Język

Icon.FromHandle(IntPtr) Metoda

Definicja

Tworzy interfejs GDI+ Icon z określonego dojścia Windows do ikony (HICON).

public:
 static System::Drawing::Icon ^ FromHandle(IntPtr handle);
public static System.Drawing.Icon FromHandle(IntPtr handle);
static member FromHandle : nativeint -> System.Drawing.Icon
Public Shared Function FromHandle (handle As IntPtr) As Icon

Parametry

handle
IntPtr

nativeint

Uchwyt Windows do ikony.

Zwraca

Ta Icon metoda tworzy.

Przykłady

Poniższy przykład kodu jest przeznaczony do użycia z Windows Forms i wymaga PaintEventArgse, który jest parametrem programu obsługi zdarzeń Paint. Kod wykonuje następujące akcje:

  • Tworzy Bitmap.

  • Rysuje ten obiekt na ekranie.

  • Pobiera uchwyt ikony dla elementu Bitmap.

  • Form.Icon Ustawia atrybut formularza na ikonę utworzoną na podstawie uchwytu.

  • Wywołuje funkcję interfejsu API Windows DestroyIcon w celu wydania zasobów.

private:
   [System::Runtime::InteropServices::DllImportAttribute("user32.dll",CharSet=CharSet::Auto)]
   static bool DestroyIcon( IntPtr handle );

private:
   [SecurityPermission(SecurityAction::Demand, Flags=SecurityPermissionFlag::UnmanagedCode)]
   void GetHicon_Example( PaintEventArgs^ e )
   {
      
      // Create a Bitmap object from an image file.
      Bitmap^ myBitmap = gcnew Bitmap( "c:\\FakePhoto.jpg" );
      
      // Draw myBitmap to the screen.
      e->Graphics->DrawImage( myBitmap, 0, 0 );
      
      // Get an Hicon for myBitmap.
      IntPtr Hicon = myBitmap->GetHicon();
      
      // Create a new icon from the handle. 
      System::Drawing::Icon^ newIcon = ::Icon::FromHandle( Hicon );
      
      // Set the form Icon attribute to the new icon.
      this->Icon = newIcon;
      
      // You can now destroy the Icon, since the form creates
      // its own copy of the icon accesible through the Form.Icon property.
      DestroyIcon( newIcon->Handle );
   }

[System.Runtime.InteropServices.DllImport("user32.dll", CharSet = CharSet.Auto)]
extern static bool DestroyIcon(IntPtr handle);

private void GetHicon_Example(PaintEventArgs e)
{

    // Create a Bitmap object from an image file.
    Bitmap myBitmap = new Bitmap(@"c:\FakePhoto.jpg");

    // Draw myBitmap to the screen.
    e.Graphics.DrawImage(myBitmap, 0, 0);

    // Get an Hicon for myBitmap.
    IntPtr Hicon = myBitmap.GetHicon();

    // Create a new icon from the handle. 
    Icon newIcon = Icon.FromHandle(Hicon);

    // Set the form Icon attribute to the new icon.
    this.Icon = newIcon;

    // You can now destroy the icon, since the form creates
    // its own copy of the icon accessible through the Form.Icon property.
    DestroyIcon(newIcon.Handle);
}
<System.Runtime.InteropServices.DllImportAttribute("user32.dll")> _
    Private Shared Function DestroyIcon(ByVal handle _ 
    As IntPtr) As Boolean 
    End Function

   Private Sub GetHicon_Example(ByVal e As PaintEventArgs)

        ' Create a Bitmap object from an image file.
        Dim myBitmap As New Bitmap("c:\FakePhoto.jpg")

        ' Draw myBitmap to the screen.
        e.Graphics.DrawImage(myBitmap, 0, 0)

        ' Get an Hicon for myBitmap.
        Dim HIcon As IntPtr = myBitmap.GetHicon()
    
        ' Create a new icon from the handle.
        Dim newIcon As Icon = System.Drawing.Icon.FromHandle(HIcon)

        ' Set the form Icon attribute to the new icon.
        Me.Icon = newIcon

        ' You can now destroy the icon, since the form creates its 
        ' own copy of the icon accessible through the Form.Icon property.
    DestroyIcon(newIcon.Handle)
    End Sub

Uwagi

W przypadku korzystania z tej metody należy usunąć oryginalną ikonę przy użyciu metody DestroyIcon w interfejsie API Windows, aby upewnić się, że zasoby są zwalniane.

Dotyczy