三講四則運(yùn)算計(jì)算器二

1、第三講 四則運(yùn)算計(jì)算器（二）教育部“十二五”職業(yè)教育國(guó)家規(guī)劃教材 Visual C#程序設(shè)計(jì)與軟件項(xiàng)目實(shí)訓(xùn)電子工業(yè)出版社 鄭偉 譚恒松 編著ISBN:9787121246128 教材網(wǎng)站： 目錄任務(wù)：設(shè)計(jì)復(fù)雜四則運(yùn)算計(jì)算器 任務(wù)：功能拓展 任務(wù)：設(shè)計(jì)復(fù)雜四則運(yùn)算計(jì)算器任務(wù)：設(shè)計(jì)復(fù)雜四則運(yùn)算計(jì)算器代碼1首先定義窗體的公共變量string str, opp, opp1;double num1, num2, result;2編寫數(shù)字鍵的單擊事件，數(shù)字鍵“0-9”的事件都是一個(gè)private void number(object sender, EventArgs e) Button b = (But

2、ton)(sender);/實(shí)例化按鈕對(duì)象 str = b.Text; if (txtOutput.Text = 0)/判斷是否按下為0的按鈕 txtOutput.Text = str; else txtOutput.Text = txtOutput.Text + str;任務(wù)：設(shè)計(jì)復(fù)雜四則運(yùn)算計(jì)算器代碼3編寫“+、-、*、/、=”操作符鍵的單擊事件 private void operator1(object sender, EventArgs e) Button b = (Button)(sender);/實(shí)例化按鈕對(duì)象 if (b.Text = +)/判斷是否按下加號(hào) num1 = dou

3、ble.Parse(txtOutput.Text); txtOutput.Text = ; opp = +; opp1 = ; else if (b.Text = -)/判斷是否按下減號(hào) num1 = double.Parse(txtOutput.Text); txtOutput.Text = ; opp = -; opp1 = ; 任務(wù)：設(shè)計(jì)復(fù)雜四則運(yùn)算計(jì)算器代碼 else if (b.Text = *)/判斷是否按下乘號(hào) num1 = double.Parse(txtOutput.Text); txtOutput.Text = ; opp = *; opp1 = ; else if (b.

4、Text = /)/判斷是否按下除號(hào) num1 = double.Parse(txtOutput.Text); txtOutput.Text = ; opp = /; opp1 = ; 任務(wù)：設(shè)計(jì)復(fù)雜四則運(yùn)算計(jì)算器代碼 else if (b.Text = =)/判斷是否按下等號(hào) if (opp1 != =) num2 = double.Parse(txtOutput.Text); if (opp = +) num1 = num1 + num2; txtOutput.Text = + num1.ToString(); else if (opp = -) num1 = num1 - num2; t

5、xtOutput.Text = + num1.ToString(); 任務(wù)：設(shè)計(jì)復(fù)雜四則運(yùn)算計(jì)算器代碼 else if (opp = *) num1 = num1 * num2; txtOutput.Text = + num1.ToString(); else if (opp = /) if (num2 = 0)/判斷第二個(gè)數(shù)是否為零 txtOutput.Text = 除數(shù)不能為零; else num1 = num1 / num2; txtOutput.Text = + num1.ToString(); opp1 = =; 任務(wù)：設(shè)計(jì)復(fù)雜四則運(yùn)算計(jì)算器代碼4編寫操作符鍵“退格-、CE、C、sq

6、rt、%、1/x、+/-、.”等按鈕的單擊事件 private void operator2(object sender, EventArgs e) Button b = (Button)(sender);/實(shí)例化按鈕對(duì)象 if (b.Text = .)/判斷是否按下點(diǎn) str = txtOutput.Text; int index = str.IndexOf(.); if (index = -1) txtOutput.Text = str + .; 任務(wù)：設(shè)計(jì)復(fù)雜四則運(yùn)算計(jì)算器代碼 else if (b.Text = 退格-)/判斷是否按下退格符 if (txtOutput.Text !=

7、) str = txtOutput.Text; str = str.Substring(0, str.Length - 1); txtOutput.Text = str; else if (b.Text = CE)/判斷是否按下CE txtOutput.Text = 0; 任務(wù)：設(shè)計(jì)復(fù)雜四則運(yùn)算計(jì)算器代碼 else if (b.Text = C)/判斷是否按下C result = num1 = num2 = 0; str = null; opp = null; txtOutput.Text = 0; else if (b.Text = sqrt)/判斷是否按下sqrt num1 = double.Parse(txtOutput.Text); result = Math.Sqrt(num1); txtOutput.Text = result.ToString(); 任務(wù)：設(shè)計(jì)復(fù)雜四則運(yùn)算計(jì)算器代碼 else if (b.Text = 1/x)/判斷是否按下1/x num1 = double.Parse(txtOutput.Text); result = 1 / num1; txtOutput.Text = result.ToString(); else if (b.Text = %)/判斷是否