c# - paint program not saving edited picture -

am developing paint application in c# , vs2010

the start-up interface blank picturebox , did mousedown , mousemove event handler brush tool paint , works fine

when try save new picture (after painting on blank picturebox) enter file , , it's blank picture.

the problem code not saving effects.

why?

mousedown event handler

private void mousedown(object sender, mouseeventargs e)     {         if (currentfunction == "drawfree")         {             if (e.button == mousebuttons.left)                 releaseflag = true;             startpoint = e.location;         }     } 

mousemove event handler

 private void mousemove(object sender, mouseeventargs e)     {         if (currentfunction == "drawfree")         {             if (releaseflag)             {                 endpoint = e.location;                 g = picturebox1.creategraphics();                 g.drawline(p, startpoint, endpoint);             }             startpoint = endpoint;         }      } 

save code

 private void savephototoolstripmenuitem_click(object sender, eventargs e)     {          using (bitmap bmp = new bitmap(picturebox1.clientsize.width,                             picturebox1.clientsize.height))         {             using (graphics g = graphics.fromimage(bmp))             {                 image yourimage = picturebox1.image;                 bitmap yourbitmap = new bitmap(yourimage);                  g.drawimage(yourbitmap,                             new rectangle(0, 0, bmp.width, bmp.height),                             new rectangle(0, 0, yourimage.width, yourimage.height),                             graphicsunit.pixel);             }             bmp.save(@"d:\yourfile.png", imageformat.png);         }     } 

since bitmapped "yourbitmap" yourimage, try replacing bmp.save yourbitmap.save

    yourbitmap.image.save(@"d:\yourfile.png", imageformat.png);