Remove C# attribute of a property dynamically

I have a class with a set of properties As given below.

class ContactInfo
{
    [ReadOnly(true)]
    [Category("Contact Info")]
    public string Mobile { get; set; }

    [Category("Contact Info")]
    public string Name{ get; set; }
}

The objects of this class is being assigned to a property grid, so that the users can update an existing cont开发者_JAVA百科act. you can see that Mobile is marked as ReadOnly.

But, when I want to add an entirely new Contact, I would want the users to be able to edit the contact Mobile also. For that I need to remove the Readonly property dynamically from the Type, before assigning the object to the property grid. Is it possible?

You can not remove the attribute at runtime, but you can use reflection to change the ReadOnly attribute's ReadOnly private backing field to False. Making it the equivalent of [ReadOnly(false)]

See this article for details:

http://codinglight.blogspot.com/2008/10/changing-attribute-parameters-at.html

Edit: fixed link

I have to agree w/ Omu; you're really talking about two classes (view models) in this case, to support your two different views. Something like

CreateContactViewModel and EditContactViewModel

it's not possible at the moment to remove attributes dinamycally (at runtime)

as a suggestion you can do 2 classes: one with the attributes and one without

The CodingLight.com blog moved to blogspot (the above link is broken). See http://codinglight.blogspot.com/2008/10/changing-attribute-parameters-at.html.

Moreover, SysAdmin's followup did not mention the [RefreshProperties(RefreshProperties.All)] attribute that seems to be necessary for an actually-working solution.

Finally, I believe that even David Morton (author of the quoted article) missed one very important thing: if the class (ContactInfo, in SysAdmin's followup example) does not have at least one property with the [ReadOnly] attribute defined at compile time, then when the "isReadOnly" FieldInfo is set to true at runtime the result is that the whole class turns read-only.

I followed up the suggestion by Legenden. Here is what I came up with

class ContactInfo
{
        [ReadOnly(true)]
        [Category("Contact Info")]
        public string Mobile { get; set; }

        [Category("Contact Info")]
        public string Name{ get; set; }

        public void SetMobileEdit(bool allowEdit)
        {
             PropertyDescriptor descriptor =  TypeDescriptor.GetProperties(this.GetType())["Mobile"];

             ReadOnlyAttribute attrib = (ReadOnlyAttribute)descriptor.Attributes[typeof(ReadOnlyAttribute)];

             FieldInfo isReadOnly = attrib.GetType().GetField("isReadOnly", BindingFlags.NonPublic | BindingFlags.Instance);

             isReadOnly.SetValue(attrib, !allowEdit);
        }
}