public void Dispose()
{
// Dispose() can throw. As such we'll suppress preemptively so we don't roll right back in and
// potentially throw again on the finalizer thread.
SuppressFinalize();
// We need to dispose of the WindowsGraphics if it is created by this class only, if the IDeviceContext is
// a WindowsGraphics object we must not dispose of it since it is owned by the caller.
if (_windowsGraphics != null && _windowsGraphics != _deviceContext)
{
try
{
_windowsGraphics.Dispose();
}
finally
{
// Always make an attempt to release the HDC.
_deviceContext?.ReleaseHdc();
}
}
// Clear our fields that have finalizers
_deviceContext = null;
_windowsGraphics = null;
}
/// <devdoc>
/// Dispose of cached memory dc.
/// </devdoc>
public static void ResetMeasurementGraphics()
{
if (measurementGraphics != null)
{
#if TRACK_HDC
//Debug.WriteLine( DbgUtil.StackTraceToStr(string.Format("Disposing measurement DC and WG for thread: [0x{0:x8}]", Thread.CurrentThread.ManagedThreadId)));
Debug.WriteLine(DbgUtil.StackTraceToStr("Disposing measurement DC and WG"));
#endif
measurementGraphics.Dispose();
measurementGraphics = null;
}
}
internal void DrawUnstretched(Graphics graphics, Rectangle targetRect)
{
Rectangle rectangle = targetRect;
rectangle.X += (int)graphics.Transform.OffsetX;
rectangle.Y += (int)graphics.Transform.OffsetY;
WindowsGraphics graphics2 = WindowsGraphics.FromGraphics(graphics, ApplyGraphicsProperties.Clipping);
IntPtr hdc = graphics2.GetHdc();
try
{
this.DrawIcon(hdc, Rectangle.Empty, rectangle, false);
}
finally
{
graphics2.Dispose();
}
}
/// <include file='doc\Icon.uex' path='docs/doc[@for="Icon.DrawUnstretched"]/*' />
/// <devdoc>
/// Draws this image to a graphics object. The drawing command originates on the graphics
/// object, but a graphics object generally has no idea how to render a given image. So,
/// it passes the call to the actual image. This version crops the image to the given
/// dimensions and allows the user to specify a rectangle within the image to draw.
/// </devdoc>
internal void DrawUnstretched(Graphics graphics, Rectangle targetRect)
{
Rectangle copy = targetRect;
copy.X += (int)graphics.Transform.OffsetX;
copy.Y += (int)graphics.Transform.OffsetY;
WindowsGraphics wg = WindowsGraphics.FromGraphics(graphics, ApplyGraphicsProperties.Clipping);
IntPtr dc = wg.GetHdc();
try
{
DrawIcon(dc, Rectangle.Empty, copy, false);
}
finally
{
wg.Dispose();
}
}
public void Dispose(bool disposing)
{
Debug.Assert(disposing, "We should always dispose of this guy and not let GC do it for us!");
if (wg != null)
{
// We need to dispose of the WindowsGraphics if it is created by this class only, if the IDeviceContext is
// a WindowsGraphics object we must not dispose of it since it is owned by the caller.
if (wg != idc)
{
// resets the hdc and disposes of the internal Graphics (if inititialized from one) which releases the hdc.
wg.Dispose();
if (idc != null) // not initialized from a Graphics idc.
{
idc.ReleaseHdc();
}
}
idc = null;
wg = null;
}
}