist, create the button without an icon.
            myIconButton = new MyIconButton();
            Debug.WriteLine(ex.ToString());
        }
        finally
        {
            stdButton = new Button();

            // Add the Click event handlers.
            myIconButton.Click += new EventHandler(this.myIconButton_Click);
            stdButton.Click += new EventHandler(this.stdButton_Click);

            // Set the location, text and width of the standard button.
            stdButton.Location = new Point(myIconButton.Location.X, myIconButton.Location.Y + myIconButton.Height + 20);
            stdButton.Text = "Change Icon";
            stdButton.Width = 100;

            // Add the buttons to the Form.
            this.Controls.Add(stdButton);
            this.Controls.Add(myIconButton);
        }

    }

    private void myIconButton_Click(object Sender, EventArgs e)
    {
        // Make sure MyIconButton works.
        MessageBox.Show("MyIconButton was clicked!");
    }

    private void stdButton_Click(object Sender, EventArgs e)
    {
        // Use an OpenFileDialog to allow the user to assign a new image to the derived button.
        openDlg = new OpenFileDialog();
        openDlg.InitialDirectory = Application.StartupPath;
        openDlg.Filter = "Icon files (*.ico)|*.ico";
        openDlg.Multiselect = false;
        openDlg.ShowDialog();

        if (openDlg.FileName != "")
        {
            myIconButton.Icon = new Icon(openDlg.FileName);
        }
    }

}
Public Class Form1
    Inherits System.Windows.Forms.Form

    Friend WithEvents MyStdButton As System.Windows.Forms.Button
    Friend WithEvents MyIconButton As MyIconButton
    Friend WithEvents OpenDlg As OpenFileDialog

    Public Sub New()
        MyBase.New()
        Try
            ' Create the button with the default icon.
            MyIconButton = New MyIconButton(New Icon(Application.StartupPath + "\Default.ico"))

        Catch ex As Exception
            ' If the default icon does not exist, create the button without an icon.
            MyIconButton = New MyIconButton()
            System.Diagnostics.Debug.WriteLine(ex.ToString())
        Finally
            MyStdButton = New Button()

            'Set the location, text and width of the standard button.
            MyStdButton.Location = New Point(MyIconButton.Location.X, _
                        MyIconButton.Location.Y + MyIconButton.Height + 20)
            MyStdButton.Text = "Change Icon"
            MyStdButton.Width = 100

            ' Add the buttons to the Form.
            Me.Controls.Add(MyStdButton)
            Me.Controls.Add(MyIconButton)
        End Try

    End Sub

    Public Shared Sub Main()
        Application.Run(New Form1())
    End Sub

    Private Sub MyStdButton_Click(ByVal sender As System.Object, _
                ByVal e As System.EventArgs) Handles MyStdButton.Click
        ' Use an OpenFileDialog to allow the user to assign a new image to the derived button.
        OpenDlg = New OpenFileDialog()
        OpenDlg.InitialDirectory = Application.StartupPath
        OpenDlg.Filter = "Icon files (*.ico)|*.ico"
        OpenDlg.Multiselect = False
        OpenDlg.ShowDialog()

        If OpenDlg.FileName <> "" Then
            MyIconButton.Icon = New Icon(OpenDlg.FileName)
        End If
    End Sub

    Private Sub MyIconButton_Click(ByVal sender As System.Object, _
                ByVal e As System.EventArgs) Handles MyIconButton.Click
        ' Make sure MyIconButton works.
        MessageBox.Show("MyIconButton was clicked!")
    End Sub
End Class

Hinweise

Die Informationen in einem CreateParams können verwendet werden, um Informationen über den Anfangszustand und das Aussehen eines Steuer Elements zu übergeben.The information in a CreateParams can be used to pass information about the initial state and appearance of a control. Die Control meisten abgeleiteten Steuer CreateParams Elemente überschreiben die-Eigenschaft, um die entsprechenden Werte zu übergeben CreateParams, oder fügen zusätzliche Informationen in den ein.Most Control derived controls override the CreateParams property to pass in the appropriate values or include additional information in the CreateParams.

Weitere Informationen zum Erstellen von Steuerelement Parametern finden Sie CreateWindow unter CreateWindowEx den Funktionen und CREATESTRUCT und der Struktur Dokumentation in der Windows Platform SDK-Referenz in der MSDN Library.For more information about creating control parameters, see the CreateWindow and CreateWindowEx functions and the CREATESTRUCT structure documentation in the Windows Platform SDK reference located in the MSDN Library.

Hinweis

Die Konstanten, die zum Festlegen Styleder ExStyleEigenschaften, ClassStyle und verwendet werden, werden in der Header Datei WinUser. h definiert.The constants used to set the Style, ExStyle, and ClassStyle properties are defined in the Winuser.h header file. Diese Datei wird vom Platform SDK oder von Visual Studio installiert.This file is installed by the Platform SDK or Visual Studio.

Konstruktoren

CreateParams() CreateParams() CreateParams() CreateParams()

Initialisiert eine neue Instanz der CreateParams-Klasse.Initializes a new instance of the CreateParams class.

Eigenschaften

Caption Caption Caption Caption

Ruft den Ausgangstext des Steuerelements ab oder legt diesen fest.Gets or sets the control's initial text.

ClassName ClassName ClassName ClassName

Ruft den Namen der Windows-Klasse ab, von der das Steuerelement abgeleitet werden soll, oder legt diesen fest.Gets or sets the name of the Windows class to derive the control from.

ClassStyle ClassStyle ClassStyle ClassStyle

Ruft eine bitweise Kombination der Klassenstilwerte ab oder legt diese fest.Gets or sets a bitwise combination of class style values.

ExStyle ExStyle ExStyle ExStyle

Ruft eine bitweise Kombination der Werte für den erweiterten Fensterstil ab oder legt diese fest.Gets or sets a bitwise combination of extended window style values.

Height Height Height Height

Ruft die Ausgangshöhe des Steuerelements ab oder legt diese fest.Gets or sets the initial height of the control.

Param Param Param Param

Ruft zusätzliche Parameterinformationen ab, die für die Erstellung des Steuerelements benötigt werden, oder legt diese fest.Gets or sets additional parameter information needed to create the control.

Parent Parent Parent Parent

Ruft das übergeordnete Steuerelement des Steuerelements ab oder legt dieses fest.Gets or sets the control's parent.

Style Style Style Style

Ruft eine bitweise Kombination der Fensterstilwerte ab oder legt diese fest.Gets or sets a bitwise combination of window style values.

Width Width Width Width

Ruft die Ausgangsbreite des Steuerelements ab oder legt diese fest.Gets or sets the initial width of the control.

X X X X

Ruft die linke Anfangsposition des Steuerelements ab oder legt diese fest.Gets or sets the initial left position of the control.

Y Y Y Y

Ruft die obere Anfangsposition des Steuerelements ab oder legt diese fest.Gets or sets the top position of the initial location of the control.

Methoden

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

Bestimmt, ob das angegebene Objekt mit dem aktuellen Objekt identisch ist.Determines whether the specified object is equal to the current object.

(Inherited from Object)
GetHashCode() GetHashCode() GetHashCode() GetHashCode()

Fungiert als Standardhashfunktion.Serves as the default hash function.

(Inherited from Object)
GetType() GetType() GetType() GetType()

Ruft den Type der aktuellen Instanz ab.Gets the Type of the current instance.

(Inherited from Object)
MemberwiseClone() MemberwiseClone() MemberwiseClone() MemberwiseClone()

Erstellt eine flache Kopie des aktuellen Object.Creates a shallow copy of the current Object.

(Inherited from Object)
ToString() ToString() ToString() ToString()

Gibt eine Zeichenfolge zurück, die das aktuelle Objekt darstellt.Returns a string that represents the current object.

Gilt für:

Siehe auch