static unsafe Bitmap _Capture(RECT r, AWnd w = default, bool usePrintWindow = false, GraphicsPath path = null)
{
//Transfer from screen/window DC to memory DC (does not work without this) and get pixels.
//rejected: parameter includeNonClient (GetWindowDC).
// Nothing good. If in background, captures incorrect caption etc.
// If need nonclient part, better activate window and capture window rectangle from screen.
//FUTURE: if w is DWM-scaled...
using var mb = new AMemoryBitmap(r.Width, r.Height);
if (usePrintWindow && Api.PrintWindow(w, mb.Hdc, Api.PW_CLIENTONLY | (AVersion.MinWin8_1 ? Api.PW_RENDERFULLCONTENT : 0)))
{
//AOutput.Write("PrintWindow OK");
}
else
{
using (var dc = new WindowDC_(w)) {
if (dc.Is0)
{
w.ThrowNoNative("Failed");
}
uint rop = !w.Is0 ? Api.SRCCOPY : Api.SRCCOPY | Api.CAPTUREBLT;
bool ok = Api.BitBlt(mb.Hdc, 0, 0, r.Width, r.Height, dc, r.left, r.top, rop);
Debug.Assert(ok); //the API fails only if a HDC is invalid
}
}
var R = new Bitmap(r.Width, r.Height, PixelFormat.Format32bppRgb);
try {
var bh = new Api.BITMAPINFOHEADER()
{
biSize = sizeof(Api.BITMAPINFOHEADER),
biWidth = r.Width, biHeight = -r.Height, //use -height for top-down
biPlanes = 1, biBitCount = 32,
//biCompression = 0, //BI_RGB
};
var d = R.LockBits(new Rectangle(0, 0, r.Width, r.Height), ImageLockMode.ReadWrite, R.PixelFormat); //tested: fast, no copy
try {
var apiResult = Api.GetDIBits(mb.Hdc, mb.Hbitmap, 0, r.Height, (void *)d.Scan0, &bh, 0); //DIB_RGB_COLORS
if (apiResult != r.Height)
{
throw new AuException("GetDIBits");
}
_SetAlpha(d, r, path);
}
finally { R.UnlockBits(d); } //tested: fast, no copy
return(R);
}
catch { R.Dispose(); throw; }
}
/// <summary>
/// Creates Bitmap from a GDI bitmap.
/// </summary>
/// <param name="hbitmap">GDI bitmap handle. This function makes its copy.</param>
/// <remarks>
/// How this function is different from <see cref="Image.FromHbitmap"/>:
/// 1. Image.FromHbitmap usually creates bottom-up bitmap, which is incompatible with <see cref="Find"/>. This function creates normal top-down bitmap, like <c>new Bitmap(...)</c>, <c>Bitmap.FromFile(...)</c> etc do.
/// 2. This function always creates bitmap of PixelFormat Format32bppRgb.
/// </remarks>
/// <exception cref="AuException">Failed. For example hbitmap is default(IntPtr).</exception>
/// <exception cref="Exception">Exceptions of Bitmap(int, int, PixelFormat) constructor.</exception>
public static unsafe Bitmap BitmapFromHbitmap(IntPtr hbitmap)
{
var bh = new Api.BITMAPINFOHEADER()
{
biSize = sizeof(Api.BITMAPINFOHEADER)
};
using (var dcs = new ScreenDC_(0)) {
if (0 == Api.GetDIBits(dcs, hbitmap, 0, 0, null, &bh, 0))
{
goto ge;
}
int wid = bh.biWidth, hei = bh.biHeight;
if (hei > 0)
{
bh.biHeight = -bh.biHeight;
}
else
{
hei = -hei;
}
bh.biBitCount = 32;
var R = new Bitmap(wid, hei, PixelFormat.Format32bppRgb);
var d = R.LockBits(new Rectangle(0, 0, wid, hei), ImageLockMode.ReadWrite, R.PixelFormat);
bool ok = hei == Api.GetDIBits(dcs, hbitmap, 0, hei, (void *)d.Scan0, &bh, 0);
R.UnlockBits(d);
if (!ok)
{
R.Dispose(); goto ge;
}
return(R);
}
ge:
throw new AuException();
}
