public static extern bool GetGUIThreadInfo(uint idThread, ref GUITHREADINFO lpgui);
private void RefreshFakeWnd()
{
if (_refreshing)
{
return;
}
if (!User32.IsWindow(_fakeWindowHandle))
{
return;
}
_refreshing = true;
var ptSrc = new POINT(0, 0);
var ptWinPos = new POINT(this.Left, this.Top);
byte biAlpha = 0xFF;
var stBlend = new BLENDFUNCTION(BlendOp.AC_SRC_OVER, 0, biAlpha, BlendOp.AC_SRC_ALPHA);
IntPtr hDC = User32.GetDC(_fakeWindowHandle);
if (hDC == IntPtr.Zero)
{
_refreshing = false;
Debug.Assert(false, "GetDC failed.");
return;
}
IntPtr hdcMemory = Gdi32.CreateCompatibleDC(hDC);
int nBytesPerLine = ((this.GetWidth() * 32 + 31) & (~31)) >> 3;
var stBmpInfoHeader = new BITMAPINFOHEADER();
stBmpInfoHeader.Init();
stBmpInfoHeader.biWidth = this.GetWidth();
stBmpInfoHeader.biHeight = this.GetHeight();
stBmpInfoHeader.biPlanes = 1;
stBmpInfoHeader.biBitCount = 32;
stBmpInfoHeader.biCompression = CompressionType.BI_RGB;
stBmpInfoHeader.biClrUsed = 0;
stBmpInfoHeader.biSizeImage = (uint)(nBytesPerLine * base.Height);
IntPtr pvBits = IntPtr.Zero;
IntPtr hbmpMem = Gdi32.CreateDIBSection(hDC, ref stBmpInfoHeader
, DIBColorTableIdentifier.DIB_RGB_COLORS, out pvBits, IntPtr.Zero, 0);
Debug.Assert(hbmpMem != IntPtr.Zero, "CreateDIBSection failed.");
if (hbmpMem != null)
{
var hbmpOld = Gdi32.SelectObject(hdcMemory, hbmpMem);
var graphic = Graphics.FromHdcInternal(hdcMemory);
graphic.DrawImage(this.BackgroundImage, 0, 0, GetWidth(), GetHeight());
foreach (Control ctrl in this.Controls)
{
if (!ctrl.Visible)
{
continue;
}
using (var bmp = new Bitmap(ctrl.Width, ctrl.Height))
{
var rect = new Rectangle(0, 0, ctrl.Width, ctrl.Height);
ctrl.DrawToBitmap(bmp, rect);
graphic.DrawImage(bmp, ctrl.Left, ctrl.Top, ctrl.Width, ctrl.Height);
}
}
GUITHREADINFO stGuiThreadInfo = new GUITHREADINFO();
stGuiThreadInfo.Init();
if (User32.GetGUIThreadInfo(Kernel32.GetCurrentThreadId(), ref stGuiThreadInfo))
{
if (User32.IsWindow(stGuiThreadInfo.hwndCaret))
{
int height = stGuiThreadInfo.rcCaret.Bottom - stGuiThreadInfo.rcCaret.Top;
POINT ptCaret = new POINT(stGuiThreadInfo.rcCaret.Left, stGuiThreadInfo.rcCaret.Top);
User32.ClientToScreen(stGuiThreadInfo.hwndCaret, ref ptCaret);
User32.ScreenToClient(this.Handle, ref ptCaret);
graphic.DrawLine(new Pen(new SolidBrush(Color.Black)), ptCaret.X, ptCaret.Y, ptCaret.X, ptCaret.Y + height);
}
}
var szWin = new SIZE(this.GetWidth(), this.GetHeight());
User32.UpdateLayeredWindow(_fakeWindowHandle, hDC, ref ptWinPos, ref szWin, hdcMemory, ref ptSrc, 0, ref stBlend, UpdateLayerWindowParameter.ULW_ALPHA);
graphic.Dispose();
Gdi32.SelectObject(hbmpMem, hbmpOld);
Gdi32.DeleteObject(hbmpMem);
}
Gdi32.DeleteDC(hdcMemory);
Gdi32.DeleteDC(hDC);
_refreshing = false;
}