Is it possible to embed metadata within Winform or control at runtime ?

Question

MS Access and VB has Tag property for form and control where you can store at runtime and persist with the app. Is there something equivalent in .NET ?

Answer 1

Most of the UI controls in .NET do have a .Tag property that can be used for the same purpose.

However, if you need additional functionality, you can make a class which inherits from the base control (i.e. you could make a class called SpecialPictureBox that inherits from PictureBox and adds additional fields), and use it in your Windows Forms just as you could use a PictureBox.

Answer 2

System.Windows.Forms.Control.Tag

Answer 3

There is a Tag property in Windows Forms, but it is not persisted.

The pattern I use is to create a class called Preferences (has properties for each piece of information I want to persist), which is then managed with a PreferencesManager class like this one:

    public class PreferencesManager
{
    static private string dataPath = null;
    static public string DataPath
    {
        get
        {
            if (dataPath == null)
            {
                string baseFolder = System.Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);
                dataPath = Path.Combine(baseFolder, @"MY_APP_NAME");

                if (!Directory.Exists(dataPath))
                {
                    Directory.CreateDirectory(dataPath);
                }
            }

            return dataPath;
        }
    }

    /// <summary>
    /// Saves the specified preferences.
    /// </summary>
    /// <param name="pref">The preferences.</param>
    static public void Save(Preferences pref)
    {
        // Create file to save the data to

        string fn = "Preferences.xml";
        string path = Path.Combine(DataPath, fn);
        using (FileStream fs = new FileStream(path, FileMode.Create))
        {

            // Create an XmlSerializer object to perform the serialization
            XmlSerializer xs = new XmlSerializer(typeof(Preferences));

            // Use the XmlSerializer object to serialize the data to the file
            xs.Serialize(fs, pref);
        }
    }

    static public Preferences Load()
    {
        Preferences ret = null;
        string path = string.Empty;

        try
        {
            // Open file to read the data from

            string fn = "Preferences.xml";
            path = Path.Combine(DataPath, fn);
            using (FileStream fs = new FileStream(path, FileMode.Open))
            {

                // Create an XmlSerializer object to perform the deserialization
                XmlSerializer xs = new XmlSerializer(typeof(Preferences));

                // Use the XmlSerializer object to deserialize the data from the file
                ret = (Preferences)xs.Deserialize(fs);
            }
        }
        catch (System.IO.DirectoryNotFoundException)
        {
            throw new Exception("Could not find the data directory '" + DataPath + "'");
        }
        catch (InvalidOperationException)
        {
            return new Preferences();
        }
        catch (System.IO.FileNotFoundException)
        {
            return new Preferences();
        }

        return ret;
    }

}