/*
?計算器
?能夠進行“+”“-”“*”“/”四項雙目運算
?能進行“√”求算數平方根運算和“||”求絕對值運算
?運算按照輸入順序進行，不支持括號嵌套
?????*/
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?Calculator
{
????public?partial?class?Calculator?:?Form
????{
????????private?bool?isFirstInput?=?true;???//是否第一次輸入??
????????private?string?lastVal?=?““;?????????//雙目運算的前一個數??
????????private?string?symbol?=?““;?????????//保存
????????private?bool?isCanCalc?=?false;?????//判斷
????????private?bool?isClr?=?false;
????????public?Calculator（）
????????{
????????????InitializeComponent（）;
????????}

????????private?void?Form1_Load（object?sender?EventArgs?e）
????????{
????????????Rtext.Enabled?=?false;??????//禁止人為手動修改??
????????????Ctext.Enabled?=?false;??
????????????Rtext.Text?=?““;????????????//初始化
????????????Ctext.Text?=?““;?
????????}

????????private?void?NumBtn_Click（object?sender?EventArgs?e）
????????{
????????????string?numStr?=?（sender?as?Button）.Text;?
????????????if?（isClr?==?true）
????????????{??????????????????????
????????????????Ctext.Text?=?““;???
????????????????isClr?=?false;
????????????}

????????????if?（Ctext.Text?==?““）
????????????????Ctext.Text?=?numStr;
????????????else
????????????????Ctext.Text?+=?numStr;

????????????if?（isFirstInput?==?false）??
????????????????isCanCalc?=?true;
????????}

????????private?void?Spot_Btn_Click（object?sender?EventArgs?e）
????????{
????????????string?str?=?（sender?as?Button）.Text;

????????????if?（Ctext.Text.IndexOf（str）?==?-1）?
????????????{??????????????????????????????????
????????????????Ctext.Text?+=?str;
????????????}
????????}

????????private?void?Sqrt_Btn_Click（object?sender?EventArgs?e）
????????{
????????????string?str?=?Ctext.Text;??
????????????double?val?=?double.Parse（str）;?????
????????????if?（val?????????????????MessageBox.Show（“負數不可開平方根!“?“error“）;
????????????val?=?Math.Sqrt（val）;????????????????
????????????Ctext.Text?=?val.ToString（）;
????????}

????????private?void?CE_Btn_Click（object?sender?EventArgs?e）
????????{
????????????Ctext.Text?=?““;
????????}
????????private?void?button6_Click（object?sender?EventArgs?e）
????????{
????????????string?str?=?Ctext.Text;???
????????????double?val?=?double.Parse（str）;
????????????if?（val?????????????????val?=?-val;
????????????Ctext.Text?=?val.ToString（）;
????????}
????????private?double?Calc（double?v1?double?v2?string?symbol）
????????{
????????????double?result?=?0.0;
????????????switch?（symbol）
????????????{
????????????????case?“+“:
????????????????????result?=?v1?+?v2;?break;
????????????????case?“-“:
????????????????????result?=?v1?-?v2;?break;
????????????????case?“*“:
????????????????????result?=?v1?*?v2;?break;
????????????????case?“/“:
????????????????????if?（v2?==?0）
?????????

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????目錄???????????0??2017-11-26?15:27??Calculator（可視化計算器）\
?????目錄???????????0??2017-11-26?15:27??Calculator（可視化計算器）\.vs\
?????目錄???????????0??2017-11-26?15:27??Calculator（可視化計算器）\.vs\Calculator\
?????目錄???????????0??2017-11-26?15:27??Calculator（可視化計算器）\.vs\Calculator\v15\
?????文件???????57344??2018-06-30?22:48??Calculator（可視化計算器）\.vs\Calculator\v15\.suo
?????目錄???????????0??2017-12-26?20:58??Calculator（可視化計算器）\Calculator\
?????文件?????????998??2017-07-11?19:23??Calculator（可視化計算器）\Calculator.sln
?????文件?????????189??2017-07-11?19:23??Calculator（可視化計算器）\Calculator\App.config
?????目錄???????????0??2017-11-26?15:27??Calculator（可視化計算器）\Calculator\bin\
?????目錄???????????0??2017-11-26?15:27??Calculator（可視化計算器）\Calculator\bin\Debug\
?????文件???????16384??2017-12-26?20:58??Calculator（可視化計算器）\Calculator\bin\Debug\Calculator.exe
?????文件?????????189??2017-07-11?19:23??Calculator（可視化計算器）\Calculator\bin\Debug\Calculator.exe.config
?????文件???????28160??2017-12-26?20:58??Calculator（可視化計算器）\Calculator\bin\Debug\Calculator.pdb
?????目錄???????????0??2017-07-11?21:33??Calculator（可視化計算器）\Calculator\bin\Release\
?????文件????????5328??2017-12-26?20:58??Calculator（可視化計算器）\Calculator\Calculator.cs
?????文件????????3592??2017-07-11?21:33??Calculator（可視化計算器）\Calculator\Calculator.csproj
?????文件???????23539??2017-07-11?23:01??Calculator（可視化計算器）\Calculator\Calculator.Designer.cs
?????文件????????5817??2017-12-26?20:58??Calculator（可視化計算器）\Calculator\Calculator.resx
?????目錄???????????0??2017-11-26?15:27??Calculator（可視化計算器）\Calculator\obj\
?????目錄???????????0??2017-12-26?20:58??Calculator（可視化計算器）\Calculator\obj\Debug\
?????文件?????????180??2017-12-26?20:58??Calculator（可視化計算器）\Calculator\obj\Debug\Calculator.Calculator.resources
?????文件????????2407??2017-12-26?20:54??Calculator（可視化計算器）\Calculator\obj\Debug\Calculator.csproj.FileListAbsolute.txt
?????文件????????1075??2017-12-26?20:58??Calculator（可視化計算器）\Calculator\obj\Debug\Calculator.csproj.GenerateResource.Cache
?????文件????????2384??2017-07-11?20:14??Calculator（可視化計算器）\Calculator\obj\Debug\Calculator.csprojResolveAssemblyReference.cache
?????文件???????16384??2017-12-26?20:58??Calculator（可視化計算器）\Calculator\obj\Debug\Calculator.exe
?????文件???????28160??2017-12-26?20:58??Calculator（可視化計算器）\Calculator\obj\Debug\Calculator.pdb
?????文件?????????180??2017-12-26?20:53??Calculator（可視化計算器）\Calculator\obj\Debug\Calculator.Properties.Resources.resources
?????文件??????????42??2017-12-26?20:27??Calculator（可視化計算器）\Calculator\obj\Debug\CoreCompileInputs.cache
?????文件????????1464??2017-07-11?22:59??Calculator（可視化計算器）\Calculator\obj\Debug\DesignTimeResolveAssemblyReferences.cache
?????文件????????7466??2017-12-26?20:27??Calculator（可視化計算器）\Calculator\obj\Debug\DesignTimeResolveAssemblyReferencesInput.cache
?????文件???????????0??2017-07-11?19:23??Calculator（可視化計算器）\Calculator\obj\Debug\TemporaryGeneratedFile_036C0B5B-1481-4323-8D20-8F5ADCB23D92.cs
............此處省略12個文件信息