Icon.FromHandle(IntPtr) Metoda

Definice

Obor názvů:

System.Drawing

Sestavení:

System.Drawing.Common.dll

Balíček:

System.Drawing.Common v9.0.0-preview.5.24306.5

Zdroj:

Icon.cs

Vytvoří Icon GDI+ ze zadaného úchytu Windows na ikonu (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

Úchyt windows na ikonu.

Návraty

Icon

Icon tuto metodu vytvoří.

Příklady

Následující příklad kódu je určený pro použití s Windows Forms a vyžaduje PaintEventArgse, což je parametr obslužné rutiny události Paint. Kód provede následující akce:

• Vytvoří Bitmap.

• Nakreslí tento objekt na obrazovku.

• Získá popisovač ikony pro Bitmap.

• Nastaví atribut Form.Icon formuláře na ikonu vytvořenou z úchytu.

• Volá funkci rozhraní Windows API DestroyIcon k uvolnění prostředků.

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

Poznámky

Při použití této metody musíte odstranit původní ikonu pomocí metody DestroyIcon v rozhraní API systému Windows, aby se zajistilo, že jsou prostředky uvolněny.