Programming

C# implicit operator

SAJJAD — Fri, 20 Aug 2010 10:46:54 +0000

public class StringSafe
{
	/// < summary>
	/// Empty value
	/// < /summary>
	public const string Empty = "";

	/// < summary>
	/// String to StringSafe
	/// < /summary>
	/// < param name="data">object< /param>
	/// < returns>< /returns>
	public static implicit operator StringSafe(String data)
	{
		if (data == null)
			return Empty;

		return new StringSafe(data);
	}

	/// < summary>
	/// StringSafe to String
	/// < /summary>
	/// < param name="data">object< /param>
	/// < returns>< /returns>
	public static implicit operator String(StringSafe data)
	{
		if (data == null)
			return Empty;

		return data.value;
	}

	private String value = Empty;
	/// < summary>
	/// Value
	/// < /summary>
	public String Value
	{
		get
		{
			if (this.value == null)
			return Empty;

			return this.value;
		}
		set
		{
			if (value == null)
			this.value = Empty;
			else
			this.value = value;
		}
	}

	/// < summary>
	/// Create new instance of StringSafe
	/// < /summary>
	/// < param name="value">< /param>
	public StringSafe(String value = Empty)
	{
		this.value = value;
	}
}

Sample

public class Program
{
	StringSafe sf = "SAJJAD";
	MessageBox.Show(sf);
}

Anonymous Struct

SAJJAD — Wed, 18 Aug 2010 13:24:38 +0000

var Freinds = new[]
{
	new { Name = "Ali", Age = 23 , Married = false },
	new { Name = "Reza", Age = 43  , Married = true },
	new { Name = "Ehsan", Age = 36 , Married = true },
	new { Name = "Mahdi", Age = 34 , Married = false }
};

String Output = String.Empty;

foreach (var v in Freinds.Where(a => a.Married))
	Output += "Name: " + v.Name + ", Age:" + v.Age + ";";

if (Output.Length > 0)
	MessageBox.Show(Output.Substring(0, Output.Length - 1));

C# Sarray (Advaned Generic/Object Array)

SAJJAD — Mon, 12 Apr 2010 17:03:39 +0000

Sarray: Queueable, Stackable, Enumerable, Collectable, Listable, Disposable, Timmeable Array !
Add, Insert, Remove, Enqueue, Dequeue, Pop, Push @ Range

Enjoy, SAJJAD

    [System.Diagnostics.DebuggerDisplay("Count = { Count }")]
    public class Sarray< T > : ISarray, ISarray< T >
    {
        protected T[] Items;

        public Sarray(bool queueTimered, double timmerTick, int queuesCapacity)
        {
            this.Clear();

            if (queueTimered)
            {
                this.queueTimer = new Timer(timmerTick);
                this.queueTimer.Elapsed += new ElapsedEventHandler(queueTimer_Elapsed);
            }

            this.queuesCapacity = queuesCapacity;

            this.Enqueues();
            this.Dequeues();

            if (queueTimered)
            {
                this.queueTimer.Start();
            }
        }

        #region { List }

        int IList.Add(object value)
        {
            return this.InsertCore(this.Items.Length, (T)value);
        }

        void IList.Clear()
        {
            this.Clear();
        }

        bool IList.Contains(object value)
        {
            return this.Contains((T)value);
        }

        int IList.IndexOf(object value)
        {
            return this.IndexOf((T)value);
        }

        void IList.Insert(int index, object value)
        {
            this.InsertCore(index, (T)value);
        }

        bool IList.IsFixedSize
        {
            get { return false; }
        }

        bool IList.IsReadOnly
        {
            get { return false; }
        }

        void IList.Remove(object value)
        {
            this.DeleteCore((T)value);
        }

        void IList.RemoveAt(int index)
        {
            this.DeleteCore(index, index + 1);
        }

        object IList.this[int index]
        {
            get
            {
                return this[index];
            }
            set
            {
                this[index] = (T)value;
            }
        }

        void ICollection.CopyTo(Array array, int index)
        {
            if (this.IsIndex(index, false))
            {
                Items.CopyTo(array, index);
            }
        }

        int ICollection.Count
        {
            get { return this.Items.Length; }
        }

        bool ICollection.IsSynchronized
        {
            get { return true; }
        }

        object ICollection.SyncRoot
        {
            get { return this; }
        }

        #endregion

        #region { IList< T > }

        public virtual int IndexOf(T item)
        {
            for (int i = 0; i < this.Items.Length; i++)
            {
                if (this.Items[i].Equals(item))
                    return i;
            }

            return -1;
        }

        public virtual void Insert(int index, T item)
        {
            this.InsertCore(index, item);
        }

        public virtual void RemoveAt(int index)
        {
            this.DeleteCore(index, index + 1);
        }

        public virtual T this[int index]
        {
            get
            {
                return this.Seek(index);
            }
            set
            {
                T co = this.Seek(index);
                if (co != null)
                {
                    co = value;
                }
            }
        }

        public virtual void Add(T item)
        {
            this.InsertCore(this.Items.Length, item);
        }

        public virtual void Clear()
        {
            this.Items = new T[] { };
        }

        public virtual bool Contains(T item)
        {
            foreach (T co in this.Items)
            {
                if (co.Equals(item))
                    return true;
            }
            return false;
        }

        public virtual void CopyTo(T[] array, int arrayIndex)
        {
            if (this.IsIndex(arrayIndex, false))
            {
                Array.Copy(this.Items, array, arrayIndex);
            }
        }

        public virtual int Count
        {
            get { return this.Items.Length; }
        }

        public virtual bool IsReadOnly
        {
            get { return false; }
        }

        public virtual bool Remove(T item)
        {
            return this.RemoveRange(item) > 0;
        }

        public virtual IEnumerator< T > GetEnumerator()
        {
            foreach (T co in this.Items)
                yield return co;
        }

        IEnumerator IEnumerable.GetEnumerator()
        {
            return this.Items.GetEnumerator();
        }

        #endregion

        #region { IDisposible }

        private bool disposed = false;
        public bool Disposed
        {
            get
            {
                return this.disposed;
            }
        }

        public virtual void Dispose()
        {
            if (!this.disposed)
            {
                this.Items = null;
                this.enqueue = null;
                this.dequeue = null;

                this.queueTimer.Dispose();
                this.queueTimer = null;
            }
        }

        #endregion

        public virtual bool IsIndex(int index, bool withEnd)
        {
            if (withEnd)
                return index >= 0 && index <= this.Items.Length;

            return index >= 0 && index < this.Items.Length;
        }

        public virtual T Seek(int index)
        {
            for (int i = 0; i < this.Items.Length; i++)
            {
                if (i == index)
                    return this.Items[i];
            }

            return default(T);
        }
        public virtual IEnumerable Seek(int from, int to)
        {
            if (this.IsIndex(from, false) && this.IsIndex(to, true) && from < to && from != to)
            {
                for (int i = 0; i < this.Items.Length; i++)
                {
                    if (i >= from && i < to)
                    {
                        yield return this.Items[i];
                    }
                }
            }
        }

        public virtual int Push(T iteme)
        {
            return this.InsertCore(this.Items.Length, iteme);
        }
        public virtual int PushRange(params T[] itemes)
        {
            return this.InsertCore(this.Items.Length, itemes);
        }
        public virtual int AddRange(params T[] items)
        {
            return this.InsertCore(this.Items.Length, items);
        }
        public virtual int InsertRange(int index, params T[] items)
        {
            return this.InsertCore(index, items);
        }

        public virtual int Pop(int count = 1)
        {
            if (count > 0)
                return this.DeleteCore(this.Items.Length - count, this.Items.Length);

            return 0;
        }
        public virtual int RemoveRange(params T[] items)
        {
            return this.DeleteCore(items);
        }

        protected virtual int InsertCore(int index, params T[] items)
        {
            Int32 newRealMembers = 0;

            if (items != null && this.IsIndex(index, true))
            {
                if (items.Length > 0) // At least one new child want added
                {
                    // We thing all new childs are new
                    T[] newMembers = new T[items.Length];

                    // Flag for child existance
                    Boolean exist = false;

                    // Check existance
                    foreach (T item in items)
                    {
                        if (item != null)
                        {
                            exist = false;
                            foreach (T at in this.Items)
                                if (at.Equals(item))
                                    exist = true;

                            if (!exist)
                                newMembers[newRealMembers++] = item;
                        }
                    }

                    if (newRealMembers > 0)
                    {
                        T[] newArray = new T[this.Items.Length + newRealMembers];

                        for (int i = 0, j = 0; i < newArray.Length; )
                        {
                            if (index == i)
                            {
                                for (int z = 0; z < newRealMembers; z++)
                                {
                                    newArray[i++] = newMembers[z];
                                }
                            }
                            else
                            {
                                newArray[i++] = this.Items[j++];
                            }
                        }
                        this.Items = newArray;
                    }
                }
            }

            return newRealMembers;
        }
        protected virtual int DeleteCore(params T[] items)
        {
            Int32 newMembers = 0, lastSize = 0;

            if (items != null)
            {
                if (items.Length > 0)
                {
                    T[] newArray = new T[this.Items.Length];

                    // Is item exist ?
                    Boolean exist = false;

                    // Find no selected childs
                    foreach (T t in this.Items)
                    {
                        exist = false;

                        foreach (T item in items)
                        {
                            if (t.Equals(item))
                            {
                                exist = true;
                                break;
                            }
                        }

                        if (!exist)
                        {
                            newArray[newMembers++] = t;
                        }
                    }

                    if (newMembers > 0 && newMembers != this.Items.Length)
                    {
                        lastSize = this.Items.Length;
                        Array.Resize(ref newArray, newMembers);
                        this.Items = newArray;
                    }
                }
            }

            return lastSize - newMembers;
        }
        protected virtual int DeleteCore(int from, int to)
        {
            int applied = 0;

            if (this.IsIndex(from, false) && this.IsIndex(to, true) && from < to && from != to)
            {
                T[] newArray = new T[this.Items.Length - (from - to)];

                for (int i = 0, newIndex = 0; i < this.Items.Length; i++)
                {
                    if (i >= from && i < to)
                    {
                        newArray[newIndex++] = this.Items[i];
                    }
                }
                applied = from - to;
                this.Items = newArray;

            }

            return applied;
        }

        #region { Timer }

        private bool queueTimered = false;
        public bool QueueTimered
        {
            get
            {
                return this.queueTimered;
            }
        }

        private Timer queueTimer;
        private void queueTimer_Elapsed(object sender, ElapsedEventArgs e)
        {
            this.Enqueues();
            this.Dequeues();
        }

        ///

        /// Queue Refresh Time (100 to 10000 ms, 1000 is default)
        ///

C# Define Field, Property, Method or Class

SAJJAD — Fri, 30 Oct 2009 12:12:44 +0000

[|new] [public|internal|protected|private] [static] [|virtual|abstract|sealed] [|override] Type NAME;

C# partial Keyword

SAJJAD — Sun, 25 Oct 2009 18:07:24 +0000

using System;

namespace ConsoleApplication
{
	static class Program
	{
		static void Main()
		{
			User a = new User();
			Console.WriteLine(User.Instance);

			User b = new User();
			Console.WriteLine(User.Instance);

			Console.Read();
		}
	}

	public enum Gender
	{
		Male,
		Female
	}

	public partial class User
	{
		private Gender _gender;

		public Gender Gender
		{
			get
			{
				return this._gender;
			}

			set
			{
				this._gender = value;
			}
		}

		public User()
		{
			Instance++;
		}

		~User()
		{
			Instance--;
		}
	}

	public partial class User
	{
		public static int Instance = 0;
		public static readonly User Empty;
	}
}

C# virtual Keywords: More speed

SAJJAD — Wed, 14 Oct 2009 19:01:34 +0000

using System;

namespace ConsoleApplication
{
	class Program
	{
		static void Main(string[] args)
		{
			Console.WriteLine("Area of 5 is: " + (new Circle(5).Area()).ToString());
			Console.WriteLine("Perimeter of 5 is: " + (new Circle(5).Perimeter()).ToString());

			Circle C = new Circle(8.5);
			Console.WriteLine("\nArea of 8.5 is: " + C.Area().ToString());
			Console.WriteLine("Perimeter of 8.5 is: " + C.Perimeter().ToString());

			Console.Read();
		}
	}

	abstract class Shape
	{
		public double X, Y;

		public Shape() : this(0) { }
		public Shape(double X)
		{
			this.X = this.Y = X;
		}
		public Shape(double X, double Y)
		{
			this.X = X;
			this.Y = Y;
		}

		public virtual double Area()
		{
			return this.X * this.Y;
		}

		public virtual double Perimeter()
		{
			return 2 * this.X * this.Y;
		}
	}

	sealed class Circle : Shape
	{
		public Circle() : base(0) { }
		public Circle(double Radius) : base(Radius) { }

		public override double Area()
		{
			return Math.PI * this.X * this.X;
		}

		public override double Perimeter()
		{
			return 2 * Math.PI * this.X;
		}
	}
}

C# params Keywords

SAJJAD — Wed, 14 Oct 2009 18:00:49 +0000

using System;

namespace ConsoleApplication
{
	class Program
	{
		static void Main(string[] args)
		{
			if (Containt(typeof(int), new object[] { true, 1, 110.1F, 20L, 80.0001D, "SAJJAD", DateTime.Now }))
			{
				Console.WriteLine("Array contain Int32 type !");
			}

			if (Containt(typeof(DateTime), true, 1, 110.1F, 20L, 80.0001D, "SAJJAD", DateTime.Now))
			{
				Console.WriteLine("Array contain Datetime type !");
			}

			Console.ReadLine();
		}

		static bool Containt(Type type, params object[] list)
		{
			foreach (object obj in list)
				if (obj.GetType() == type)
					return true;

			return false;
		}
	}
}

Abstract, Sealed & Static modifiers in C#

SAJJAD — Fri, 09 Oct 2009 21:38:11 +0000

C# provides many modifiers for use with types and type members. Of these, three can be used with classes: abstract, sealed and static.

abstract
The abstract modifier indicates that the thing being modified has a missing or incomplete implementation. The abstract modifier can be used with classes, methods, properties, indexers, and events. Use the abstract modifier in a class declaration to indicate that a class is intended only to be a base class of other classes. Members marked as abstract, or included in an abstract class, must be implemented by classes that derive from the abstract class

abstract class A {}
A a = new A(); //Error

sealed
When applied to a class, the sealed modifier prevents other classes from inheriting from it. In the following example, class B inherits from class A, but no class can inherit from class B.

sealed class A {}
class B:A {} //Error

static
The static modifier can be used with classes, fields, methods, properties, operators, events, and constructors, but it cannot be used with indexers, destructors, or types other than classes. The static modifier on a class means that the class cannot be instantiated, and that all of its members are static. A static member has one version regardless of how many instances of its enclosing type are created

static class A {}
A a = new A(); //Error
/* All member must be static */

C# Reserved and Contextual Keywords

SAJJAD — Thu, 08 Oct 2009 01:47:44 +0000

Magic keywords
__arglist | __makeref | __reftype | __refvalue

Keywords as an identifier
@typeof @goto = @for.@switch(@throw);

C# 1.0 Contextual keywords
get | set | value | add | remove

C# 2.0 Contextual keywords
where | partial | global | yield | alias

C# 4.0 Contextual keywords
dynamic

C# speed: ‘return’ vs ‘yield return’

SAJJAD — Wed, 07 Oct 2009 17:43:44 +0000

Declare;

public static T[] Reserve< T>(T[] array)
{
	T[] newArray = new T[array.Length];

	for (i = 0; i < array.Length; i++)
		newArray[i] = array[array.Length - 1 - i];

	return newArray;
}

public static IEnumerable ReserveAsync< T>(T[] array)
{
	for (i = 0; i < array.Length; i++)
		yield return array[array.Length - 1 - i];
}

Use;

int[] ii = new int[] { 1, 2, 3, 4, 5, 6, 7, 8, 9 };

long a;

a = DateTime.Now.Ticks;
foreach (int i in xArray.Reserve(ii))
	Debug.WriteLine(i);
Debug.WriteLine(DateTime.Now.Ticks - a);

a = DateTime.Now.Ticks;
foreach (int i in xArray.ReserveAsync(ii))
	 Debug.WriteLine(i);
Debug.WriteLine(DateTime.Now.Ticks - a);

Result;
ReserveAsync often is 60% faster than Reserve