public static Operation choose(string s)
{
switch (s)
{
case "+":
oper = new OperationAdd();
break;
case "-":
oper = new OperationMinus();
break;
case "*":
oper = new OperationRide();
break;
case "/":
oper = new OperationDiv();
break;
}
return(s);
}
private void btnCount_Click(object sender, EventArgs e)
{
if (txtNum1.Text.Trim().Equals(string.Empty))
{
MessageBox.Show("操作数不能为空！");
this.txtNum1.Focus();
return;
}
if (txtNum2.Text.Trim().Equals(string.Empty))
{
MessageBox.Show("被操作数不能为空！");
this.txtNum2.Focus();
return;
}
try
{
string s = this.cbxSign.SelectedItem.ToString().Trim();
Operation oper = new Operation();
switch (s)
{
case "+":
oper = new OperationAdd();
break;
case "-":
oper = new OperationMinus();
break;
case "*":
oper = new OperationRide();
break;
case "/":
oper = new OperationDiv();
break;
}
oper.NumberA = double.Parse(this.txtNum1.Text.Trim());
oper.NumberB = double.Parse(this.txtNum2.Text.Trim());
this.lblResult.Text = oper.GetReault().ToString();
}
catch (Exception ex)
{
MessageBox.Show(ex.ToString());
}
}