如何用析构函数删除申请的内存？看看我的方法对不对

成员函数调用构造函数
TREENODEPTR CTree::NewNode(int val)
{
CTree *t=new CTree();//调用构造函数
t->treenode.key=val;
t->treenode.left=NULL;
t->treenode.right=NULL;
return t->head;
}
构造函数申请空间
CTree::CTree()
{
treenode.key=-1;
treenode.left=NULL;
treenode.right=NULL;
head=&treenode;
}
析构函数为这样对吗？
CTree::~CTree()
{
delete treenode.key;
delete treenode.left;
delete treenode.right;
delete head;
}