C# 无法让运算符使用小数和双精度运算，但我需要它。有没有办法在不重做整个代码的情况下解决这个问题？

你好!！我在试图让我的代码正确执行总计时遇到问题。我发现错误运算符“+”不能应用于第行的“double”和“decimal”类型的操作数：

namespace JoesAutomotive
{
public partial class frmAutomotive : Form
{
    public frmAutomotive()
    {
        InitializeComponent();
    }

    // i want to take each group box, and make them a reference.
    private double OilandLubeCosts()
    {
        double OilLubeTotal = 0; //default value for the total in the groupbox.
        {
            if (chkOilChange.Checked)  // if user wants an Oil Change for $28
            {
                OilLubeTotal += 26.00;
                lblServiceandLabor.Text = OilLubeTotal.ToString("C");
            }
            if (chkLubeJob.Checked) // if user wants Lube Job for $18.00     // if user wants both, then it simply adds onto totals.
            {
                OilLubeTotal += 18.00;
                lblServiceandLabor.Text = OilLubeTotal.ToString("C");
                return OilLubeTotal;    // return the checked amounts by adding and sending to OilandLubeCharges.
            }
            else
            {
                return OilLubeTotal; // return values even if none are checked.
            }
        }

    }
    private double FlushCosts()
    {
        double FlushTotal = 0;
        {
            if (chkRadiator.Checked)
            {
                FlushTotal += 30.00;
                lblServiceandLabor.Text = FlushTotal.ToString("C");
            }
            if (chkTransmission.Checked)
            {
                FlushTotal += 80.00;
                lblServiceandLabor.Text = FlushTotal.ToString("C");
                return FlushTotal;
            }
            else
            {
                return FlushTotal;
            }
        }
    }
    private double MiscCosts()
    {
        double MiscTotal = 0;
        {
            if (chkInspection.Checked)
            {
                MiscTotal += 15.00;
                lblServiceandLabor.Text = MiscTotal.ToString("C");
            }
            if (chkReplaceMuffler.Checked)
            {
                MiscTotal += 100.00;
                lblServiceandLabor.Text = MiscTotal.ToString("C");
            }
            if (chkTireRotation.Checked)
            {
                MiscTotal += 20.00;
                lblServiceandLabor.Text = MiscTotal.ToString("C");
                return MiscTotal;
            }
            else
            {
                return MiscTotal;
            }
        }
    }
    private double PartsandLaborCharges()
    {
        double OtherCharges = 0;

        {

            if (double.TryParse(txtLabor.Text, out double LaborCost))
            {
                lblServiceandLabor.Text = LaborCost.ToString("C");
                // exception handling! If the user types in the labor textbox and receives an error out of Labor Costs, throw error.

                OtherCharges = LaborCost;
            }
        }
        if (double.TryParse(txtParts.Text, out double PartsCost))
        {
            lblServiceandLabor.Text = PartsCost.ToString("C");
            OtherCharges = PartsCost;           // we want our output to be based on PartsCost as well.
            return OtherCharges;                    // we take everything we added to our bill and sent the numbers back to our Other Charges.
        }
        else
        {
            return OtherCharges;
        }
    }
    private decimal Taxes()
    {
        decimal PlusTaxes;
        decimal PartsBought = Convert.ToDecimal(txtParts.Text);

        PlusTaxes = PartsBought * 0.06m;
        lblTaxonParts.Text = PlusTaxes.ToString("C");
        // Have to use decimal because we cannot convert. m = money. So cents.
        return PlusTaxes; // take the added price and sent back to reference.
    }
    private decimal TotalAmountCharged()
    {
        decimal TotalServiceFee;

        TotalServiceFee = OilandLubeCosts() + MiscCosts() + FlushCosts() + PartsandLaborCharges() + Taxes();
        //we take everything added up and apply to Total for complete pricing.
        lblTotalFees.Text = TotalServiceFee.ToString("C");
        return TotalServiceFee;
    }


    private void BtnCalculate_Click(object sender, EventArgs e)
    {
        OilandLubeCosts(); 
        FlushCosts();
        MiscCosts();
        PartsandLaborCharges();
        Taxes();                               // we want to take what we called up there, get totals, and display when we press calculate.
    }



}
}

---

看看我的代码，我必须把所有东西都转换成Int？我试着弄乱我的代码，把所有的代码都改成十进制，或者把所有的代码都改成双精度，但是我得到了很多错误。有没有办法解决这个问题而不必重做整个表单？谢谢大家!

去掉double，用decimal替换，它更适合您的任务

TotalServiceFee = OilandLubeCosts() + MiscCosts() + FlushCosts() + 
PartsandLaborCharges() + Taxes();

---

您的Taxes函数返回十进制数，其中其他值为double，而您的TotalServiceFee假定为double。我认为您的parts和LaborCharges方法中也可能存在错误。如果有零件成本，它将替换人工成本。@Kajal我已经修复了这两个成本，仍然会得到错误代码……去掉double，用decimal替换，它更适合您的任务。

   private decimal OilandLubeCosts()
    {
        decimal OilLubeTotal = 0; //default value for the total in the groupbox.
        {
            if (chkOilChange.Checked)  // if user wants an Oil Change for $28
            {
                OilLubeTotal += 26.00m;
                lblServiceandLabor.Text = OilLubeTotal.ToString("C");
            }
            if (chkLubeJob.Checked) // if user wants Lube Job for $18.00     // if user wants both, then it simply adds onto totals.
            {
                OilLubeTotal += 18.00m;
                lblServiceandLabor.Text = OilLubeTotal.ToString("C");
                return OilLubeTotal;    // return the checked amounts by adding and sending to OilandLubeCharges.
            }
            else
            {
                return OilLubeTotal; // return values even if none are checked.
            }
        }

    }
    private decimal FlushCosts()
    {
        decimal FlushTotal = 0;
        {
            if (chkRadiator.Checked)
            {
                FlushTotal += 30.00m;
                lblServiceandLabor.Text = FlushTotal.ToString("C");
            }
            if (chkTransmission.Checked)
            {
                FlushTotal += 80.00m;
                lblServiceandLabor.Text = FlushTotal.ToString("C");
                return FlushTotal;
            }
            else
            {
                return FlushTotal;
            }
        }
    }
    private decimal MiscCosts()
    {
        decimal MiscTotal = 0;
        {
            if (chkInspection.Checked)
            {
                MiscTotal += 15.00m;
                lblServiceandLabor.Text = MiscTotal.ToString("C");
            }
            if (chkReplaceMuffler.Checked)
            {
                MiscTotal += 100.00m;
                lblServiceandLabor.Text = MiscTotal.ToString("C");
            }
            if (chkTireRotation.Checked)
            {
                MiscTotal += 20.00m;
                lblServiceandLabor.Text = MiscTotal.ToString("C");
                return MiscTotal;
            }
            else
            {
                return MiscTotal;
            }
        }
    }
    private decimal PartsandLaborCharges()
    {
        decimal OtherCharges = 0;

        {

            if (decimal.TryParse(txtLabor.Text, out decimal LaborCost))
            {
                lblServiceandLabor.Text = LaborCost.ToString("C");
                // exception handling! If the user types in the labor textbox and receives an error out of Labor Costs, throw error.

                OtherCharges = LaborCost;
            }
        }
        if (decimal.TryParse(txtParts.Text, out decimal PartsCost))
        {
            lblServiceandLabor.Text = PartsCost.ToString("C");
            OtherCharges = PartsCost;           // we want our output to be based on PartsCost as well.
            return OtherCharges;                    // we take everything we added to our bill and sent the numbers back to our Other Charges.
        }
        else
        {
            return OtherCharges;
        }
    }
    private decimal Taxes()
    {
        decimal PlusTaxes;
        decimal PartsBought = Convert.ToDecimal(txtParts.Text);

        PlusTaxes = PartsBought * 0.06m;
        lblTaxonParts.Text = PlusTaxes.ToString("C");
        // Have to use decimal because we cannot convert. m = money. So cents.
        return PlusTaxes; // take the added price and sent back to reference.
    }
    private decimal TotalAmountCharged()
    {
        decimal TotalServiceFee;

        TotalServiceFee = OilandLubeCosts() + MiscCosts() + FlushCosts() + PartsandLaborCharges() + Taxes();
        //we take everything added up and apply to Total for complete pricing.
        lblTotalFees.Text = TotalServiceFee.ToString("C");
        return TotalServiceFee;
    }


    private void BtnCalculate_Click(object sender, EventArgs e)
    {
        OilandLubeCosts();
        FlushCosts();
        MiscCosts();
        PartsandLaborCharges();
        Taxes();                               // we want to take what we called up there, get totals, and display when we press calculate.
    }