C#

m_mazhar wrote:

Is there any class which capture events that any file is opened in a system. Plz reply

<br />
		[Flags]<br />
		enum testenum { In, Out, Over, Hover }<br />
<br />
		static void PrintFlags(string[] names, IList curnames, int idx) {<br />
<br />
			if (idx == names.Length) { // print all names contained in list<br />
				if (curnames.Count == 0) {<br />
					System.Console.WriteLine("[None]");<br />
				} else {<br />
					for (int i = 0; i < curnames.Count - 1; i++)<br />
						System.Console.Write("{0}, ", curnames[i]);<br />
					System.Console.WriteLine(curnames[curnames.Count - 1]);<br />
				}<br />
				return;<br />
			}<br />
<br />
			// test with name<br />
			curnames.Add(names[idx]);<br />
			PrintFlags(names, curnames, idx + 1);<br />
<br />
			// test without name<br />
			curnames.RemoveAt(curnames.Count - 1);<br />
			PrintFlags(names, curnames, idx + 1);<br />
		}<br />
<br />
		static void Main(string[] args) {<br />
<br />
			string[] names = Enum.GetNames(typeof(testenum));<br />
			ArrayList curnames = new ArrayList(names.Length);<br />
			PrintFlags(names, curnames, 0);<br />
			<br />
		}<br />

using System;
using System.Collections;

public class MyClass
{
    // enum MUST must have fewer entries than the width of an int - 1,
    // i.e. a maximum of 31 or 63 depending on CPU, but to be honest any more
    // than 16 is just silly!

    [Flags]
    enum testEnum
    {
        In,
        Out,
        Over,
        Hover
    }

    static void Main (string[] args) 
    {
        string[] names = Enum.GetNames (typeof (testEnum));
        ArrayList[] list = GetCombinations (names);

        foreach (ArrayList items in list)
            for (int i = 0, last = items.Count - 1; i <= last; i++)
                Console.Write (items [i] + (i < last ? ", " : "\n"));

        Console.ReadLine();
    }

    static ArrayList[] GetCombinations (string[] a)
    {
        int count = TwoPow (a.Length) - 1;
        ArrayList[] list = new ArrayList [count];

        for (uint i = 1; i <= count; i++)
        {
            ArrayList items = new ArrayList();

            for (uint j = 0, bits = i; bits != 0; j++, bits >>= 1)
                if ((bits & 1) != 0)
                    items.Add (a [j]);

            list [i - 1] = items;
        }
        
        return list;
    }

    static int TwoPow (int e)
    {
        int p = 1;
        for (int i = 0; i < e; i++)
            p <<= 1;

        return p;
    }
}