void CreateGraphicsFromNativeHdc(int width, int height)
{
//3. create original dc from memory dc and prepare background
var orgHdc = MyWin32.CreateCompatibleDC(IntPtr.Zero);
bgBmp = new System.Drawing.Bitmap(width, height, System.Drawing.Imaging.PixelFormat.Format32bppArgb);
hbmp = bgBmp.GetHbitmap();
MyWin32.SelectObject(orgHdc, hbmp);
MyWin32.PatBlt(orgHdc, 0, 0, width, height, MyWin32.WHITENESS);
MyWin32.SetBkMode(orgHdc, MyWin32._SetBkMode_TRANSPARENT);
//4. font
hFont = MyWin32.SelectObject(orgHdc, hFont);
//5. region
hRgn = MyWin32.CreateRectRgn(0, 0, width, height);
MyWin32.SelectObject(orgHdc, hRgn);
//6. create graphics from hdc***
gx = System.Drawing.Graphics.FromHdc(orgHdc);
this.originalHdc = orgHdc;
}