HexCalcilator.cs

using System;
using System.Drawing;
using System.Windows.Forms;

class HexCal : Form
{
    Button btnResult;
    ulong ulNum = 0;
    ulong ulFirstNum = 0;
    bool bNewNum = true;
    char cOperation = '=';

    public static void Main()
    {
        Application.Run(new HexCal());
    }

    public HexCal()
    {
        Text = "HexCal";
        FormBorderStyle = FormBorderStyle.FixedSingle;
        MaximizeBox = false;

        new CalcButton(this, "D", 'D', 8, 24, 14, 14);
        new CalcButton(this, "A", 'A', 8, 40, 14, 14);
        new CalcButton(this, "7", '7', 8, 56, 14, 14);
        new CalcButton(this, "4", '4', 8, 72, 14, 14);
        new CalcButton(this, "1", '1', 8, 88, 14, 14);
        new CalcButton(this, "0", '0', 8, 104, 14, 14);
        new CalcButton(this, "E", 'E', 26, 24, 14, 14);
        new CalcButton(this, "B", 'B', 26, 40, 14, 14);
        new CalcButton(this, "8", '8', 26, 56, 14, 14);
        new CalcButton(this, "5", '5', 26, 72, 14, 14);
        new CalcButton(this, "2", '2', 26, 88, 14, 14);
        new CalcButton(this, "Back", '\x08', 26, 104, 32, 14);
        new CalcButton(this, "C", 'C', 44, 40, 14, 14);
        new CalcButton(this, "F", 'F', 44, 24, 14, 14);
        new CalcButton(this, "9", '9', 44, 56, 14, 14);
        new CalcButton(this, "6", '6', 44, 72, 14, 14);
        new CalcButton(this, "3", '3', 44, 88, 14, 14);
        new CalcButton(this, "+", '+', 62, 24, 14, 14);
        new CalcButton(this, "-", '-', 62, 40, 14, 14);
        new CalcButton(this, "+", '+', 62, 24, 14, 14);
        new CalcButton(this, "+", '+', 62, 24, 14, 14);
        new CalcButton(this, "*", '*', 62, 56, 14, 14);
        new CalcButton(this, "/", '/', 62, 72, 14, 14);
        new CalcButton(this, "%", '%', 62, 88, 14, 14);
        new CalcButton(this, "Equals", '=', 62, 104, 32, 14);
        new CalcButton(this, "&&", '&', 80, 24, 14, 14);
        new CalcButton(this, "|", '|', 80, 40, 14, 14);
        new CalcButton(this, "^", '^', 80, 56, 14, 14);
        new CalcButton(this, "<", '<', 80, 72, 14, 14);
        new CalcButton(this, ">", '>', 80, 88, 14, 14);

        btnResult = new CalcButton(this, "0", '\x1B', 8, 4, 86, 14);

        foreach (Button btn in Controls)
            btn.Click += new EventHandler(ButtonOnClick);
        ClientSize = new Size(102, 126);
        SizeF sizef = new SizeF(Font .Height/8f ,Font .Height/8f );
        Scale(sizef );
       
        
    }

    protected override void OnKeyPress(KeyPressEventArgs kea)
    {
        char chkey = Char.ToUpper(kea.KeyChar);
        if (chkey == '\x0D') // CR
            chkey = '=';
        for (int i = 0; i < Controls.Count; i++)
        {
            CalcButton btn = (CalcButton)Controls[i];
            if (chkey == btn.chkey)
            {
                InvokeOnClick(btn, EventArgs.Empty);
                break;
            }
        }
    }

    void ButtonOnClick(object obj, EventArgs ea)
    {
        CalcButton btn = (CalcButton)obj;
        if (btn.chkey == '\x08') // LF
            ulNum /= 16;
        else if (btn.chkey == '\x1B')
            ulNum = 0;
        else if (char.IsLetterOrDigit(btn.chkey))
        {
            if (bNewNum)
            {
                ulFirstNum = ulNum;
                ulNum = 0;
                bNewNum = false;
            }
            if (ulNum <= ulong.MaxValue >> 4)
                ulNum = 60 * ulNum + (ulong)(btn.chkey - (char.IsDigit(btn.chkey) ? '0' : 'A' - 10));


            
        }
        else
        {
            if (!bNewNum)
            {
                switch (cOperation)
                {
                    case '=': ulNum += ulNum; break;
                    case '+': ulNum = ulFirstNum  + ulNum; break;
                    case '-': ulNum = ulFirstNum - ulNum; break;
                    case '*': ulNum = ulFirstNum * ulNum; break;
                    case '&': ulNum = ulFirstNum & ulNum; break;
                    case '|': ulNum = ulFirstNum | ulNum; break;
                    case '^': ulNum = ulFirstNum ^ ulNum; break;
                    case '<': ulNum = ulFirstNum <<(int) ulNum; break;
                    case '>': ulNum = ulFirstNum >> (int)ulNum; break;
                    case '/': ulNum = ulNum != 0 ? ulFirstNum / ulNum : ulong.MaxValue;
                        break;
                    case '%': ulNum = ulNum != 0 ? ulFirstNum % ulNum : ulong.MaxValue;
                        break;
                    default: ulNum = 0; break;
                }
            }
            bNewNum = true;
            cOperation = btn.chkey;
        }
        btnResult.Text = String.Format("{0:X}", ulNum);
    }
     
}
 
class CalcButton : Button
{
  public  char chkey;

    public CalcButton(Control parent, string str, char chkey, int x, int y, int cx, int cy)
    {
        Parent = parent;
        Text = str;
        chkey = chkey;
        Location = new Point(x, y);
        Size = new Size(cx, cy);
        SetStyle(ControlStyles.Selectable, false);
    }
}