[Mono-list] screen capturing in mono
Eric Morgan
eric at rengeo.com
Wed Feb 28 15:48:42 EST 2007
mmmmmm, open source. I'll give that a shot, thanks!
Are there any license restrictions if I do that? Our code is not open
source, it's a commercial product. Should I just include author and rights
of that code within our source code via comments?
I'm only vaguely familiar with the LGPL or GPL licenses... This may be a
good opportunity to ask about that, but I feel that it should be a separate
thread.
Thanks!
Eric
On 2/28/07, Sebastien Pouliot <sebastien.pouliot at gmail.com> wrote:
>
> Eric,
>
> There's no alternative to p/invoke - even if you used 2.0 you would only
> be calling a method hiding some platform specific p/invoke calls.
>
> Now using 2.0 may not be an option for you, but that doesn't prevent you
> from using CopyFromScreen. Why ? because it's open source :-)
>
> Just create your own library using Mono source code for CopyFromScreen
> (and the code it depends on) or include the source in your own project.
>
> Sebastien
>
> On Wed, 2007-02-28 at 13:27 -0700, Eric Morgan wrote:
> > The problem isn't resizing - I don't have an original bitmap to
> > resize. The problem is that I have a control that I want a screenshot
> > of. So, I'm trying to create a Bitmap from whatever is appearing in
> > the control.
> >
> > I pass the control in, then I call control.CreateGraphics();
> > System.Drawing.Graphics g1 = c.CreateGraphics();
> >
> > Then, with the resulting graphics object, I try to create a new
> > bitmap.
> > Bitmap MyImage = new Bitmap(w, h, g1);
> >
> > The thing is, this bitmap is blank, unless I paste back in that BitBlt
> > code. I can't figure out how to get a new bitmap from a graphics
> > object, without BitBlt().
> >
> > Sebastien - Using 2.0 isn't an option, unfortunately.
> >
> > Is there any alternative from P/Invoking in this case?
> >
> > Thanks for all the help!
> >
> > Eric
> >
> > On 2/28/07, Abe Gillespie <abe.gillespie at gmail.com> wrote:
> > It looks like you're just taking the image and resizing it to
> > show in
> > the dialog. You really should not have to go into native OS
> > libraries
> > to do so. Does this site help?
> >
> > http://www.peterprovost.org/archive/2003/05/29/516.aspx
> >
> > -Abe
> >
> > On 2/28/07, Eric Morgan <eric at rengeo.com> wrote:
> > > I'm not too sure how to get a Bitmap object from a graphics
> > object. From
> > > all I've read, I just hear that you have to deal with device
> > contexts. I'm
> > > not too familiar with it, but BitBlt seems to be the way to
> > do that. What
> > > would I need to do to get that bitmap created with what
> > appears in the
> > > control using 100% .NET so it can run in mono? Here's a
> > snippet of code.
> > >
> > >
> > >
> > [System.Runtime.InteropServices.DllImportAttribute("gdi32.dll")]
> > > private static extern bool BitBlt(
> > > IntPtr hdcDest, // handle to destination DC
> > > int nXDest, // x-coord of destination
> > upper-left corner
> > > int nYDest, // y-coord of destination
> > upper-left corner
> > > int nWidth, // width of destination rectangle
> > > int nHeight, // height of destination rectangle
> > > IntPtr hdcSrc, // handle to source DC
> > > int nXSrc, // x-coordinate of source
> > upper-left corner
> > > int nYSrc, // y-coordinate of source
> > upper-left corner
> > > System.Int32 dwRop // raster operation code
> > > );
> > >
> > >
> > > public static Bitmap PerformCapture(Control c, int
> > maxWidth, int
> > > maxHeight)
> > > {
> > > try
> > > {
> > > int w = c.ClientRectangle.Width;
> > > int h = c.ClientRectangle.Height;
> > >
> > > w = System.Math.Min(w, maxWidth);
> > > h = System.Math.Min(w, maxHeight);
> > >
> > > System.Drawing.Graphics g1 =
> > > c.CreateGraphics();//this.CreateGraphics();
> > > Bitmap MyImage = new Bitmap(w, h, g1);
> > > System.Drawing.Graphics g2 =
> > > System.Drawing.Graphics.FromImage (MyImage);
> > > IntPtr dc1 = g1.GetHdc();
> > > IntPtr dc2 = g2.GetHdc();
> > > BitBlt(dc2, 0, 0, w, h, dc1, 0, 0,
> > 13369376);
> > > g1.ReleaseHdc(dc1);
> > > g2.ReleaseHdc(dc2);
> > >
> > > //Separate dialog to display the image. If I comment out
> > the BitBlt code,
> > > it just appears blank.
> > > Library.Windows.Dialogs.ScreenCaptureDlg
> > > dlg = new
> > > Library.Windows.Dialogs.ScreenCaptureDlg(MyImage);
> > > dlg.ShowDialog();
> > >
> > > return MyImage;
> > > }
> > > catch(Exception error)
> > > {
> > > //our exception handling library.
> > > Library.Common.ErrMsg.Err( error );
> > > throw error;
> > >
> > > }
> > > }
> > >
> > >
> > >
> > > On 2/28/07, Abe Gillespie <abe.gillespie at gmail.com> wrote:
> > > > Are you P/Invoking for performance? Why not just use the
> > GDI .Net API?
> > > >
> > > > -Abe
> > > >
> > > > On 2/28/07, Eric Morgan <eric at rengeo.com> wrote:
> > > > > Hi all,
> > > > >
> > > > > Is there a good way to capture screens or something
> > similar in mono? In
> > > our
> > > > > .NET application, we have custom controls, and we
> > basically create a
> > > > > graphics object from it, make a new bitmap, then do a
> > bitblt to get it
> > > into
> > > > > the bitmap. This requires a P/Invoke into gdi32.dll ,
> > which obviously
> > > blows
> > > > > up in mono. Is there a good way to do this using
> > mono? Some other
> > > library
> > > > > maybe?
> > > > >
> > > > > I've tried installing wine and using the gdi32.dll.so
> > that comes with
> > > it,
> > > > > but I don't know if I'm using it correctly or not. It
> > can find the
> > > library,
> > > > > but it gives a SIGSEGV while trying to execute the
> > bitblt operation.
> > > Seemed
> > > > > like kind of a hack, and I didn't really expect it to
> > work... Do I need
> > > > > other libraries along with the gdi32.dll.so ?
> > > > >
> > > > > Any advice is appreciated. Thanks.
> > > > >
> > > > > Eric Morgan
> > > > > Renegade Geophysics
> > > > > 303-661-0400, x2
> > > > >
> > > > > _______________________________________________
> > > > > Mono-list maillist - Mono-list at lists.ximian.com
> > > > > http://lists.ximian.com/mailman/listinfo/mono-list
> > > > >
> > > > >
> > > >
> > > >
> > >
> > >
> > > _______________________________________________
> > > Mono-list maillist - Mono-list at lists.ximian.com
> > > http://lists.ximian.com/mailman/listinfo/mono-list
> > >
> > >
> >
> >
> > _______________________________________________
> > Mono-list maillist - Mono-list at lists.ximian.com
> > http://lists.ximian.com/mailman/listinfo/mono-list
>
>
>
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