c# - Fileds to Properties Proxy -

let's imagine have following classes not allowed change:

public class basetype {     public uint32 m_basemember = 1;     public bool m_basememberbool = false; }  public class composedtype {     public composedtype()     {         m_basedata = new basetype();     }     public uint32 m_newmember = 2;       public basetype m_basedata; } 

now want edit data putting in propertygrid. created 2 wrapper classes ( http://msdn.microsoft.com/en-us/magazine/cc163816.aspx )

    public class fieldstopropertiesproxytypedescriptor : icustomtypedescriptor  {     private object _target;      // object described      public fieldstopropertiesproxytypedescriptor(object target)      {          if (target == null)              throw new argumentnullexception("target");          _target = target;      }      public object getproxiedobject()     {         return _target;     }      object icustomtypedescriptor.getpropertyowner(propertydescriptor pd)      {          return _target;          // properties belong target object      }      attributecollection icustomtypedescriptor.getattributes()      {          // gets attributes of target object          return typedescriptor.getattributes(_target, true);     }       string icustomtypedescriptor.getclassname()      {          // gets class name of target object          return typedescriptor.getclassname(_target, true);     }      string icustomtypedescriptor.getcomponentname()     {         return typedescriptor.getcomponentname(_target, true);     }      typeconverter icustomtypedescriptor.getconverter()     {         return typedescriptor.getconverter(_target, true);     }      eventdescriptor icustomtypedescriptor.getdefaultevent()     {         return typedescriptor.getdefaultevent(_target, true);     }      propertydescriptor icustomtypedescriptor.getdefaultproperty()     {         return typedescriptor.getdefaultproperty(_target, true);     }      object icustomtypedescriptor.geteditor(type editorbasetype)     {         return typedescriptor.geteditor(_target, editorbasetype);     }      eventdescriptorcollection icustomtypedescriptor.getevents(attribute[] attributes)     {         return typedescriptor.getevents(_target, attributes);     }      eventdescriptorcollection icustomtypedescriptor.getevents()     {         return typedescriptor.getevents( _target );     }      propertydescriptorcollection icustomtypedescriptor.getproperties()      {         return ((icustomtypedescriptor)this).getproperties(null);      }        propertydescriptorcollection icustomtypedescriptor.getproperties( attribute[] attributes)      {          bool filtering = (attributes != null && attributes.length > 0);          propertydescriptorcollection props = new propertydescriptorcollection(null);         foreach (propertydescriptor prop in typedescriptor.getproperties(_target, attributes, true))          {              props.add(prop);          }         foreach (fieldinfo field in _target.gettype().getfields())          {                          fieldpropertydescriptor fielddesc = new fieldpropertydescriptor(field);             if (!filtering || fielddesc.attributes.contains(attributes))                  props.add(fielddesc);         }                                return props;      }  }  public class fieldpropertydescriptor : propertydescriptor {      private fieldinfo _field;      public fieldpropertydescriptor(fieldinfo field) : base(field.name, (attribute[])field.getcustomattributes(typeof(attribute), true))      {          _field = field;      }       public fieldinfo field      {          { return _field; }      }       public override bool equals(object obj)      {          fieldpropertydescriptor other = obj fieldpropertydescriptor;          return other != null && other._field.equals(_field);      }       public override int gethashcode()      {          return _field.gethashcode();      }       public override bool isreadonly      {          { return false; }      }      public override attributecollection attributes     {                 {             if (_field.fieldtype.isclass || _field.fieldtype.isarray)             {                                    attribute[] expandable = new attribute[1];                 expandable[0] = new expandableobjectattribute();                 return attributecollection.fromexisting(base.attributes, expandable);             }             return base.attributes;         }     }      public override void resetvalue(object component)     {      }       public override bool canresetvalue(object component)      {          return false;      }       public override bool shouldserializevalue(object component)      {          return true;      }       public override type componenttype      {          { return _field.declaringtype; }      }       public override type propertytype      {          { return _field.fieldtype; }      }      public override object getvalue(object component)      {         if (component fieldstopropertiesproxytypedescriptor)         {             fieldstopropertiesproxytypedescriptor proxy = (fieldstopropertiesproxytypedescriptor)component;             return _field.getvalue(proxy.getproxiedobject());          }                      return _field.getvalue(component);      }       public override void setvalue(object component, object value)      {         if (component fieldstopropertiesproxytypedescriptor)         {             fieldstopropertiesproxytypedescriptor proxy = (fieldstopropertiesproxytypedescriptor)component;             _field.setvalue(proxy.getproxiedobject(), value);             onvaluechanged(proxy.getproxiedobject(), eventargs.empty);             return;         }           _field.setvalue(component, value);          onvaluechanged(component, eventargs.empty);      }  } 

i can see , edit 'm_newmember' in propertygrid need wrap access 'm_basedata' via fieldstopropertiesproxytypedescriptor. how achieve this. or there better way wrap fields properties?

you can change attributes of given class @ runtime without changing class. write custom typeconverter , set classes, this:

    typedescriptor.addattributes(typeof(composedtype), new typeconverterattribute(typeof(fieldsexpandableobjectconverter)));     typedescriptor.addattributes(typeof(basetype), new typeconverterattribute(typeof(fieldsexpandableobjectconverter))); 

with following typeconverter (re-using fielddescriptor class):

public class fieldsexpandableobjectconverter : expandableobjectconverter {     public override propertydescriptorcollection getproperties(itypedescriptorcontext context, object value, attribute[] attributes)     {         list<propertydescriptor> properties = new list<propertydescriptor>(base.getproperties(context, value, attributes).oftype<propertydescriptor>());         if (value != null)         {             foreach (fieldinfo field in value.gettype().getfields())             {                 fieldpropertydescriptor fielddesc = new fieldpropertydescriptor(field);                 {                     properties.add(fielddesc);                 }             }         }         return new propertydescriptorcollection(properties.toarray());     } }