Screen Capture Problem?

Question

Hi I am screen capturing as follows: Bitmap b = new Bitmap (ScreenWidth ScreenHeight); g = Graphics . FromImage(b); g . CopyFromScreen( Point . Empty Point . Empty Screen . PrimaryScreen . Bounds . Size); b . Save( @S:\shot + i . ToString() + .jpg  System . Drawing . Imaging . ImageFormat . Jpeg); i = i + 1 ; The problem is when I lock the computer it gives The handle is invalid exception for the line below: g . CopyFromScreen( Point . Empty Point . Empty Screen . PrimaryScreen . Bounds . Size); How can I fix this? Best Regards.

Vulpes · Answer

It'll tell you when the session has been locked and so it's not safe to call Graphics.CopyFromScreen. A cruder way would be to simply place the code in a 'try' block and catch (and swallow) the exception if the desktop is locked.

Raysefo · Answer

thanks Vulpes

Raysefo · Answer

I hope this will work Microsoft . Win32 . SystemEvents . SessionSwitch += new Microsoft . Win32 . SessionSwitchEventHandler ( SystemEvents_SessionSwitch ); void SystemEvents_SessionSwitch ( object sender  Microsoft . Win32 . SessionSwitchEventArgs e ) { if ( e . Reason == SessionSwitchReason . SessionLock ) { //I left my desk } else if ( e . Reason == SessionSwitchReason . SessionUnlock ) { //I returned to my desk } }