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 <[EMAIL PROTECTED]> 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 <[EMAIL PROTECTED]> 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 <[EMAIL PROTECTED]> wrote: > > > Are you P/Invoking for performance? Why not just use the > GDI .Net API? > > > > > > -Abe > > > > > > On 2/28/07, Eric Morgan <[EMAIL PROTECTED]> 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 - [email protected] > > > > http://lists.ximian.com/mailman/listinfo/mono-list > > > > > > > > > > > > > > > > > > > > _______________________________________________ > > Mono-list maillist - [email protected] > > http://lists.ximian.com/mailman/listinfo/mono-list > > > > > > > _______________________________________________ > Mono-list maillist - [email protected] > http://lists.ximian.com/mailman/listinfo/mono-list _______________________________________________ Mono-list maillist - [email protected] http://lists.ximian.com/mailman/listinfo/mono-list
