I have been working on an asp.net webapp that draws a blue line on an image of a time-schedule depending on what activity you are doing during the day . Everything works fine when I’m debugging the program on my local machine, however when I moved it to the webserver earlier today, and tried it for real, the blue lines do not appear.
For example, you jog from 9 to 10am, then eat from 10 to 11am, the blue line would draw from 9 to 10 horizontally across the jog section, then draw vertically to the eating section and then draw horizontally to 11:00. I do this on an jpg image of a time-schedule grid, then save and load the new drawn-on image to the image-control on the screen.
Any ideas why this doesn’t work on the webserver?
Bitmap image = new Bitmap(Server.MapPath("~") + "/Assets/img/grid.jpg");
Graphics graphics = Graphics.FromImage(image);
Pen p = new Pen(Color.Blue, 5);
//graphics.drawline(pen, X1, Y1, X2, Y2)
image.Save(Server.MapPath("~") + "/Assets/img/grids/" + id + "newgrid.jpg");
imgGrid.ImageUrl = "~/Assets/img/grids/" + id + "newgrid.jpg";
Drawing API are not supported/guaranteed to work in server environment (this is more theoretical issue, normally work ok) – check out System.Drawing in Windows or ASP.NET services.
Likely you have issues reading or writing files. Add tracing to your code and see if you have any exceptions.