c# - Cannot save file after opening it -

i can save file infinitely. can open file infinitely. , can save open file.

however cannot save file after opening it. following error:

a first chance exception of type 'system.runtime.interopservices.externalexception' occurred in system.drawing.dll

additional information: generic error occurred in gdi+.

i tried disposing , temp bitmaps, did not seem work me. location file being opened , saved same place, perhaps maybe problem overwriting file? program breaks @ temp.save

private void opentoolstripmenuitem_click(object sender, eventargs e)         {             //graphics.fromimage(bmap).dispose();             using (graphics g = graphics.fromimage(bmap))             {                  bmap = new bitmap(@"c:\users\nick\final.bmp");                 g.drawimage(bmap, panel1.width, panel1.height);             }             panel1.invalidate();         }  private void savetoolstripmenuitem_click(object sender, eventargs e)         {             graphics g = graphics.fromimage(bmap);             temp =new bitmap(bmap);             //graphics.fromimage(bmap).dispose();             try             {                 g.dispose();                           temp.save(@"c:\users\nick\final.bmp", imageformat.bmp);             }             catch (unauthorizedaccessexception ex)             {                 console.writeline(ex.message); ;             }             catch (system.runtime.interopservices.externalexception ex)             {                 console.writeline(ex.message);             }          } 

you can't overwrite file, because when use new bitmap(path) file loaded in memory , keep open until you're done it, can't overwrite file if it's open.

edit

here how load image memory stream:

// make sure don't dispose of until you're done var memorystream = new memorystream(file.readallbytes(path)); image img = image.fromstream(memorystream);