Kalkulator-problem

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace WpfApplication1
{

/// Interaction logic for Window1.xaml

public partial class Window1 : Window
{
public Window1()
{
InitializeComponent();
}
int stdva = 0;
int x = 0;

private void button1_Click(object sender, RoutedEventArgs e)
{
if (textBox1.Text != "")
{
textBox1.Text = textBox1.Text + "0";
}
}

private void button2_Click(object sender, RoutedEventArgs e)
{
textBox1.Text = textBox1.Text + "1";
}

private void button3_Click(object sender, RoutedEventArgs e)
{
textBox1.Text = textBox1.Text + "2";
}

private void button4_Click(object sender, RoutedEventArgs e)
{
textBox1.Text = textBox1.Text + "3";
}

private void button5_Click(object sender, RoutedEventArgs e)
{
textBox1.Text = textBox1.Text + "4";
}

private void button6_Click(object sender, RoutedEventArgs e)
{
textBox1.Text = textBox1.Text + "5";
}

private void button7_Click(object sender, RoutedEventArgs e)
{
textBox1.Text = textBox1.Text + "6";
}

private void button8_Click(object sender, RoutedEventArgs e)
{
textBox1.Text = textBox1.Text + "7";
}

private void button9_Click(object sender, RoutedEventArgs e)
{
textBox1.Text = textBox1.Text + "8";
}

private void button10_Click(object sender, RoutedEventArgs e)
{
textBox1.Text = textBox1.Text + "9";
}

private void button11_Click(object sender, RoutedEventArgs e)
{
try
{
if (textBox1.Text != "")
{
if (stdva == 0)
{
stdva = Convert.ToInt32(textBox1.Text);
x = 0;
textBox1.Text = Convert.ToString(x);
}
else
{
if (stdva != Convert.ToInt32(textBox1.Text))
{
stdva = stdva + Convert.ToInt32(textBox1.Text);
x = 0;
textBox1.Text = Convert.ToString(x);
}
else
{
stdva = Convert.ToInt32(textBox1.Text);
x = 0;
textBox1.Text = Convert.ToString(x);
}
}
x = 1;
}
}
catch (System.FormatException)
{
}
}

private void button12_Click(object sender, RoutedEventArgs e)
{
try
{
if (textBox1.Text != "")
{
if (stdva == 0)
{
stdva = Convert.ToInt32(textBox1.Text);
x = 0;
textBox1.Text = Convert.ToString(x);
}
else
{
if (stdva != Convert.ToInt32(textBox1.Text))
{
stdva = stdva - Convert.ToInt32(textBox1.Text);
x = 0;
textBox1.Text = Convert.ToString(x);
}
else
{
stdva = Convert.ToInt32(textBox1.Text);
x = 0;
textBox1.Text = Convert.ToString(x);
}
}
x = 2;
}
}
catch (System.FormatException)
{
x = 0;
textBox1.Text = Convert.ToString(x);
}
}

private void button13_Click(object sender, RoutedEventArgs e)
{
try
{
if (textBox1.Text != "")
{
if (stdva == 0)
{
stdva = Convert.ToInt32(textBox1.Text);
x = 0;
textBox1.Text = Convert.ToString(x);
}
else
{
if (stdva != Convert.ToInt32(textBox1.Text))
{
stdva = stdva * Convert.ToInt32(textBox1.Text);
x = 0;
textBox1.Text = Convert.ToString(x);
}
else
{
stdva = Convert.ToInt32(textBox1.Text);
x = 0;
textBox1.Text = Convert.ToString(x);
}
}
x = 3;
}
}

catch (System.FormatException)
{
x = 0;
textBox1.Text = Convert.ToString(x);
}
}

private void button14_Click(object sender, RoutedEventArgs e)
{
try
{
if (textBox1.Text != "")
{
if (stdva == 0)
{
stdva = Convert.ToInt32(textBox1.Text);
x = 0;
textBox1.Text = Convert.ToString(x);
}
else
{
if (stdva != Convert.ToInt32(textBox1.Text))
{
if (textBox1.Text != "0")
{
stdva = stdva / Convert.ToInt32(textBox1.Text);
x = 0;
textBox1.Text = Convert.ToString(x);
}
else
{
textBox1.Text = "deljitelj je 0";
}
}
else
{
stdva = Convert.ToInt32(textBox1.Text);
x = 0;
textBox1.Text = Convert.ToString(x);
}

}
x = 4;
}
}

catch (System.FormatException)
{
x = 0;
textBox1.Text = Convert.ToString(x);
}
}

private void button15_Click(object sender, RoutedEventArgs e)
{
try
{
if (textBox1.Text != "")
{
switch (x)
{
case 1:
textBox1.Text = Convert.ToString(stdva + Convert.ToInt32(textBox1.Text));
stdva = Convert.ToInt32(textBox1.Text);
break;

case 2:
textBox1.Text = Convert.ToString(stdva - Convert.ToInt32(textBox1.Text));
stdva = Convert.ToInt32(textBox1.Text);
break;
case 3:
textBox1.Text = Convert.ToString(stdva * Convert.ToInt32(textBox1.Text));
stdva = Convert.ToInt32(textBox1.Text);
break;
case 4:
if (textBox1.Text != "0")
{
textBox1.Text = Convert.ToString(stdva / Convert.ToInt32(textBox1.Text));
stdva = Convert.ToInt32(textBox1.Text);
break;
}
else
{
textBox1.Text = "deljitelj je 0";
}
break;

}
}
else
{
x = 0;
textBox1.Text = Convert.ToString(x);
}

}

catch (System.FormatException)
{
x = 0;
textBox1.Text = Convert.ToString(x);
}
}

private void button16_Click(object sender, RoutedEventArgs e)//reset
{
x = 0;
textBox1.Text = Convert.ToString(x);
}

private void textBox1_TextChanged(object sender, TextChangedEventArgs e)
{

}
}
}

Naprimer, ko dam 6+5 mi seťteje da je to 11. Potem dam reset, vpiťem 2+3 in mi napiťe 16. to pomeni, da je 2+3=5 priťtel k prejťnjemu ra�unu (6+5), zato pa dobi 16. In to se vedno nadaljuje. ne vem zakaj ta reset ne dela tako kot bi moral.

pa obstaja kakšen lažji način kot tole ?

Ma jz moram to oddat profesorju do polnoči pa se že dva dni ubadam s tem. nam je pokazal edino le kako se vnaša gumbe pa textbox, zdj moramo pa kar kalkulator narest.