004 C# 윈도우 프로그래밍

목표: 003 프로젝트에 예외를 처리 한다.

 

소스코드 : 

using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Windows.Forms; namespace WindowsFormsApplication1 {     public enum Arithmetic     {         plus,         minus,         multiple,         divison     }     public partial class Form1 : Form     {         public Form1()         {             InitializeComponent();             this.Clear();         }         private double GetNum(string str)         {             double returnValue = 0;             if(string.IsNullOrEmpty(str))             {                 MessageBox.Show("공백 입니다, 숫자를 입력하세요");                 this.Clear();                 throw new Exception("공백 입니다, 숫자를 입력하세요");             }             try             {                 returnValue = double.Parse(str);             }             catch             {                 MessageBox.Show("숫자를 입력하세요");                 this.Clear();                 throw new Exception("숫자를 입력하세요");             }             return returnValue;         }         private double GetNum1()         {             return GetNum(this.textNum1.Text);         }         private double GetNum2()         {             return GetNum(this.textNum2.Text);         }         private void btnAdd_Click(object sender, EventArgs e)         {             double num1 = GetNum1();             double num2 = GetNum2();             double num = Operate(num1, num2, Arithmetic.plus);             this.textResult.Text = num.ToString();             this.lbResult.Text = "+";         }         private void btnClear_Click(object sender, EventArgs e)         {             this.Clear();         }         private void Clear()         {             this.textNum1.Text = "";             this.textNum2.Text = "";             this.textResult.Text = "";             this.lbResult.Text = "Ready";         }         private double Operate(double num1, double num2, Arithmetic ari)         {             double returnValue = 0.0;             switch(ari)             {                 case Arithmetic.plus:                     returnValue = num1 + num2;                     break;                 case Arithmetic.minus:                     returnValue = num1 - num2;                     break;                 case Arithmetic.multiple:                     returnValue = num1 * num2;                     break;                 case Arithmetic.divison:                                         returnValue = num1 / num2;                     break;             }             return returnValue;         }     } }