講四則運(yùn)算計(jì)算器二.ppt

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：/visualc/,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(xiě)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 = (Button)(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(xiě)“+、-、*、/、=”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 = double.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.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; txtOutput.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(xiě)操作符鍵“退格-、CE、C、sqrt、%、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 != “) 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