object - c# passing class argument to constructor -

the following codes works is, use reference myproperty class passed in constructor instead of typed references in inline code.

how do this, expected pass ref myproperty have tried fails

i propertyclass able handle myproperty classes i.e. no references myproperty in propertyclass

still learning sorry if have missed obvious !

many help

sarah

propertyclass pc = new propertyclass(!here!);   // pass myproperty class here  pc.settings.add(new myproperty("fred", "monday")); pc.savexml("mytest.xml");     public class myproperty {     [xmlattribute]     public string mypropname { get; set; }     [xmlelement]     public string mypropdata { get; set; }      // default constructor needs parameterless serialisation.     public myproperty()     {     }      public myproperty(string name, string data)     {         mypropname = name;         mypropdata = data;     } }    public class propertyclass {     public list<myproperty> settings { get; set; }      public propertyclass()              // how pass required class here ?     {                                   // public propertyclass( ref myproperty myprop)         settings = new list<myproperty>();     }      public void savexml(string filename)     {         using (filestream stream = new filestream(filename, filemode.create))         {             xmlserializer xml = new xmlserializer(typeof(list<myproperty>), new xmlrootattribute("settings"));              xmlserializernamespaces namespaces = new xmlserializernamespaces();             namespaces.add(string.empty, string.empty);              xml.serialize(stream, settings, namespaces);         }     } } 

i change definition of propertyclass to

public class propertyclass<t> {     public list<t> settings { get; set; }      public propertyclass()     {         settings = new list<t>();     }      public void savexml(string filename)     {         using (filestream stream = new filestream(filename, filemode.create))         {             xmlserializer xml = new xmlserializer(typeof(list<t>), new xmlrootattribute("settings"));              xmlserializernamespaces namespaces = new xmlserializernamespaces();             namespaces.add(string.empty, string.empty);              xml.serialize(stream, settings, namespaces);         }     } } 

the type parameter t specifies type of items in list<t>, can instantiate propertyclass follows

var pc = new propertyclass<myproperty>(); 

or when tired of myproperty can change new propertyclass<foo>() without changing elsewhere.

another nice feature generics can place constraints on type parameter in line declare like:

public class propertyclass<t> t : myclass, imyinterface, new() 

this means t has derived myclass, has implement imyinterface , has have parameterless constructor. (obviously not need add such constraints, can useful in cases).

i want rant little more, sure can play , find uses it.