How do you initialize automatic list properties?

T M Gray

publc class Thing
{
Thing () {}

public List<Foo> MyFoos {get; set;}
}

How do you get the list to be defaulted to an empty list rather than null? Do I need to implement a private backing variable?

Not Active

Either use a backing field and lazy initialization

public class Thing
{
private List m_List;

Thing() { }

public List MyFoos
{
get
{
if(m_List == null)
m_List = new List();

   return m\_List;
 }
 set{ m\_List = value; }

}

or use the constructor

public class Thing
{
Thing()
{
MyFoos = new List();
}

public List MyFoos {get; set;}
}

I know the language. I've read a book. - _Madmatt

Lost User

Or initialize it in the constructor :) --edit What Mark said!

I are Troll :suss:

fjdiewornncalwe

Excellent answer... (Because I do it this way, of course.)

I wasn't, now I am, then I won't be anymore.

T M Gray

Do you have to do it in every constructor? I put it in the default constructor but it doesn't seem to work when I instatiate using a different constructor.

fjdiewornncalwe

You need to append :basename() to the constructor definitions.

public class MySuperAwesomeClass
{
public int AwesomeOne { get; set; }
public int NotAsAwesome { get; set; }
public string UselessCrap { get; set; }

public MySuperAwesomeClass()
{
    AwesomeOne = 42;
    NotAsAwesome = -1;
}

public MySuperAwesomeClass( string someValue ) : base()
{
    UselessCrap = someValue;
}

}

I wasn't, now I am, then I won't be anymore.

T M Gray

Appending :base() doesn't run the default constructor for that class. The debugger never enters the default constructor and all my list properties are still null if I instantiate using a different constructor.

Pete OHanlon

Rather than append :base(), you should use :this() to call the default constructor in the current class. The use of base implies a call to a base class, whereas this refers to the current class.

I have CDO, it's OCD with the letters in the right order; just as they ruddy well should be

Forgive your enemies - it messes with their heads

My blog | My articles | MoXAML PowerToys | Onyx

Pete OHanlon

Not quite. I suspect you're thinking of :this() instead.

I have CDO, it's OCD with the letters in the right order; just as they ruddy well should be

Forgive your enemies - it messes with their heads

My blog | My articles | MoXAML PowerToys | Onyx