The document discusses various .NET collections classes in C++/CLI including LinkedList, List, Stack, Queue, Dictionary, SortedDictionary, ArrayList and how to use them. It provides examples of initializing the collections, adding and retrieving elements, and using foreach loops. It also covers potential errors like not initializing objects before adding them to collections, using invalid indexes, and type casting issues when retrieving elements.

1. C++.NET
Windows Forms Course
L07 –Collections
Mohammad Shaker
mohammadshakergtr.wordpress.com
C++.NET Windows Forms Course
@ZGTRShaker

2. Welcome!

3. Collections?

4. Collections Generic
generic?

5. Class
Comparer<T>
Description
Provides a base class for implementations of
the IComparer<T>generic interface.
Dictionary<TKey, TValue>
Dictionary<TKey,
TValue>::KeyCollection
Dictionary<TKey,
TValue>::ValueCollection
EqualityComparer<T>
Represents a collection of keys and values.
Represents the collection of keys in a Dictionary<TKey,
TValue>. This class cannot be inherited.
HashSet<T>
KeyedByTypeCollection<TItem>
KeyNotFoundException
Represents a set of values.
Provides a collection whose items are types that serve as keys.
The exception that is thrown when the key specified for
accessing an element in a collection does not match any key in
the collection.
LinkedList<T>
LinkedListNode<T>
Represents a doubly linked list.
Represents a node in a LinkedList<T>. This class cannot be
inherited.
List<T>
Represents a strongly typed list of objects that can be
accessed by index. Provides methods to search, sort, and
manipulate lists.
Represents a first-in, first-out collection of objects.
Queue<T>
Represents the collection of values in a Dictionary<TKey,
TValue>. This class cannot be inherited.
Provides a base class for implementations of
theIEqualityComparer<T> generic interface.

6. SortedDictionary<TKey, TValue>
Represents a collection of key/value pairs that are sorted on
the key.
SortedDictionary<TKey,
TValue>::KeyCollection
Represents the collection of keys in a SortedDictionary<TKey,
TValue>. This class cannot be inherited.
SortedDictionary<TKey,
TValue>::ValueCollection
Represents the collection of values in
a SortedDictionary<TKey, TValue>. This class cannot be
inherited
SortedList<TKey, TValue>
Represents a collection of key/value pairs that are sorted by
key based on the associated IComparer<T> implementation.
SortedSet<T>
Represents a collection of objects that is maintained in sorted
order.
Represents a variable size last-in-first-out (LIFO) collection of
instances of the same arbitrary type.
Stack<T>
SynchronizedCollection<T>
Provides a thread-safe collection that contains objects of a
type specified by the generic parameter as elements.
SynchronizedKeyedCollection<K, T>
Provides a thread-safe collection that contains objects of a
type specified by a generic parameter and that are grouped by
keys.
SynchronizedReadOnlyCollection<T>
Provides a thread-safe, read-only collection that contains
objects of a type specified by the generic parameter as
elements.

7. Peak on Collections
private : System::Collections::Generic::LinkedList <String ^> ^MyStrList ;
private : System::Collections::Generic::List<TextBox ^> ^List ;
private : System::Collections::Generic::Stack <String ^> ^ MyStack;
private : System::Collections::ArrayList ^MyArrayList ;

8. Peak on Collections
private : System::Collections::Generic::Stack < String ^> ^MyStack;
private: System::Void Form1_Load(System::Object^ sender, System::EventArgs^ e)
{
MyStack = gcnew System::Collections::Generic::Stack < String ^>;
}

9. Peak on Collections
• Let’s have the following!
private : System::Collections::Generic::LinkedList <Button^> ^MyList;
private: System::Void Form1_Load(System::Object^ sender, System::EventArgs^ e)
{
MyList = gcnew System::Collections::Generic:: LinkedList <Button ^>;
}

11. Peak on Collections
private : System::Collections::Generic::LinkedList < String ^> ^MyList;
private: System::Void Form1_Load(System::Object^ sender, System::EventArgs^
e)
{
MyList = gcnew System::Collections::Generic::LinkedList < String ^>;
}
private: System::Void button1_Click_1(System::Object^
System::EventArgs^ e)
{
MyList->AddLast(“MeMe");
MyList->AddLast(“MeMa");
}
sender,

12. Peak on Collections
• What’s wrong?
private : System::Collections::Generic::LinkedList < String ^> ^MyList;
private: System::Void button1_Click_1(System::Object^
System::EventArgs^ e)
{
MyList->AddLast(“MeMe");
MyList->AddLast(“MeMa");
}
Runtime error. the LinkedList is still NULL
sender,

13. Peak on Collections
• “for each” loop
private: System::Void button1_Click_1(System::Object^ sender,
System::EventArgs^ e)
{
for each (String ^str in MyList)
{
textBox1->Text += str + Environment::NewLine ;
}
}

14. private : System::Collections::Generic::LinkedList < String ^> ^MyList;
private: System::Void Form1_Load(System::Object^ sender, System::EventArgs^
e)
{
MyList = gcnew System::Collections::Generic::LinkedList < String ^>;
}
private: System::Void button1_Click_1(System::Object^
System::EventArgs^ e)
{
MyList->AddLast(textBox1->Text);
}
sender,
private: System::Void button1_Click_2(System::Object^ sender,
System::EventArgs^ e)
{
for each (String ^str in MyList)
{
textBox1->Text += str + Environment::NewLine ;
}
}

15. private : System::Collections::Generic::LinkedList < Button^> ^MyList;
private: System::Void Form1_Load(System::Object^ sender, System::EventArgs^
e)
{
MyList = gcnew System::Collections::Generic::LinkedList < Button ^>;
}
private: System::Void button1_Click_1(System::Object^
System::EventArgs^ e)
{
Button ^B1 = gcnew Button ;
MyList->AddLast(B1);
}
sender,
private: System::Void button1_Click_2(System::Object^ sender,
System::EventArgs^ e)
{
static int Counter = 1 ;
for each (Button ^B in MyList)
{
B->Text = “Button” + Counter.ToString();
B->Height = 30 ; B->Width = 50 ;
Counter++ ;
}
}

16. Peak on Collections
• Needs to be static?
private: System::Void button1_Click_2(System::Object^ sender,
System::EventArgs^ e)
{
int Counter = 1 ;
for each (Button ^B in MyList)
{
B->Text = “Button” + Counter.ToString();
B->Height = 30 ; B->Width = 50 ;
Counter++ ;
}
}

17. Peak on Collections - List
private: System::Collections::Generic::List<String^> ^MyList ;
private: System::Void Form1_Load(System::Object^ sender,
System::EventArgs^ e)
{
MyList = gcnew
System::Collections::Generic::List<String^> (4) ;
MyList->Add("Z") ;
MyList->Add("G") ;
MyList->Add("T") ;
MyList->Add("R") ;
}
private: System::Void button1_Click_1(System::Object^
sender, System::EventArgs^ e)
{
for each (String ^str in MyList)
{
textBox1->Text += str + " " ;
}
}

18. List

19. List
private: System::Collections::Generic::List<String^> ^MyList ;
private: System::Void Form1_Load(System::Object^ sender,
System::EventArgs^ e)
{
MyList = gcnew System::Collections::Generic::List<String^> (4) ;
MyList->Add("Z") ;
MyList->Add("G") ;
MyList->Add("T") ;
MyList->Add("R") ;
}
private: System::Void button1_Click_1(System::Object^ sender,
System::EventArgs^ e)
{
for(int i=0; i<4 ; i++)
{
textBox1->Text += MyList[i] + " ";
}
}

20. List

21. List
private: System::Collections::Generic::List<String^> ^MyList ;
private: System::Void Form1_Load(System::Object^ sender,
System::EventArgs^ e)
{
MyList = gcnew
System::Collections::Generic::List<String^> (4) ;
MyList[0] = “Z” ;
MyList[1] = “G” ;
MyList[2] = “T” ;
MyList[3] = “R” ;
}
private: System::Void button1_Click_1(System::Object^
sender, System::EventArgs^ e)
{
for(int i=0; i<4 ; i++)
{
textBox1->Text += MyList[i] + " ";
}
}

22. Peak on Collections – ArrayList
private: System::Collections::ArrayList ^MyArrayList ;
private: System::Void Form1_Load(System::Object^ sender,
System::EventArgs^ e)
{
MyArrayList = gcnew System::Collections::ArrayList (4) ;
static int Counter = 0 ;
Button ^B1 = gcnew Button ;
TextBox ^T1 ;
// Not initialized
String ^S = "ZGTR";
int i ;
// Not initialized
MyArrayList->Add(B1) ;
MyArrayList->Add(T1) ;
MyArrayList->Add(S) ;
MyArrayList->Add(i) ;
}
Everything is good

23. Peak on Collections – ArrayList
private: System::Collections::ArrayList ^MyArrayList ;
private: System::Void Form1_Load(System::Object^ sender,
System::EventArgs^ e)
{
MyArrayList = gcnew System::Collections::ArrayList (4) ;
static int Counter = 0 ;
Button ^B1,^B2= gcnew Button ;
TextBox ^T1 ;
String ^S = "ZGTR";
int i ;
MyArrayList->Add(B1) ;
MyArrayList->Add(T1) ;
MyArrayList->Add(S) ;
MyArrayList->Add(i) ;
MyArrayList[0] = B2 ;
MyArrayList[3] = 6 ;
}
Everything is good

24. Peak on Collections – ArrayList
private: System::Collections::ArrayList ^MyArrayList ;
private: System::Void Form1_Load(System::Object^ sender,
System::EventArgs^ e)
{
MyArrayList = gcnew System::Collections::ArrayList (4) ;
static int Counter = 0 ;
Button ^B1,^B2= gcnew Button ;
TextBox ^T1 ;
String ^S = "ZGTR";
int i ;
MyArrayList->Add(B1) ;
MyArrayList->Add(T1) ;
MyArrayList->Add(S) ;
MyArrayList->Add(i) ;
MyArrayList[0] = B2 ;
MyArrayList[3] = B2 ; // Here!
}
Everything is good

25. Peak on Collections – ArrayList
private: System::Collections::ArrayList ^MyArrayList ;
private: System::Void Form1_Load(System::Object^ sender,
System::EventArgs^ e)
{
MyArrayList = gcnew System::Collections::ArrayList (4) ;
static int Counter = 0 ;
Button ^B1,^B2= gcnew Button ;
TextBox ^T1 ;
String ^S = "ZGTR";
int i ;
MyArrayList->Add(B1) ;
MyArrayList->Add(T1) ;
MyArrayList->Add(S) ;
MyArrayList->Add(i) ;
MyArrayList[0] = 6;
// Here!
MyArrayList[3] = B2 ; // Here!
}
Everything is good

26. Peak on Collections – ArrayList
private: System::Collections::ArrayList ^MyArrayList ;
private: System::Void Form1_Load(System::Object^ sender,
System::EventArgs^ e)
{
MyArrayList = gcnew System::Collections::ArrayList (4) ;
static int Counter = 0 ;
Button ^B1,^B2= gcnew Button ;
TextBox ^T1 ;
String ^S = "ZGTR";
int i ;
B1->Height = 50 ;
MyArrayList->Add(B1) ;
MyArrayList->Add(T1) ;
MyArrayList->Add(S) ;
MyArrayList->Add(i) ;
MyArrayList[0] = B2 ;
MyArrayList[3] = 6 ;
}
Compiler error. No new for Button1

27. Peak on Collections – ArrayList
private: System::Collections::ArrayList ^MyArrayList ;
private: System::Void Form1_Load(System::Object^ sender,
System::EventArgs^ e)
{
MyArrayList = gcnew System::Collections::ArrayList (4) ;
static int Counter = 0 ;
Button ^B1,^B2= gcnew Button ;
B1 = gcnew Button ;
TextBox ^T1 ;
String ^S = "ZGTR";
int i ;
B1->Height = 50 ;
MyArrayList->Add(B1) ;
MyArrayList->Add(T1) ;
MyArrayList->Add(S) ;
MyArrayList->Add(i) ;
MyArrayList[0] = B2 ;
MyArrayList[3] = 6 ;
}
Everything is good

28. Peak on Collections – ArrayList
private: System::Collections::ArrayList ^MyArrayList ;
private: System::Void Form1_Load(System::Object^ sender,
System::EventArgs^ e)
{
MyArrayList = gcnew System::Collections::ArrayList (4) ;
static int Counter = 0 ;
Button ^B1,^B2= gcnew Button ;
B1 = gcnew Button ;
TextBox ^T1 ;
String ^S = "ZGTR";
int i ;
B1->Height = 50 ;
MyArrayList->Add(B1) ;
MyArrayList->Add(T1) ;
MyArrayList->Add(S) ;
MyArrayList->Add(i) ;
MyArrayList[0] = B2 ;
MyArrayList[4] = 6 ;
}
Compiler error. index = 4! Wrong!

29. Peak on Collections – ArrayList
private: System::Collections::ArrayList ^MyArrayList ;
private: System::Void Form1_Load(System::Object^ sender,
System::EventArgs^ e)
{
MyArrayList = gcnew System::Collections::ArrayList (4) ;
static int Counter = 0 ;
Button ^B1,^B2= gcnew Button ;
B1 = gcnew Button ;
TextBox ^T1 ;
String ^S = "ZGTR";
int i ;
B1->Height = 50 ;
MyArrayList->Add(B1) ;
MyArrayList->Add(T1) ;
MyArrayList->Add(S) ;
MyArrayList->Add(i) ;
B2 = MyArrayList[0] ; // 1
MyArrayList[3] = 6 ;
}
Compiler error. object^ and Button^ in 1

30. Peak on Collections – ArrayList
private: System::Collections::ArrayList ^MyArrayList ;
private: System::Void Form1_Load(System::Object^ sender,
System::EventArgs^ e)
{
MyArrayList = gcnew System::Collections::ArrayList (4) ;
static int Counter = 0 ;
Button ^B1 = gcnew Button ;
TextBox ^T1 ;
String ^S = "ZGTR";
int i ;
MyArrayList->Add(B1) ;
MyArrayList->Add(T1) ;
MyArrayList->Add(S) ;
MyArrayList->Add(i) ;
}
Everything is good

31. Peak on Collections – ArrayList
private: System::Collections::ArrayList ^MyArrayList ;
private: System::Void Form1_Load(System::Object^ sender,
System::EventArgs^ e)
{
MyArrayList = gcnew System::Collections::ArrayList (4) ;
static int Counter = 0 ;
Button ^B1 = gcnew Button ;
TextBox ^T1 ;
String ^S = "ZGTR";
int i ;
MyArrayList->Add(B1) ;
MyArrayList->Add(T1) ;
MyArrayList->Add(S) ;
MyArrayList->Add(i) ;
}
private: System::Void button1_Click_1(System::Object^
System::EventArgs^ e)
{
textBox1->Text =MyArrayList[0] ->Height ;
}
Compile error
sender,

32. Peak on Collections – ArrayList
private: System::Collections::ArrayList ^MyArrayList ;
private: System::Void Form1_Load(System::Object^ sender,
System::EventArgs^ e)
{
MyArrayList = gcnew System::Collections::ArrayList (4) ;
static int Counter = 0 ;
Button ^B1 = gcnew Button ;
TextBox ^T1 ;
String ^S = "ZGTR";
int i ;
MyArrayList->Add(B1) ;
MyArrayList->Add(T1) ;
MyArrayList->Add(S) ;
MyArrayList->Add(i) ;
}
private: System::Void button1_Click_1(System::Object^ sender,
System::EventArgs^ e)
{
textBox1->Text =(MyArrayList[0]->Height)->ToString() ;
}
Compile error

33. Peak on Collections – ArrayList
private: System::Collections::ArrayList ^MyArrayList ;
private: System::Void Form1_Load(System::Object^ sender,
System::EventArgs^ e)
{
MyArrayList = gcnew System::Collections::ArrayList (4) ;
static int Counter = 0 ;
Button ^B1 = gcnew Button ;
TextBox ^T1 ;
String ^S = "ZGTR";
int i ;
MyArrayList->Add(B1) ;
MyArrayList->Add(T1) ;
MyArrayList->Add(S) ;
MyArrayList->Add(i) ;
}
private: System::Void button1_Click_1(System::Object^ sender,
System::EventArgs^ e)
{
textBox1->Text =(MyArrayList[0]->Height).ToString() ;
}
Compile error

34. ArrayList - dynamic_cast
private: System::Collections::ArrayList ^MyArrayList ;
private: System::Void Form1_Load(System::Object^ sender,
System::EventArgs^ e)
{
MyArrayList = gcnew System::Collections::ArrayList (4) ;
static int Counter = 0 ;
Button ^B1 = gcnew Button ;
TextBox ^T1 ;
String ^S = "ZGTR";
int i ;
MyArrayList->Add(B1) ;
MyArrayList->Add(T1) ;
MyArrayList->Add(S) ;
MyArrayList->Add(i) ;
}
private: System::Void button1_Click_1(System::Object^ sender,
System::EventArgs^ e)
{
textBox1->Text =((dynamic_cast <Button^>(MyArrayList[0]))->Height).ToString();
}
Everything is good. And will print 23. but why?

35. ArrayList - dynamic_cast
private: System::Collections::ArrayList ^MyArrayList ;
private: System::Void Form1_Load(System::Object^ sender,
System::EventArgs^ e)
{
MyArrayList = gcnew System::Collections::ArrayList (4) ;
static int Counter = 0 ;
Button ^B1 = gcnew Button ;
TextBox ^T1 ;
String ^S = "ZGTR";
int i ;
B1->Height = 30 ;
MyArrayList->Add(B1) ;
MyArrayList->Add(T1) ;
MyArrayList->Add(S) ;
MyArrayList->Add(i) ;
}
private: System::Void button1_Click_1(System::Object^ sender,
System::EventArgs^ e)
{
textBox1->Text =((dynamic_cast <Button^>(MyArrayList[0]))->Height).ToString();
}
Everything is good. And will print 30.

36. ArrayList
• It’s not a Generic*
– private: System::Collections::ArrayList ^MyArrayList ;
• Drop in performance!
_____________________________________________________
*Generic : class Typed

37. Enough said,
let’s dig deep live

38. That’s it for today!