Icon.FromHandle(IntPtr) 方法

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

參數

傳回

Icon這種方法會產生。

範例

以下程式碼範例是為 Windows Forms 設計的，並需要 PaintEventArgse，這是 Paint 事件處理程序的參數。 此程式碼會執行下列動作：

• 建立 Bitmap。

• 把那個物件畫到螢幕上。

• 會有一個圖示柄來代表 Bitmap.

• 將表單屬性設定 Form.Icon 為由 handle 建立的圖示。

• 呼叫 Windows API 函式 DestroyIcon 來釋放資源。

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

備註

使用此方法時，必須在 Windows API 中使用 DestroyIcon 方法來處理原始圖示，以確保資源被釋放。