public void RestoreHdc()
{
IntUnsafeNativeMethods.RestoreDC(new HandleRef(this, this.hDC), -1);
if (this.contextStack != null)
{
GraphicsState state = (GraphicsState)this.contextStack.Pop();
this.hCurrentBmp = state.hBitmap;
this.hCurrentBrush = state.hBrush;
this.hCurrentPen = state.hPen;
this.hCurrentFont = state.hFont;
if ((state.font != null) && state.font.IsAlive)
{
this.selectedFont = state.font.Target as WindowsFont;
}
else
{
WindowsFont selectedFont = this.selectedFont;
this.selectedFont = null;
if ((selectedFont != null) && MeasurementDCInfo.IsMeasurementDC(this))
{
selectedFont.Dispose();
}
}
}
MeasurementDCInfo.ResetIfIsMeasurementDC(this.hDC);
}
/// <summary>
/// Restores the device context to the specified state. The DC is restored by popping state information off a
/// stack created by earlier calls to the SaveHdc function.
/// The stack can contain the state information for several instances of the DC. If the state specified by the
/// specified parameter is not at the top of the stack, RestoreDC deletes all state information between the top
/// of the stack and the specified instance.
/// Specifies the saved state to be restored. If this parameter is positive, nSavedDC represents a specific
/// instance of the state to be restored. If this parameter is negative, nSavedDC represents an instance relative
/// to the current state. For example, -1 restores the most recently saved state.
/// See MSDN for more info.
/// </summary>
public void RestoreHdc()
{
#if TRACK_HDC
bool result =
#endif
// Note: Don't use the Hdc property here, it would force handle creation.
IntUnsafeNativeMethods.RestoreDC(new HandleRef(this, hDC), -1);
#if TRACK_HDC
// Note: Winforms may call this method during app exit at which point the DC may have been finalized already causing this assert to popup.
Debug.WriteLine(DbgUtil.StackTraceToStr(String.Format("ret[0]=DC.RestoreHdc(hDc=0x{1:x8})", result, unchecked ((int)this.hDC))));
#endif
Debug.Assert(contextStack != null, "Someone is calling RestoreHdc() before SaveHdc()");
if (contextStack != null)
{
GraphicsState g = (GraphicsState)contextStack.Pop();
hCurrentBmp = g.hBitmap;
hCurrentBrush = g.hBrush;
hCurrentPen = g.hPen;
hCurrentFont = g.hFont;
if (g.font != null && g.font.IsAlive)
{
selectedFont = g.font.Target as WindowsFont;
}
else
{
WindowsFont previousFont = selectedFont;
selectedFont = null;
if (previousFont != null && MeasurementDCInfo.IsMeasurementDC(this))
{
previousFont.Dispose();
}
}
}
#if OPTIMIZED_MEASUREMENTDC
// in this case, GDI will copy back the previously saved font into the DC.
// we dont actually know what the font is in our measurement DC so
// we need to clear it off.
MeasurementDCInfo.ResetIfIsMeasurementDC(hDC);
#endif
}
