I wanted to take advantage of the large set of functionality offered by
the framework, so for my latest project I'm using managed C++ with .NET
v2. I'm using the gcnew operator in two different ways, and I'm
confused about the lifetime of objects and whether or not I should be
calling delete. Here are two examples:
ref class SYMBOL : public IComparable
{
public:
// Constructor / destructor
SYMBOL()
{
name = nullptr;
};
~SYMBOL()
{
if (name != nullptr)
{
delete name;
}
}
//Data
String^ name;
UInt32 relativeAddress;
// Methods
virtual Int32 CompareTo(Object^ obj)
{
MODULE^ mod = dynamic_cast<MODULE^>(obj);
return relative.CompareTo(mod->relativeAddress);
}
};
In the example above, the class is used to create a List
(System.Collections.Generic.List) of SYMBOL objects. For each addition
to the list (symbols), I do a gcnew of a SYMBOL object, add pass the
gcnew'ed handle to the List.Add method. I also do a gcnew of a String
object, and assign the gcnew'ed handle to the name member of the SYMBOL
object. As you can see, I am explicitly deleting the String object in
the SYMBOL destructor. Is this correct?
The other case is this:
void PARSER::ReadLogFile(void)
{
FileInfo^ logFileI = gcnew FileInfo(logFilename);
FileStream^ logFileS = logFileI->OpenRead();
logData = gcnew array<Byte>((int)logFileI->Length);
int bytesRead = logFileS->Read(logData, 0, (int)logFileI->Length);
delete logFileI;
// TODO: Add some error checking, mechanism for returning 0-length
array on error
}
As you can see, I'm manually deleting the gcnew'ed FileInfo. Is this
correct?
Sorry if this is a basic question, but the info I've found on the net
is not consistent. In one place I found an "expert" saying that
"objects created with gcnew should never be deleted." However, that
doesn't make sense to me. I understand that after the app exits,
objects on the managed heap will eventually be gc'ed, but to be
completely right about memory management, shouldn't I be deleting
objects that I create?
Thanks,
-Chris
