I am creating desktop recording (screen recording) application using Directshow.NET and C#. I am almost done, application is able to record desktop screen. To paint mouse pointer in recording video I have implemented BufferCB
from SampleGrabber
and with the help of my another post Fliped cursor icon on desktop recording using directshow i am able to paint mouse pointer in correct orientation
Here is my code of BufferCB
:
[System.Security.Permissions.SecurityPermission(
System.Security.Permissions.SecurityAction.LinkDemand, Flags =
System.Security.Permissions.SecurityPermissionFlag.UnmanagedCode)]
int ISampleGrabberCB.BufferCB(double SampleTime, IntPtr pBuffer, int BufferLen)
{
if (!wait)
{
wait = true;
Rectangle imageBounds = new Rectangle(0, 0, m_videoWidth, m_videoHeight);
Bitmap bitmap = new Bitmap(m_videoWidth, m_videoHeight, System.Drawing.Imaging.PixelFormat.Format24bppRgb);
System.Drawing.Imaging.BitmapData bitmapData = bitmap.LockBits(imageBounds, System.Drawing.Imaging.ImageLockMode.ReadWrite, bitmap.PixelFormat);
IntPtr ptr = bitmapData.Scan0;
bitmap.UnlockBits(bitmapData);
CopyMemory(ptr, pBuffer, (uint)BufferLen);
bitmap.RotateFlip(System.Drawing.RotateFlipType.RotateNoneFlipY);
using (Graphics g = Graphics.FromImage(bitmap))
{
CURSORINFO cursorInfo;
cursorInfo.cbSize = Marshal.SizeOf(typeof(CURSORINFO));
if (GetCursorInfo(out cursorInfo) && cursorInfo.flags == CURSOR_SHOWING)
{
IntPtr iconPointer = CopyIcon(cursorInfo.hCursor);
ICONINFO iconInfo;
int iconX, iconY;
if (GetIconInfo(iconPointer, out iconInfo))
{
// calculate the correct position of the cursor
iconX = cursorInfo.ptScreenPos.x - ((int)iconInfo.xHotspot);
iconY = cursorInfo.ptScreenPos.y - ((int)iconInfo.yHotspot);
//GETTING ARGUMENTEXCEPTION AT BELOW LINE
IntPtr hdc = g.GetHdc();
DrawIcon(hdc, iconX, iconY, cursorInfo.hCursor);
g.ReleaseHdc(hdc);
}
}
g.DrawImage(companylogo, m_videoWidth - 100 , 20);
}
bitmap.RotateFlip(System.Drawing.RotateFlipType.RotateNoneFlipY);
bitmapData = bitmap.LockBits(imageBounds, System.Drawing.Imaging.ImageLockMode.ReadWrite, bitmap.PixelFormat);
ptr = bitmapData.Scan0;
bitmap.UnlockBits(bitmapData);
CopyMemory(pBuffer, ptr, (uint)BufferLen);
bitmap.Dispose();
wait = false;
}
return 0;
}
Mouse pointer is getting paint on video but after some time of recording I am getting ArgumentException
"Parameter is not valid."
at line of code IntPtr hdc = g.GetHdc();
Can anyone help me put to solve this?
StackTrace:
at System.Drawing.Graphics.GetHdc()
Look at the answer in this question. They discuss the same error message.