Question

As I understood , The property grid is given an object which it can manipulate by extracting its Properties using reflections.

My problem is that I have a set of Parameters that is determined during run-time , thus I can’t staticly compose a class with properties to represent this set.

I have two idea in mind to solve this problem but both are complex and will probably consume lot of time , infact i will say they are not practical under my time constraints. One is to use Reflection Emit in order to define a class dynamically and the other is to dynamiclly build a C# source file and then compile it using CodeDom.

Can Property grid behave in a different manner( other then extracting the Properties of an object using reflections ) that can suite my problem?

If no do you know any other control that can do the job for me?

I want to say that the reason I went to the property grid from the begining was its ability to provide realy nice Data Retrieval UI for common types.For color you autometically get a palette , For dataTime you automatically have a nice calender. I would like to get those things automatically , If possible.

Answer 1

Yes, PropertyGrid can display things other than just the compile-time properties, by using any of TypeConverter, ICustomTypeDescriptor or TypeDescriptionProvider to provide runtime pseudo-properties. Can you give an example of what your parameters look like? I should be able to provide an example…

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here’s a basic example (everything is string, etc) based on an earlier reply (related but different):

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Windows.Forms;
class PropertyBagPropertyDescriptor : PropertyDescriptor {
    public PropertyBagPropertyDescriptor(string name) : base(name, null) { }
    public override object GetValue(object component) {
        return ((PropertyBag)component)[Name];
    }
    public override void SetValue(object component, object value) {
        ((PropertyBag)component)[Name] = (string)value;
    }
    public override void ResetValue(object component) {
        ((PropertyBag)component)[Name] = null;
    }
    public override bool CanResetValue(object component) {
        return true;
    }
    public override bool ShouldSerializeValue(object component)
    { // *** this controls whether it appears bold or not; you could compare
      // *** to a default value, or the last saved value...
        return ((PropertyBag)component)[Name] != null;
    }
    public override Type PropertyType {
        get { return typeof(string); }
    }
    public override bool IsReadOnly {
        get { return false; }
    }
    public override Type ComponentType {
        get { return typeof(PropertyBag); }
    }
}
[TypeConverter(typeof(PropertyBagConverter))]
class PropertyBag {
    public string[] GetKeys() {
        string[] keys = new string[values.Keys.Count];
        values.Keys.CopyTo(keys, 0);
        Array.Sort(keys);
        return keys;
    }
    private readonly Dictionary<string, string> values
        = new Dictionary<string, string>();
    public string this[string key] {
        get {
            string value;
            values.TryGetValue(key, out value);
            return value;
        }
        set {
            if (value == null) values.Remove(key);
            else values[key] = value;
        }
    }
}
// has the job of (among other things) providing properties to the PropertyGrid
class PropertyBagConverter : TypeConverter {
    public override bool GetPropertiesSupported(ITypeDescriptorContext context) {
        return true; // are we providing custom properties from here?
    }
    public override PropertyDescriptorCollection GetProperties(ITypeDescriptorContext context, object value, System.Attribute[] attributes) {
        // get the pseudo-properties
        PropertyBag bag = (PropertyBag)value;
        string[] keys = bag.GetKeys();
        PropertyDescriptor[] props = Array.ConvertAll(
            keys, key => new PropertyBagPropertyDescriptor(key));
        return new PropertyDescriptorCollection(props, true);
    }
}

static class Program {
    [STAThread]
    static void Main() { // demo form app
        PropertyBag bag = new PropertyBag();
        bag["abc"] = "def";
        bag["ghi"] = "jkl";
        bag["mno"] = "pqr";
        Application.EnableVisualStyles();
        Application.Run(
            new Form {
                Controls = { new PropertyGrid {
                    Dock = DockStyle.Fill,
                    SelectedObject = bag
                }}
            });
    }
}