我的汽车租赁计划 2 C#

我需要汽车程序的帮助。我试图做到这一点，当你点击汽车单选按钮时，假设我想要一辆布加迪，我会点击布加迪单选按钮，它会通过以下代码计算最终成本：

bugattiDecimal = bugattiFinal * (Decimal)0.20 + rentedDecimal * 25;

该代码应该计算每英里0.20美元和每天租用25美元。

这是代码的其余部分：

//Step 3: Mathmatematical Calculations.
totalMilesDecimal = endingOdometerDecimal - beginningOdometerDecimal;
lamborghiniFinal = endingOdometerDecimal - beginningOdometerDecimal;
ferrariFinal = endingOdometerDecimal - beginningOdometerDecimal;
bugattiFinal = endingOdometerDecimal - beginningOdometerDecimal;
lamborghiniDecimal = lamborghiniFinal * (Decimal)0.12 + rentedDecimal * 15;
ferrariDecimal = ferrariFinal * (Decimal)0.15 + rentedDecimal * 20;
bugattiDecimal = bugattiFinal * (Decimal)0.20 + rentedDecimal * 25;
//This  shows the picture.
if (radLamborghini.Checked) {
   picLamborghini.Visible = true;
   picFerrari.Visible = false;
   picBugatti.Visible = false;
}
if (radLamborghini.Checked) {
   lblFinalCost.Text = lamborghiniDecimal.ToString();
}
private void radFerrari_CheckedChanged(object sender, EventArgs e)
{
   //This shows the picture.
   if (radFerrari.Checked) {
      picFerrari.Visible = true;
      picLamborghini.Visible = false;
      picBugatti.Visible = false;
   }
   if (radFerrari.Checked) {
      lblFinalCost.Text = ferrariDecimal.ToString();
   }
}
private void radBugatti_CheckedChanged(object sender, EventArgs e)
{
   //This shows the picture.
   if (radBugatti.Checked) {
      picBugatti.Visible = true;
      picLamborghini.Visible = false;
      picFerrari.Visible = false;
   }
   if (radBugatti.Checked) {
      lblFinalCost.Text = bugattiDecimal.ToString();
   }
}

我的代码正确吗？当我单击其中一个单选按钮时，它们都计算相同的成本。