Bitmap.Save 'A generic error occurred in GDI+'

Question

Hello All,
I was just going to play around by generating some bitmaps programatically.
I started off with this simple example, expecting everything to go smoothly, but have run into a strange error.
The following code is by no means good, just something simple and complete I would expect to work:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
namespace BitmapOutput
    public partial class Form1 : Form
        /// <summary>
        /// The picture i am drawing
        /// </summary>
        System.Drawing.Bitmap myBitmap;
        /// <summary>
        /// Graphics object for drawing
        /// </summary>
        System.Drawing.Graphics myGrafx;
        public Form1()
            InitializeComponent();
            this.myBitmap = new Bitmap(800, 600);
            this.myGrafx =                 System.Drawing.Graphics.FromImage(this.myBitmap);
            this.DrawPicture();
            this.ShowPicture();
            this.SavePicture();
        public void DrawPicture()
            this.myGrafx.DrawEllipse(
                new Pen(System.Drawing.Color.AliceBlue),                 new Rectangle(0, 0, 100, 100));
        public void ShowPicture()
            this.pictureBox1.Image = this.myBitmap;
        public void SavePicture()
            this.myBitmap.Save("Output\\out.bmp" ,                    System.Drawing.Imaging.ImageFormat.Bmp );
This runs fine until the SavePicture(...) function is called.
I get the exception:
"A generic error occurred in GDI+."
at the this.myBitmap.Save(...); line.
Most likely there is some detail that I have overlooked, and I appreciate it if anyone could point out to me what I could do to fix it.
But, I'd like to think that this code would work, it makes sense, and requires little effort, that should be one of the goals of .net
Any help or ideas are greatly appreciated!
P.S. how do I use 'code' tags?

Answer 1

Actually, the fix is to properly dispose of your objects in order.  This is one advantage of C#, with the using() syntax:
// new image with transparent Alpha layer
using (var bitmap = new Bitmap(330, 18, PixelFormat.Format32bppArgb))
using (var graphics = Graphics.FromImage(bitmap))
// add some anti-aliasing
graphics.SmoothingMode = SmoothingMode.AntiAlias;
using (var font = new Font("Arial", 14.0f, GraphicsUnit.Pixel))
using (var brush = new SolidBrush(Color.White))
// draw it
graphics.DrawString(user.Email, font, brush, 0, 0);
// setup the response
Response.Clear();
Response.ContentType = "image/png";
Response.BufferOutput = true;
// write it to the output stream
bitmap.Save(Response.OutputStream, ImageFormat.Png);
Response.Flush();
Notice how I dispose (end the using) of the graphics parameter, before I save it?  You don't have to use the using() statements, just call Dispose() at the end of the scope I show above.
I ran into this problem today on Azure (works locally in the cloud, just an Azure 1.3 thing!), and I saw the link to the blog post above.  That was a good link, as it pointed me in the direction of disposing the graphics earlier.
But, there is no point of increasing hte memory usage of two bitmaps if you dispose of your graphics properly before saving.
http://eduncan911.com