ASP.NET & Csharp (C#)

ASP.NET & Csharp (C#) , Here you can find my posts about .NET c# .

NumberStyles.None

Posted on by coder 
   
  
using System;
using System.Globalization;

public class StringParsing
{
   public static void Main()
   {
      string numericString;
      NumberStyles styles;


      numericString = "-30677";
      styles = NumberStyles.None;
      CallTryParse(numericString, styles);
    
   }

   private static void CallTryParse(string stringToConvert, NumberStyles styles)
   {
      Console.WriteLine(stringToConvert);
      short number;
      bool result = Int16.TryParse(stringToConvert, styles,CultureInfo.InvariantCulture, out number);
      if (result)
         Console.WriteLine(stringToConvert, number);
      else
         Console.WriteLine("failed.");
   }
}

NumberStyles.Integer

Posted on by coder 
   
  
using System;
using System.Globalization;

public class StringParsing
{
   public static void Main()
   {
      string numericString;
      NumberStyles styles;

      numericString = "10677";
      styles = NumberStyles.Integer;
      CallTryParse(numericString, styles);
    
   }

   private static void CallTryParse(string stringToConvert, NumberStyles styles)
   {
      Console.WriteLine(stringToConvert);
      short number;
      bool result = Int16.TryParse(stringToConvert, styles,CultureInfo.InvariantCulture, out number);
      if (result)
         Console.WriteLine(stringToConvert, number);
      else
         Console.WriteLine("failed.");
   }
}

InvalidCastException

Posted on by coder 
   
  

using System;
   
class MainClass
{
    public static void Main()
    {
        try
        {
            MainClass       MyObject = new MainClass();
            IFormattable    Formattable;
   
            Formattable = (IFormattable)MyObject;
        }
        catch(InvalidCastException)
        {
            Console.WriteLine("MyObject does not implement the IFormattable interface.");
   
        }
    }
}

Conversion Lookup

Posted on by coder 
   
  

/*
A Programmer's Introduction to C# (Second Edition)
by Eric Gunnerson

Publisher: Apress  L.P.
ISBN: 1-893115-62-3
*/

// 24 - User-Defined ConversionsHow It WorksConversion Lookup
// copyright 2000 Eric Gunnerson

public class ConversionLookup
{
    public static void Main()
    {
        S myS = new S();
        TBase tb = (TBase) myS;
    }
}
public class S
{
    public static implicit operator T(S s) 
    { 
        // conversion here
        return(new T());
    }
}

public class TBase
{
}

public class T: TBase
{
    
}

Classes and Pre and Post Conversions

Posted on by coder 
   
  

/*
A Programmer's Introduction to C# (Second Edition)
by Eric Gunnerson

Publisher: Apress  L.P.
ISBN: 1-893115-62-3
*/
// 24 - User-Defined ConversionsClasses and Pre and Post Conversions
// copyright 2000 Eric Gunnerson
using System;
using System.Text;

public class ClassesandPreandPostConversions
{
    public static void Main()
    {
        // implicit conversion section
        RomanNumeralAlternate    roman;
        roman = new RomanNumeralAlternate(55);
        
        BinaryNumeral binary = roman;
        // explicit conversion section
        BinaryNumeral binary2 = new BinaryNumeral(1500);
        RomanNumeralAlternate roman2;
        
        roman2 = (RomanNumeralAlternate) binary2;
    }
}

class RomanNumeral
{
    public RomanNumeral(short value) 
    {
        if (value > 5000)
        throw(new ArgumentOutOfRangeException());
        
        this.value = value;
    }
    public static explicit operator RomanNumeral(
    short value) 
    {
        RomanNumeral    retval;
        retval = new RomanNumeral(value);
        return(retval);
    }
    
    public static implicit operator short(
    RomanNumeral roman)
    {
        return(roman.value);
    }
    
    static string NumberString(
    ref int value, int magnitude, char letter)
    {
        StringBuilder    numberString = new StringBuilder();
        
        while (value >= magnitude)
        {
            value -= magnitude;
            numberString.Append(letter);
        }
        return(numberString.ToString());
    }
    
    public static implicit operator string(
    RomanNumeral roman)
    {
        int        temp = roman.value;
        
        StringBuilder retval = new StringBuilder();
        
        retval.Append(RomanNumeral.NumberString(ref temp, 1000, 'M'));
        retval.Append(RomanNumeral.NumberString(ref temp, 500, 'D'));
        retval.Append(RomanNumeral.NumberString(ref temp, 100, 'C'));
        retval.Append(RomanNumeral.NumberString(ref temp, 50, 'L'));
        retval.Append(RomanNumeral.NumberString(ref temp, 10, 'X'));
        retval.Append(RomanNumeral.NumberString(ref temp, 5, 'V'));
        retval.Append(RomanNumeral.NumberString(ref temp, 1, 'I'));
        
        return(retval.ToString());
    }
    public static implicit operator BinaryNumeral(RomanNumeral roman)
    {
        return(new BinaryNumeral((short) roman));
    }
    
    public static explicit operator RomanNumeral(
    BinaryNumeral binary)
    {
        return(new RomanNumeral((short)(int) binary));
    }
    
    private short value;
}
class BinaryNumeral
{
    public BinaryNumeral(int value) 
    {
        this.value = value;
    }
    public static implicit operator BinaryNumeral(
    int value) 
    {
        BinaryNumeral    retval = new BinaryNumeral(value);
        return(retval);
    }
    
    public static implicit operator int(
    BinaryNumeral binary)
    {
        return(binary.value);
    }
    
    public static implicit operator string(
    BinaryNumeral binary)
    {
        StringBuilder    retval = new StringBuilder();
        
        return(retval.ToString());
    }
    
    private int value;
}
class RomanNumeralAlternate : RomanNumeral
{
    public RomanNumeralAlternate(short value): base(value)
    {
    }
    
    public static implicit operator string(
    RomanNumeralAlternate roman)
    {
        return("NYI");
    }
}

User-Defined Conversions:A Simple Example

Posted on by coder 

   
  

/*
A Programmer's Introduction to C# (Second Edition)
by Eric Gunnerson

Publisher: Apress  L.P.
ISBN: 1-893115-62-3
*/
// 24 - User-Defined ConversionsA Simple Example
// copyright 2000 Eric Gunnerson
using System;
using System.Text;
struct RomanNumeral
{
    public RomanNumeral(short value) {
        if (value > 5000)
        throw(new ArgumentOutOfRangeException());
        
        this.value = value;
    }
    public static explicit operator RomanNumeral(short value) 
    {
        RomanNumeral    retval;
        retval = new RomanNumeral(value);
        return(retval);
    }
    
    public static implicit operator short(RomanNumeral roman)
    {
        return(roman.value);
    }
    
    static string NumberString(ref int value, int magnitude, char letter)
    {
        StringBuilder    numberString = new StringBuilder();
        
        while (value >= magnitude)
        {
            value -= magnitude;
            numberString.Append(letter);
        }
        return(numberString.ToString());
    }
    
    public static implicit operator string(
    RomanNumeral roman)
    {
        int        temp = roman.value;
        
        StringBuilder retval = new StringBuilder();
        
        retval.Append(RomanNumeral.NumberString(ref temp, 1000, 'M'));
        retval.Append(RomanNumeral.NumberString(ref temp, 500, 'D'));
        retval.Append(RomanNumeral.NumberString(ref temp, 100, 'C'));
        retval.Append(RomanNumeral.NumberString(ref temp, 50, 'L'));
        retval.Append(RomanNumeral.NumberString(ref temp, 10, 'X'));
        retval.Append(RomanNumeral.NumberString(ref temp, 5, 'V'));
        retval.Append(RomanNumeral.NumberString(ref temp, 1, 'I'));
        
        return(retval.ToString());
    }
    
    private short value;
}

public class UserDefinedConversionsASimpleExample
{
    public static void Main()
    {
        short s = 12;
        RomanNumeral numeral = new RomanNumeral(s);
        
        s = 165;
        numeral = (RomanNumeral) s;
        
        Console.WriteLine("Roman as int: {0}", (int)numeral);
        Console.WriteLine("Roman as string: {0}", (string)numeral);
        
        short s2 = numeral;
    }
}

Conversions of Classes (Reference Types):To the Base Class of an Object

Posted on by coder 

   
  

using System;

class Base
{
    public virtual void WhoAmI()
    {
        Console.WriteLine("Base");
    }
}
class Derived: Base
{
    public override void WhoAmI()
    {
        Console.WriteLine("Derived");
    }
}

public class TotheBaseClassofanObject {
    public static void Main()
    {
        Derived d = new Derived();
        Base b = d;
        
        b.WhoAmI();
        Derived d2 = (Derived) b;
        
        object o = d;
        Derived d3 = (Derived) o;
    }
}