Loading image data from xml file.

Question

Hi All. I have the following code that loads data from an xml file. I've done this quite a while back but don't have that code anymore, and this isn't working. (I can successfully write image data to file. But loading it and converting to image object isn't working):

p.Image = Base64ToImage(controlTag.Attributes("Content").First().Value); // i call this on button click.

and...:

public Image Base64ToImage(string base64String)
{
    // Convert Base64 String to byte[]
    byte[] imageBytes = Convert.FromBase64String(base64String);
    MemoryStream ms = new MemoryStream(imageBytes, 0,
      imageBytes.Length);

    // Convert byte[] to Image
    ms.Write(imageBytes, 0, imageBytes.Length);
    Image image = Image.FromStream(ms, true);
    return image;
}

Can somebody please explain why this isn't displaying the converted image on my Form? I don't get any errors at all... The images just don't show up.

Thank you

bael

UPDATE

---

The following code is what's used to write the image data to the xml file:

public string ImageToBase64(Image image, System.Drawing.Imaging.ImageFormat format)
{
    using (MemoryStream ms = new MemoryStream())
    {
        // Convert Image to byte[]
        image.Save(ms, format);
        byte[] imageBytes = ms.ToArray();

        // Convert byte[] to Base64 String
        string base64String = Convert.ToBase64String(imageBytes);
        return base64String;
    }
}

...And this is what loads (well, trys to anyway) the image from the xml file and displays it on the Form:

public Image Base64ToImage(string base64String)
{
    // Convert Base64 String to byte[]
    byte[] imageBytes = Convert.FromBase64String(base64String);
    MemoryStream ms = new MemoryStream(imageBytes);
    return Image.FromStream(ms, true);
}

And here is what the xml file looks like:

<?xml version="1.0" encoding="utf-8"?>
<cs>
  <PictureBox Content="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" LocationX="446" LocationY="125" />
</cs>

---

UPDATE

Here is the code that I use to open/read/process the xml file. Also note that all other controls (such as labels linklabels etc) are properly read from the file and successfully displayed on the Form. It's just the PictureBox's that don't show up:

private void toolStripButton1392_Click(object sender, EventArgs e)
{
    OpenFileDialog o = new OpenFileDialog();

    o.Filter =
        "T Multimedia Format (*.mf)|*.mf|" +
        "Word Document (*.docx)|*.docx|" +
        "PDF Document (*.pdf)|*.pdf|" +
        "Text FIle (*.txt)|*.txt";
    o.Title = "T 11 - Open Document";

    using (o)
    {
        if (o.ShowDialog() == DialogResult.OK)
        {
            foreach (var controlTag in XDocument.Load(o.FileName).Root.Elements())
            {
                var controlType = Type.GetType(string.Format("System.Windows.Forms.{0}, System.Windows.Forms, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089", controlTag.Name.LocalName), false);
                if (controlType == null || !typeof(Control).IsAssignableFrom(controlType))
                {
                    continue;
                }

                var control = (Control)Activator.CreateInstance(controlType);
                control.Text = controlTag.Attributes("Content").First().Value;

                try
                {
                    control.ForeColor = Color.FromArgb(
                        int.Parse(controlTag.Attributes("A").First().Value),
                        int.Parse(controlTag.Attributes("R").First().Value),
                        int.Parse(controlTag.Attributes("G").First().Value),
                        int.Parse(controlTag.Attributes("B").First().Value));

                    Font font = FromString(controlTag.Attributes("Font").First().Value);
                    control.Font = font;
                }
                catch { continue; }

                control.BackColor = Color.Transparent;

                control.MouseDown += new MouseEventHandler(control_MouseDown);
                control.MouseMove += new MouseEventHandler(control_MouseMove);
                control.MouseUp += new MouseEventHandler(control_MouseUp);
                control.MouseClick += new MouseEventHandler(control_MouseClick);
                control.MouseDoubleClick += new MouseEventHandler(control_MouseDoubleClick);

                Type t = control.GetType();
                if (t.Name == "Label")
                {
                    Control c = control;
                    c = control;
                    Label label = (Label)control;
                    label.AutoSize = true;
                    label.Location = new Point(
                        Convert.ToInt32(controlTag.Attributes("LocationX").First().Value),
                        Convert.ToInt32(controlTag.Attributes("LocationY").First().Value));

                    Canvas.Controls.Add(label);

                    // handlers.
                    label.MouseDown += new MouseEventHandler(label_MouseDown);
                    label.MouseMove += new MouseEventHandler(label_MouseMove);
                    label.MouseUp += new MouseEventHandler(label_MouseUp);
                    label.MouseClick += new MouseEventHandler(label_MouseClick);
                    label.MouseDoubleClick += new MouseEventHandler(label_MouseDoubleClick);
                }
                else if (t.Name == "LinkLabel")
                {
                    Control c = control;

                    LinkLabel link = new LinkLabel();
                    link.AutoSize = true;
                    link.Location = new Point(
                        Convert.ToInt32(controlTag.Attributes("LocationX").First().Value),
                        Convert.ToInt32(controlTag.Attributes("LocationY").First().Value));

                    Canvas.Controls.Add(link);

                    // Add handlers.
                    link.MouseDown += new MouseEventHandler(link_MouseDown);
                    link.MouseMove += new MouseEventHandler(link_MouseMove);
                    link.MouseUp += new MouseEventHandler(link_MouseUp);
                    link.MouseClick += new MouseEventHandler(link_MouseClick);
                    link.MouseDoubleClick += new MouseEventHandler(link_MouseDoubleClick);
                }
                else if (t.Name == "PictureBox")
                {
                    Control c = control;
                    c = control;
                    PictureBox p = new PictureBox();

                    p.Image = Base64ToImage(controlTag.Attributes("Content").First().Value);
                    p.InitialImage = Base64ToImage(controlTag.Attributes("Content").First().Value);
                    p.Size = new Size(50, 50);
                    p.Location = new Point(
                        Convert.ToInt32(controlTag.Attributes("LocationX").First().Value),
                        Convert.ToInt32(controlTag.Attributes("LocationY").First().Value));

                    Canvas.Controls.Add(p);

                    // Add handlers.
                    p.MouseDown += new MouseEventHandler(p_MouseDown);
                    p.MouseMove += new MouseEventHandler(p_MouseMove);
                    p.MouseUp += new MouseEventHandler(p_MouseUp);
                    p.MouseClick += new MouseEventHandler(p_MouseClick);
                    p.MouseDoubleClick += new MouseEventHandler(p_MouseDoubleClick);
                }
            }
            this.Text = "T 11 - " + o.FileName;
        }
    }
}

Answer 1

You should reset the position of MemoryStream right after the Write call:

ms.Position = 0;

Calls to Write will increase the position automatically. Consequently, without resetting the position, the stream will already be at the end and Image.FromStream will fail to read from it (it starts reading at the current position).

---

Update

I'm seeing that your Write call is fundamentally unnecessary. You should simply initialize the MemoryStream with the byte[] directly by passing it as the constructor:

byte[] imageBytes = Convert.FromBase64String(base64String);
MemoryStream ms = new MemoryStream(imageBytes);
return Image.FromStream(ms, true);

If this fails, something is probably wrong with the data you're reading from XML.

---

Update:

My test application works with your image:

using System;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Windows.Forms;
using System.Xml.Linq;
class Program
{
    static void Main(string[] args)
    {
        string xml = @"<?xml version=""1.0"" encoding=""utf-8""?>
<cs>
  <PictureBox Content=""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"" LocationX=""446"" LocationY=""125"" />
</cs>";
        var x = XDocument.Parse(xml);
        var s = x.Descendants("PictureBox").First().Attribute("Content").Value;
        var f = new Form();
        PictureBox p = new PictureBox();
        p.Dock = DockStyle.Fill;
        f.Controls.Add(p);
        p.Image = Base64ToImage(s);
        Application.Run(f);
    }

    static Image Base64ToImage(string base64String)
    {
        byte[] imageBytes = Convert.FromBase64String(base64String);
        MemoryStream ms = new MemoryStream(imageBytes);
        return Image.FromStream(ms, true);
    }
}

Check your event handlers, XML load process, and other stuff. This part of code looks fine.