Question

from static function we can create a instance but we can not access any non-static data member….why.

public static DropoffType DROP_BOX
        {
            get
            {
                DropoffType tempType = new DropoffType();
                tempType.DropoffTypeSelected = _DROP_BOX;
                y=11; // compile time error
                return tempType;
            }
        }

from the above code we can see that instance can be created from property but when we are trying to access any non-static data member then i am getting complile time error. can any one explain the reason in detail that why instance can be created from any where but non-static data member can’t be access from static function.

Answer 1

If y is an instance field, you can’t access it without telling it which object you mean. For an instance member, there is an implicit this., i.e. this.y.

Just add:

tempType.y = 11;

The problem is, you could have any number of variables and objects kicking around. And even for an instance method you often have to disambiguate, i.e.

public int CompareTo(Foo other) {
    return string.Compare(this.Bar, other.Bar);
}

(in the above the this. is not strictly needed, but helps the reader IMO; the other. is entirely necessary)