null issue before initializing object

[spif2001]

I have a class like the following. The DataClass2 type is also derived from ASuperObject. public class DataClass1 : ASuperObject { private DataClass2 dataClass2; public DataClass1(){} public DataClass2 MyDataClass2 { get { if(this.dataClass2 == null) this.dataClass2 = DataClass2Holder.Instance.Dummy; return this.dataClass2; } set{this.dataClass2 = value;} } } From a function I fool around with an instance of DataClass1 and at some time I use the MyDataClass2 property, to get the dataClass2 value. The dataClass2 has not been instantiated yet, so the 'if' clause sets the value. Now the function that called the property would like to know, if the 'if' clause was invoked or not (see code below)- can this be done? int localCount = 1; PropertyInfo[] properties = this.GetType().GetProperties(); foreach(PropertyInfo property in properties) { if(property.PropertyType.BaseType == typeof(ASuperObject)) { //***The following call needs to know if the property was null*** ((ASuperObject)property.GetValue(this,null)).nameAddition += localCount+"_"; //Recursive call following ((ASuperObject)property.GetValue(this,null)).InitializeHierarchy(); localCount++; } } (it must be general and not just a bool being set in DataClass1)

[Colin Angus Mackay]

spif2001 wrote: it must be general and not just a bool being set in DataClass1 No - you have encapsulated the dataClass2 member variable and only permit access throught the MyDataClass2 property (which could do anything it liked). As the MyDataClass2 property is designed to always return a DataClass2 object (or one derived from it) then you can never know by what the state of the member variable was before.

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[Robert Rohde]

1. Solution: Dont return a DataClass2 object but a structure with a DataClass2 and a boolean value (would require to change the type of the property). 2. Solution: Instead of making a property make a method like: public DataClass2 GetMyDataClass2(out bool tookedDummyObject) { if(this.dataClass2 == null) { this.dataClass2 = DataClass2Holder.Instance.Dummy; tookedDummyObject = true; } else { tookedDummyObject = false; } return this.dataClass2; } If you still want the property to be present (for other callers who do not need the extra info) it could be implemented like: get { bool notNeeded; return GetMyDataClass2(out notNeeded) }

[spif2001]

Good solutions there, but I have to minimize the code added to the ASuperObject sub-classes. Ended up with a boolean solution after all, namely adding a bool isDummy to the ASuperObject abstract class. Then in my DataClass2Holder(Singleton) i set the bool after the Dummy DataClass2 has been instantiated. Then I don't need to alter the property impl. in DataClass1 and the Dummy becomes semi-invisible. Hope I find a better solution along the way, but for now it will have to do. Thanks for the help you both. -spif2001