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Introduction

Hope you are familiar with Windows PropertyGrid control. I had used this control long time back, but I couldn't get a chance to work with dynamic properties. I thought there will be some methods like GridName.Items.Add() to add items at runtime. But, I had to write some lines of code to accomplish the same. My requirement was simple: I want to display all properties of my object in PropertyGrid, but I don't know the name of properties at design time. I have used CollectionBase, ICustomTypeDescriptor and PropertyDescriptor classes to accomplish the same.

Custom Property

First, I created one CustomProperty class with the following public properties:

• Name
• Value
• ReadOnly
• Visible

The constructor looks like this:

public CustomProperty(string sName, 
          object value, bool bReadOnly, bool bVisible )
{
 this.sName = sName;
 this.objValue = value;
 this.bReadOnly = bReadOnly;
 this.bVisible = bVisible;
}

Custom PropertyDescriptor

Next step is to create a PropertyDescriptor for my class. Derived CustomPropertyDescriptor from PropertyDescriptor class.

public class CustomPropertyDescriptor: PropertyDescriptor
{
 CustomProperty m_Property;
 public CustomPropertyDescriptor(ref CustomProperty myProperty, 
             Attribute [] attrs) :base(myProperty.Name, attrs)
 {
  m_Property = myProperty;
 }
 .....

We have to override all methods of PropertyDescriptor since it is an abstract class.

Custom Class

We will be creating object of this CustomClass for PropertyGrid.SelectedObject.

 public class CustomClass: CollectionBase,ICustomTypeDescriptor
{
  
 public void Add(CustomProperty Value)
 {
  base.List.Add(Value);
 }
  
 public void Remove(string Name)
 {
  foreach(CustomProperty prop in base.List)
  {
   if(prop.Name == Name)
   {
    base.List.Remove(prop);
    return;
   }
  }
 }
  
 public CustomProperty this[int index] 
 {
  get 
  {
   return (CustomProperty)base.List[index];
  }
  set
  {
   base.List[index] = (CustomProperty)value;
  }
 }
.......

Here is the most important method GetProperties, which will called while binding object to PropertyGrid.

 public PropertyDescriptorCollection GetProperties(Attribute[] attributes)
{
 PropertyDescriptor[] newProps = new PropertyDescriptor[this.Count];
 for (int i = 0; i < this.Count; i++)
 {
  CustomProperty  prop = (CustomProperty) this[i];
  newProps[i] = new CustomPropertyDescriptor(ref prop, attributes);
 }
  return new PropertyDescriptorCollection(newProps);
}

How to use CustomClass

CustomClass can be used in any Windows Form having PropertyGrid.

CustomClass myProperties = new CustomClass();
propertyGrid1.SelectedObject = myProperties;
......

CustomProperty myProp = new CustomProperty(txtName.Text,txtValue.Text, 
                           chkReadOnly.Checked,true);
myProperties.Add(myProp);
propertyGrid1.Refresh();

Finally

I hope users can extend my CustomClass and use PropertyGrid control with dynamic properties.

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Labview can use PropertyGrid thanks to your code pcncottin 19:11 30 Jul '08   Hello, Your piece of code just saved my life! I have been trying for several days to make the PropertyGrid control work in LabView. LabView can interact with .NET objects and controls but does not have the ability to create a .NET object required to populate a PropertyGrid. Thanks to your new class, it's not a problem anymore. I will be able to display an arbitrary cluster of data (structure) in a PropertyGrid at runtime. I have not tried to change the attribute yet but it should work as well. Thanks again, good job Pierre Cottin Sign In·View Thread·PermaLink 1.00/5 Datatype sensitve properties harish_somanchi 11:05 22 Mar '07   Hi.. Your code has been a lot of use for me. Thanks a lot. I wanted to know how would u modify the code to have ur property grid sensitive to datatype. I mean, if one of the properties is datetime then i want the propertygrid to treat it as one and not string. I need the datepicker control to be invoked when i click it. Hari Sign In·View Thread·PermaLink There is a small bug inside the code alp ates 5:04 26 Dec '06   I have tried to use this class in a asp.net propertygrid but it failed. It returns real properties instead of the created properties. Here is the reason, there is 2 calling type for getproperties function, the one public PropertyDescriptorCollection GetProperties(Attribute[] attributes) works fine but the other which is used by the asp.net propertygrid public PropertyDescriptorCollection GetProperties() fails to return thr correct property descriptors. So i have changed the code in the asp.net property grid to first function by calling with an empty attribute. But rest works fine. Thank you Sign In·View Thread·PermaLink 5.00/5 Type Lions_italy 22:28 16 Jan '06   Yes will be very nice to set the type of item Sign In·View Thread·PermaLink Is it possible to change [Readonly( )] attribute at runtime? jjohn2005 23:13 6 Dec '05   Hi, I have a property "Color" on my property grid. public Color Color { get { return this.color; } set { this.color = value; } } I would like to apply dynamically the [ReadOnly()] attribute on this property. Is it possible? John J Sign In·View Thread·PermaLink 3.86/5 Re: Is it possible to change [Readonly( )] attribute at runtime? Locusta74 19:40 11 Feb '07   If you're looking to 'undo' or apply a readonly attribute for an object during runtime shown on the propertygrid, you need to create your own propertydescriptor, derived from System.ComponentModel.PropertyDescriptor, and use the following code: public CustomPropertyDescriptor(PropertyDescriptor propertyDescriptor, Attribute[] attribute) : base(propertyDescriptor, attribute) { this.propertyDescriptor = TypeDescriptor.CreateProperty( propertyDescriptor.ComponentType, propertyDescriptor, attribute); } Furthermore, from the class implementing ICustomTypeDescriptor (I used System.ComponentModel.CustomTypeDescriptor), do the following in the GetProperties() method: public override PropertyDescriptorCollection GetProperties(Attribute[] attributes) { ArrayList newProperties = new ArrayList(); PropertyDescriptorCollection properties = TypeDescriptor.GetProperties(component); CustomPropertyDescriptor customPropertyDescriptor; Attribute[] readOnlyAttribute = new Attribute[] { ReadOnlyAttribute.No }; Attribute[] browsableAttribute = new Attribute[] {BrowsableAttribute.No }; foreach (PropertyDescriptor propertyDescriptor in properties) { if (propertyDescriptor.GetValue(component) is IList) { customPropertyDescriptor = new CustomPropertyDescriptor(propertyDescriptor, browsableAttribute); } else { customPropertyDescriptor = new CustomPropertyDescriptor(propertyDescriptor, readOnlyAttribute); } newProperties.Add(customPropertyDescriptor); } return new PropertyDescriptorCollection((PropertyDescriptor[])newProperties.ToArray(typeof(PropertyDescriptor))); } The above code will ignore the ReadOnly attribute by adding a ReadOnly.No attribute on the properties, and hide the properties that are IList based (collections) Sign In·View Thread·PermaLink 2.25/5 Look a little further ByteGhost 12:38 28 Feb '05   See a good article Bending the .NET PropertyGrid to Your Will by Tony Allowatt her on this site This explains a lot of your questions............ Signing Off.... ByteGhost Sign In·View Thread·PermaLink Dynamic list property Poletto 23:23 30 Jan '05   Hi Sreejumon I observed your reply to Damslang gives the answer also my question. Thanks for this. However I will be very greatful to you if you give me a help to solve this drawback. I have modified CustomProperty in order to handle also the type of the property. For example, in case of boolean data, I will have this code: CustomProperty myProp = new CustomProperty(txtCategory.Text, txtHelp.text, typeof(bool), txtName.Text, txtValue.Text, chkReadOnly.Checked,true); The case will be more complex if I want to select a property value from a combolist of data. I image that I should change CustomProperty in order to satisfy this condition: CustomProperty myProp = new CustomProperty(txtCategory.Text, txtHelp.text, typeof(StatesList), txtName.Text, txtValue.Text, chkReadOnly.Checked,true); where StatesList is a class, for example, so made: public class StatesList : System.ComponentModel.StringConverter { string[] _States = {"Alabama", "Alaska", "Arizona", "Arkansas"}; public override System.ComponentModel.TypeConverter.StandardValuesCollection GetStandardValues(ITypeDescriptorContext context) { return new StandardValuesCollection(_States); } public override bool GetStandardValuesSupported(ITypeDescriptorContext context) { return true; } public override bool GetStandardValuesExclusive(ITypeDescriptorContext context) { return true; } } Can you tell me if I have choosen the right way ?. Otherwise can you suggest me the correct approch ? Thanks. Best regards Poletto Sign In·View Thread·PermaLink 3.00/5 Re: Dynamic list property salle78 3:27 24 Nov '08   I was able to solve the issue of adding a "dynamic type" thanks to Stack Overflow: how-to-modify-propertygrid-at-runtime-addremove-property-and-dynamic-typesenums[^] A complete project with the solution can be downloaded here[^] Sign In·View Thread·PermaLink 3.00/5 Attributes damslang 23:25 24 Jan '05   Great work! I m writing a config file editor and this was a great way to dynamically read the xml properties and add them to the propertygrid. Just one question : how could one add description and category attributes to each property? Sign In·View Thread·PermaLink Re: Attributes damslang 0:30 25 Jan '05   ;PDon't worry i've figured it out on my own, quite simple : Added two properties Description and Category in CustomProperty and then in CustomPropertyDescriptor i return m_Property.Description and m_Property.Category Sign In·View Thread·PermaLink 2.00/5 Extending dynamic propertygrid capabilities Poletto 22:56 24 Jan '05   Hi Sreejumon I have visited your sample about dynamic property grid. I am trying to use it in my application, but I find it not completed. For example I need to decide the category where collecting the property and its help-description. Can you give me a help to modify your code ?. Best regards Maurizio Sign In·View Thread·PermaLink 4.22/5 Re: Extending dynamic propertygrid capabilities varad27 22:20 3 Sep '07   Hi Sreejumon, I tried this code sample to create property grid items dynamicall and it works fine. The problem is I am nor longer use EditorAttribute feature of UiTyeEditor .So all my check Boxes and dropdown lists created in property grid is ignored if I use ICustomTypeDescriptor in my class. Can you help me how to use editorattribute feature in Cuatom property creation ? I am new to c# and propertygrid. Cheers, Rajan Rajan Sign In·View Thread·PermaLink 2.14/5

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