CopyFromScreen increases Memory Usage

Raysefo

Hi,

I have a windows forms app running on a remote server. When I first start this app, the memory usage on task manager was 9876 KB.This app copies screen shots for every 1 minute. When it starts copying screen shots, the memory usage increases to 23993 KB. How can I avoid memory usage? It seems like memory usage will increase much more.

Best Regards.

Here is my code sample:

... //Get Memory Usage             int memKB = (int)System.Diagnostics.Process.GetCurrentProcess().WorkingSet64 / 1024;               Microsoft.Win32.SystemEvents.SessionSwitch += new 
                Microsoft.Win32.SessionSwitchEventHandler(SystemEvents_SessionSwitch);               if (flag)             {                 String time1 = DateTime.Now.ToString("HH:mm:ss");                   Bitmap b = new Bitmap(ScreenWidth, ScreenHeight);                 g = Graphics.FromImage(b);                 g.CopyFromScreen(Point.Empty, Point.Empty, Screen.PrimaryScreen.Bounds.Size);                 time1 = time1.Replace(':', '_');                   if (flag_Credentials)                 {                     IntPtr token = IntPtr.Zero;                     bool isSuccess = LogonUser("User", "Domain", "Pass", LOGON32_LOGON_NEW_CREDENTIALS, 
                                        LOGON32_PROVIDER_DEFAULT, ref token);                       if (isSuccess)                     {                         using (WindowsImpersonationContext person = new WindowsIdentity(token).Impersonate())                         {                             b.Save(@"\\IP\logs\shot" + name + "_" + time1 + "__" + memKB.ToString() + ".jpg", 
                                        System.Drawing.Imaging.ImageFormat.Jpeg);                                                            g.Dispose();                               person.Undo();                         }                     }                 }                 else                 {                     b.Save(@"\\IP\logs\shot" + name + "_" + time1 + "__" + memKB.ToString() + ".jpg", 
                                        System.Drawing.Imaging.ImageFormat.Jpeg);
                                           g.Dispose();                 }             }
...

4 Replies

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Vulpes14y ago
Accepted answer
I'd see if it stops the memory consumption from continually increasing, if you add these two lines at the end of the outer 'if' statement:

if (flag)
{
// existing code
g = null;
GC.Collect();
}
Vulpes14y ago
It's difficult to know what to make of the Graphics.CopyFromScreen method.

In theory calling the Dispose() method - as you've done here - should release the underlying GDI+ resources and the unmanaged memory which is being used for the screen-shot but it doesn't always seem to - at least not immediately.

However, when you set the Graphics variable to null and force a garbage collection, that does seem to release it even though it should only be cleaning up the relatively modest managed resources!

Incidentally, calling GC.Collect may not be necessary. Setting the variable to null means that the Graphics object will become eligible for garbage collection in due course and you'd normally expect the GC to have cleaned it up within a minute anyway.
Raysefo14y ago
Hi,

I also add your code to some other places and now memory is around 11000 KB
Raysefo14y ago
Hi Vulpes,

When I add the code you suggested, memory consumption was 9980 KB at first and after the first screen shot it increases to 20000 KB then after couple of minutes it was 21400 KB. Seems like stable but I am not sure.