Calculator/MainWindow.xaml.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
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 Calculator
{
    /// <summary>
    /// Логика взаимодействия для MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
            Fun.ItemsSource = new List<string>()
            {
                "+", "-", "*", "/", "x^y", "√", "%", "Log", "sin", "Ctg"
            };
        }

        private void Result(object sender, RoutedEventArgs e)
        {
            int a = Convert.ToInt32(x1.Text);
            int b = Convert.ToInt32(x2.Text);
            int sel = Fun.SelectedIndex;
            switch(sel)
            {
                case 0:
                    Res.Text = Plus(a,b).ToString();
                    break;
                case 1:
                    Res.Text = Minus(a, b).ToString();
                    break;
                case 2:
                    Res.Text = Divide(a, b).ToString();
                    break;
                case 3:
                    Res.Text = Multiply(a, b).ToString();
                    break;
                case 4:
                    Res.Text = Power(a, b).ToString();
                    break;
                case 5:
                    Res.Text = Root(a).ToString();
                    break;
                case 6:
                    Res.Text = Percent(a, b).ToString();
                    break;
                case 7:
                    Res.Text = Log(a, b).ToString();
                    break;
                case 8:
                    Res.Text = Sin(a).ToString();
                    break;
                case 9:
                    Res.Text = Ctg(a, b).ToString();
                    break;
                default:
                    MessageBox.Show("Выберите функцию");
                    break;
            }
        }

        #region Функции
        static public double Plus(double a, double b)
        {
            return a + b;
        }
        static public double Minus(double a, double b)
        {
            return a - b;
        }
        static public double Divide(double a, double b)
        {
            return a / b;
        }
        static public double Multiply(double a, double b)
        {
            return a * b;
        }
        static public double Power(double a, double b)
        {
            return Math.Pow(a, b);
        }
        static public double Root(double a)
        {
            return Math.Sqrt(a);
        }
        static public double Percent(double a, double b)
        {
            return a / 100 * b;
        }
        static public double Log(double a, double b)
        {
            return Math.Log(a, b);
        }
        static public double Sin(double a)
        {
            return Math.Sin(a);
        }
        static public double Ctg(double a, double b)
        {
            return Math.Cos(a) / Math.Sin(b);
        }
        #endregion

        private void Fun_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            if (Fun.SelectedItem.ToString()=="sin" || Fun.SelectedItem.ToString() == "√")
            {
                x2.Visibility = Visibility.Collapsed;
            }
            else
            {
                x2.Visibility= Visibility.Visible;
            }
        }
    }
}