1、设置图片中控件的相关属性
2、编写代码本程序需要用到一些公共变量，例如用来接收操作数、运算结果，判断输入的是豸阏恢闲否为小数等，因此首先在代码的通用段声明以下变量：double num1, num2, result; // 操作数及运算结果bool decimalFlag; // 判断输入的是否为小数string myOperator; // 操作类型接下来编写一个名为“NumClick”的方法，单击数字按钮时，调用NumClick方法，将输入的数字追加到文本框中，代码如下：public void NumClick(int myNumber){ if (decimalFlag) // 输入小数 { txtReadout.Text =txtReadout.Text + myNumber; } else { if (txtReadout.Text =="0.") // 输入整数 { // 输入的是整数的个位数字 txtReadout.Text =myNumber + "."; } else { // 输入的不是整数的个位数字 txtReadout.Text =txtReadout.Text.Substring 0,txtReadout.Text.Length - 1) + myNumber + "."; } }}编写窗体的载入事件代码如下：private void Form1_Load(object sender, EventArgs e){ txtReadout.Text ="0."; // 指定文本框的对齐方式为右对齐 txtReadout.TextAlign =HorizontalAlignment.Right;}编写数字按钮【0】～【9】的单击事件代码如下：private void btnNum0_Click(object sender, EventArgs e){ NumClick(0);}private void btnNum1_Click(object sender, EventArgs e){ NumClick(1);}private void btnNum2_Click(object sender, EventArgs e){ NumClick(2);}private void btnNum3_Click(object sender, EventArgs e){ NumClick(3);}private void btnNum4_Click(object sender, EventArgs e){ NumClick(4);}private void btnNum5_Click(object sender, EventArgs e){ NumClick(5);}private void btnNum6_Click(object sender, EventArgs e){ NumClick(6);}private void btnNum7_Click(object sender, EventArgs e){ NumClick(7);}private void btnNum8_Click(object sender, EventArgs e){ NumClick(8);}private void btnNum9_Click(object sender, EventArgs e){ NumClick(9);}编写小数点按钮【.】的单击事件代码如下：private void btnDot_Click(object sender, EventArgs e){ decimalFlag = true; //输入小数点}编写复位按钮【C】的单击事件代码如下：private void btnC_Click(object sender, EventArgs e){ num1 = 0; num2 = 0; txtReadout.Text ="0.";}编写【+】、【-】、【*】、【/】按钮的单击事件代码如下：private void btnAdd_Click(object sender, EventArgs e){ myOperator ="add"; num1 = double.Parse(txtReadout.Text); txtReadout.Text ="0."; decimalFlag = false;}private void btnSub_Click(object sender, EventArgs e){ myOperator ="Sub"; num1 =double.Parse(txtReadout.Text); txtReadout.Text ="0."; decimalFlag = false;}private void btnMul_Click(object sender, EventArgs e){ myOperator ="Mul"; num1 =double.Parse(txtReadout.Text); txtReadout.Text ="0."; decimalFlag = false;}private void btnDiv_Click(object sender, EventArgs e){ myOperator ="Div"; num1 =double.Parse(txtReadout.Text); txtReadout.Text ="0."; decimalFlag = false;}最后编写【=】按钮的单击事件代码如下：private void btnAmount_Click(object sender, EventArgs e){ num2 =double.Parse(txtReadout.Text); switch (myOperator) { case "add": result = num1 +num2; txtReadout.Text =result.ToString(); break; case "Sub": result = num1 -num2; txtReadout.Text =result.ToString(); break; case "Mul": result = num1 *num2; txtReadout.Text =result.ToString(); break; case "Div": if (num2 == 0) { txtReadout.Text = "除数不能为“0”!"; } else { result = num1/ num2; txtReadout.Text = result.ToString(); } break; }}
3、运行结果运行程序，计算加法“23 ＋ 1.8”
4、单击【C】按钮，再计算加法“2.3 － 18”
5、单击【C】按钮，再计算加法“2.3 × 1.8”
6、单击【C】按钮，再计算加法“23.18 ÷ 0”
7、单击【C】按钮，再计算加法“2.3 ÷ 1.8”
