property for list<T> [closed]

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List<T> lst = new L开发者_开发百科ist<T>();

public List<T> List
{
    get { return lst; }
    set { //cod...???????????????????? }
}

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List<T> lst = new List<T>();

public List<T> List
{
    get { return lst; }
    set { lst = value; }
}

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In most cases like this, you do not want a setter, effectively making the list itself read-only. In other words, anybody can change the contents of the list, but you can never give an instance of the object a new list.

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From your comment above it looks like you want the setter to copy all items over, in which case you would do this:

private List<T> lst;

public List<T> List {
    get { return lst; }
    set { lst = new List<T>(value); }
}

But if that's all you want, I would recommend just using an auto property, to wit:

public List<T> MyList { get; set; }

Of course this raises issues of encapsulation, as Gabe pointed out.

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Most often I would recommend that properties of a collection type do not have a public Set so they don't allow changing the actual collection object reference, only modify the collection. Otherwise it can lead to confusing problems if a user saves the reference to the collection and then in another part of the code sets the property to another collection. The first usage then have a reference to something that the class containing the property is not using.

public List<T> List { get; private set;}

public MyClass()
{
    this.List = new List<T>();
}

or, depending on when and how you want to define your collection...

private List<T> list = new List<T>();
public List<T> List { get { return list; } }

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List<T> lst = new List<T>();

public List<T> List
{
    get { return lst; }
    set { lst.AddRange(value); }
}

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Simply encapsulate it using Studio. ;)