WLC_Programming Knowledge

eg. Hex = 1AD, Dec =?
so, Hex   = (1 x 16(2)) +  (10 x 16(1)) + (13 x 16(0))
          = 256         +    160        +    13  
          = 429<10>
Hex(1AD)  = Dec(429)

using System;
using System.Windows.Forms;

namespace NumberTypeConverter
{
    public partial class HexadecimalConversion : Form
    {
        public HexadecimalConversion()
        {
            InitializeComponent();
        }

        public long HexToDecimal(string hex)
        {
            long Dec = 0;
            int power = 0;
            char[] HexDigits = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 
'A', 'B', 'C', 'D', 'E', 'F'};
            char[] HexArr = hex.ToCharArray();
            for (int i = HexArr.Length-1; i >=0; i--)
            {
                for (int j = 0; j < HexDigits.Length-1; j++)
                {
                    if (HexArr[i] == HexDigits[j])
                    {
                        Dec += (int)(j * Math.Pow(16, power));
                    }
                }
                power++;
            }
            return Dec;
        }

        private void btnConvert_Click(object sender, EventArgs e)
        {
            txtDecimal.Text = HexToDecimal(txtHexadecimal.Text.ToUpper()).ToString();
        }

        private void btnReset_Click(object sender, EventArgs e)
        {
            txtDecimal.Clear();
            txtHexadecimal.Clear();
            txtHexadecimal.Focus();
        }
    }
} 

Hex = 1AD, Dec=?
char[] HexDigits = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 
'A', 'B', 'C', 'D', 'E', 'F'};
char[] HexArr = { '1', 'A', 'D'};

Loop1 =>  for (int i = HexArr.Length-1; i >=0; i--) =>
          for (int i = 2; i >=0; i--) => true
           for (int j = 0; j < HexDigits.Length-1; j++) => 
           for (int j = 0; j < 15; j++) => true
      if (HexArr[i] == HexDigits[j]) => 
             if (HexArr[2] == HexDigits[13]) => true
  Dec = (int)(13 * Math.Pow(16, 0)); => 13

Loop2 =>  for (int i = 1; i >=0; i--) => true
    for (int j = 0; j < 15; j++) => true
      if (HexArr[1] == HexDigits[10]) => true
  Dec = (int)(10 * Math.Pow(16, 1)); => 160 

Loop3 =>  for (int i = 0; i >=0; i--) => true
    for (int j = 0; j < 15; j++) => true
      if (HexArr[0] == HexDigits[1]) => true
  Dec += (int)(1 * Math.Pow(16, 2)); => 256 
Loop4 =>  for (int i = -1; i >=0; i--) => false
so, Dec = Loop1 + Loop2 + Loop3 = 13 + 160 + 156 = 429