C#

class PersonSorter : IComparer {
    public int Compare(object x1, object x2) {
        Person p1=x1 as Person;
        Person p2=x2 as Person;
        int diff=string.Compare(p1.LastName, p2.LastName);
        if (diff==0) diff=string.Compare(p1.FirstName, p2.FirstName);
        return diff;
    }
}

Person[] people=new Person[100];
// ... here some code to create 100 Persons
Array.Sort(people, new PersonSorter());
// ... now the people are sorted the way we wanted

public class Savings : Account {...}
public class Chequing : Account {...}
public class LineOfCredit : Account {...}
public class BigBusinessExpense : Account {...}

public Interface IFraudCheckable 
{
  bool CheckForFraud  ( date StartCheckingFrom, date EndCheckingAt );
}

public class Savings : Account, IFraudCheckable {...}
public class Chequing : Account, IFraudCheckable {...}
public class LineOfCredit : Account, IFraudCheckable {...}
public class BigBusinessExpense : Account, IFraudCheckable {...}

public class Account : IFraudCheckable
{
  ...
  public abstract bool CheckForFraud ( date StartCheckingFrom, date EndCheckingAt ) {};
  ...
}

AliNajjar wrote:

please I need URGENT help

AliNajjar wrote:

just like "etap" program does

[Serializable]
public class ImageInfo {
    public ImageInfo();
    public ImageInfo(string fullPath, int x, int y);
    public string Path { get; set; }
    public Point Location { get; set; }
}

private Stack<ImageInfo> m_Stack = new Stack<ImageInfo>();
...
m_Stack.Push(new ImageInfo(imagePath, 50, 50));
...
// Undo a particular action
ImageInfo old = m_Stack.Pop();

using (FileStream fs = new FileStream("yourFilePath", FileMode.Create, FileAccess.Write
      , FileShare.None, 0x1000, FileOptions.Encrypted | FileOptions.SequentialScan) {
    new BinaryFormatter().Serialize(fs, m_Stack.ToArray());
}

using (FileStream fs = new FileStream("yourFilePath", FileMode.Open, FileAccess.Read
      , FileShare.Read, 0x1000, FileOptions.Encrypted | FileOptions.SequentialScan) {
    m_Stack = new Stack<ImageInfo>((ImageInfo[])new BinaryFormatter().Deserialize(fs));
}