3. Calculator (call function)

usingSystem;usingSystem.Collections.Generic;usingSystem.ComponentModel;usingSystem.Data;usingSystem.Drawing;usingSystem.Linq;usingSystem.Text;usingSystem.Windows.Forms;namespacestudentform{ Public Partial classJisuanqi:form {Private decimalJieguo; Private stringYunsuanfu;  PublicJisuanqi () {InitializeComponent (); }        Private voidJiashuzi (stringShuzi) {            if(Txtshuru. Text = ="0") {Txtshuru. Text=Shuzi; }            Else{Txtshuru. Text+=Shuzi; }        }        Private voidJiayunsuanfu (stringYunsuanfu) {            if(Txtjisuanshi. Text.trim (). Length = =0&& Txtshuru. Text = ="0") {Label1. Text="Please enter a number first. "; }            Else            {                if(Yunsuanfu = ="+") {Jieguo+=decimal. Parse (Txtshuru.                Text.trim ()); }                Else if(Yunsuanfu = ="-") {Jieguo-=decimal. Parse (Txtshuru.                Text.trim ()); }                Else if(Yunsuanfu = ="*") {Jieguo*=decimal. Parse (Txtshuru.                Text.trim ()); }                Else if(Yunsuanfu = ="/") {Jieguo/=decimal. Parse (Txtshuru.                Text.trim ()); }                Else if(Yunsuanfu = ="%") {Jieguo%=decimal. Parse (Txtshuru.                Text.trim ()); }                Else{Jieguo=decimal. Parse (Txtshuru.                Text.trim ()); } Txtjisuanshi. Text+=Txtshuru.                Text; Txtjisuanshi. Text+=Yunsuanfu; Yunsuanfu=Yunsuanfu; Txtshuru. Text="0"; }        }        Private voidBtndeng_click (Objectsender, EventArgs e) {Jiayunsuanfu (Btndeng).            Text); Txtshuru. Text=jieguo.tostring (); }        #region= = Digital button click event = =Private voidBtnling_click (Objectsender, EventArgs e) {Jiashuzi (btnling).        Text); }        Private voidBtnyi_click (Objectsender, EventArgs e) {Jiashuzi (Btnyi).        Text); }        Private voidBtner_click (Objectsender, EventArgs e) {Jiashuzi (Btner).        Text); }        Private voidBtnsan_click (Objectsender, EventArgs e) {Jiashuzi (Btnsan).        Text); }        Private voidBtnsi_click (Objectsender, EventArgs e) {Jiashuzi (Btnsi).        Text); }        Private voidBtnwu_click (Objectsender, EventArgs e) {Jiashuzi (BTNWU).        Text); }        Private voidBtnliu_click (Objectsender, EventArgs e) {Jiashuzi (Btnliu).        Text); }        Private voidBtnqi_click (Objectsender, EventArgs e) {Jiashuzi (Btnqi).        Text); }        Private voidBtnba_click (Objectsender, EventArgs e) {Jiashuzi (BTNBA).        Text); }        Private voidBtnjiu_click (Objectsender, EventArgs e) {Jiashuzi (Btnjiu).        Text); }        #endregion        Private voidBtnclear_click (Objectsender, EventArgs e) {Txtshuru. Text="0"; }        Private voidBtndian_click (Objectsender, EventArgs e) {            if(Txtshuru. Text.contains (".") {Label1. Text="only one decimal point can be entered"; }            Else{Txtshuru. Text+="."; }        }
        #region= = Operator Click event = =Private voidBtnjia_click (Objectsender, EventArgs e) {Jiayunsuanfu (Btnjia).        Text); }        Private voidBtnjian_click (Objectsender, EventArgs e) {Jiayunsuanfu (Btnjian).        Text); }        Private voidBtncheng_click (Objectsender, EventArgs e) {Jiayunsuanfu (Btncheng).        Text); }        Private voidBtnchu_click (Objectsender, EventArgs e) {Jiayunsuanfu (Btnchu).        Text); }        Private voidBtnmo_click (Objectsender, EventArgs e) {Jiayunsuanfu (BTNMO).        Text); }        #endregion        Private voidBtnchexiao_click (Objectsender, EventArgs e) {Txtshuru. Text= Txtshuru. Text.substring (0, Txtshuru. Text.length-1); }    }}

3. Calculator (call function)