private Gdi32.HBITMAP GetCompatibleBitmap(Bitmap bm)
{
using var screenDC = User32.GetDcScope.ScreenDC;
// GDI+ returns a DIBSECTION based HBITMAP. The clipboard deals well
// only with bitmaps created using CreateCompatibleBitmap(). So, we
// convert the DIBSECTION into a compatible bitmap.
Gdi32.HBITMAP hBitmap = bm.GetHBITMAP();
// Create a compatible DC to render the source bitmap.
using var sourceDC = new Gdi32.CreateDcScope(screenDC);
using var sourceBitmapSelection = new Gdi32.SelectObjectScope(sourceDC, hBitmap);
// Create a compatible DC and a new compatible bitmap.
using var destinationDC = new Gdi32.CreateDcScope(screenDC);
Gdi32.HBITMAP bitmap = Gdi32.CreateCompatibleBitmap(screenDC, bm.Size.Width, bm.Size.Height);
// Select the new bitmap into a compatible DC and render the blt the original bitmap.
using var destinationBitmapSelection = new Gdi32.SelectObjectScope(destinationDC, bitmap);
Gdi32.BitBlt(
destinationDC,
0,
0,
bm.Size.Width,
bm.Size.Height,
sourceDC,
0,
0,
Gdi32.ROP.SRCCOPY);
return(bitmap);
}
// this DC is cached and should only be deleted on Dispose or when the size changes.
public Gdi32.HDC GetCachedItemDC(Gdi32.HDC toolStripHDC, Size bitmapSize)
{
if (_cachedHDCSize.Width < bitmapSize.Width ||
_cachedHDCSize.Height < bitmapSize.Height)
{
if (_cachedItemHDC.IsNull)
{
// Create a new DC - we don't have one yet.
_cachedItemHDC = Gdi32.CreateCompatibleDC(toolStripHDC);
}
// Create compatible bitmap with the correct size.
_cachedItemBitmap = Gdi32.CreateCompatibleBitmap(toolStripHDC, bitmapSize.Width, bitmapSize.Height);
Gdi32.HGDIOBJ oldBitmap = Gdi32.SelectObject(_cachedItemHDC, _cachedItemBitmap);
// Delete the old bitmap
if (!oldBitmap.IsNull)
{
Gdi32.DeleteObject(oldBitmap);
}
// remember what size we created.
_cachedHDCSize = bitmapSize;
}
return(_cachedItemHDC);
}
private unsafe void CreateDitherBrush()
{
Debug.Assert(_hbrushDither.IsNull, "Brush should not be recreated.");
short *patternBits = stackalloc short[]
{
unchecked ((short)0xAAAA),
unchecked ((short)0x5555),
unchecked ((short)0xAAAA),
unchecked ((short)0x5555),
unchecked ((short)0xAAAA),
unchecked ((short)0x5555),
unchecked ((short)0xAAAA),
unchecked ((short)0x5555)
};
Gdi32.HBITMAP hbitmapTemp = Gdi32.CreateBitmap(8, 8, 1, 1, patternBits);
Debug.Assert(
!hbitmapTemp.IsNull,
"could not create dither bitmap. Page selector UI will not be correct");
if (!hbitmapTemp.IsNull)
{
_hbrushDither = Gdi32.CreatePatternBrush(hbitmapTemp);
Debug.Assert(
!_hbrushDither.IsNull,
"Unable to created dithered brush. Page selector UI will not be correct");
Gdi32.DeleteObject(hbitmapTemp);
}
}
public static int Add(IHandle himl, Gdi32.HBITMAP hbmImage, Gdi32.HBITMAP hbmMask)
{
int result = Add(himl.Handle, hbmImage, hbmMask);
GC.KeepAlive(himl);
return(result);
}
public void Dispose()
{
if (!hbmMask.IsNull)
{
Gdi32.DeleteObject(hbmMask);
hbmMask = default;
}
if (!hbmColor.IsNull)
{
Gdi32.DeleteObject(hbmColor);
hbmColor = default;
}
}
public void Dispose()
{
if (!_cachedItemHDC.IsNull)
{
if (!_cachedItemBitmap.IsNull)
{
Gdi32.DeleteObject(_cachedItemBitmap);
}
// delete the DC itself.
Gdi32.DeleteDC(_cachedItemHDC);
}
_cachedItemHDC = default;
_cachedItemBitmap = default;
_cachedHDCSize = Size.Empty;
GC.SuppressFinalize(this);
}
public static extern int Add(IntPtr himl, Gdi32.HBITMAP hbmImage, Gdi32.HBITMAP hbmMask);
public static partial int Add(IntPtr himl, Gdi32.HBITMAP hbmImage, Gdi32.HBITMAP hbmMask);
