Question

我试图通过编写一个程序找到两个使系统达到平衡的值来学习C＃。我尝试了Do-While循环，但是由于while语句的值在Do语句内部，因此无法建立while语句。它只是说“变量在当前上下文中不存在”。我希望我有道理。

更新：完整的代码发布在下面。我尝试了while（true）语句，并添加了if-break语句。我真的不知道这是否是if-break语句的工作方式。循环不断进行下去。我尝试打印值，但从第一个循环开始，它已经满足条件。

下面是我的代码：

using System;
using System.Linq;

public class BoltCoord
{
    public double x1;
    public double y1;
}

public class Program
{
    public static void Main()
    {
        Console.Write("Number of Rows: ");
        int nrow = int.Parse(Console.ReadLine());

        Console.Write("Spacing of Rows: ");
        double srow = double.Parse(Console.ReadLine());

        Console.Write("Number of Columns: ");
        int ncol = int.Parse(Console.ReadLine());

        Console.Write("Spacing of Columns: ");
        double scol = double.Parse(Console.ReadLine());

        Console.Write("Eccentricity from CG: ");
        double ecc = double.Parse(Console.ReadLine());

        Console.Write("Rotation: ");
        double rot = double.Parse(Console.ReadLine());

        int totalbolts = nrow * ncol;

        var boltgroupCG = BoltCG(nrow, ncol, srow, scol); // bolt group cg from first bolt

        double[] xvaluesofbolts = new double[totalbolts]; //x-values of each bolt where first bolt is (0,0)
        for (int ctr = 0; ctr < totalbolts; ctr++)
        {
            xvaluesofbolts[ctr] = (ctr % ncol) * srow;
        }

        double[] yvaluesofbolts = new double[totalbolts]; //y-values of each bolt where first bolt is (0,0)
        for (int ctr = 1; ctr < totalbolts; ctr++)
        {
            yvaluesofbolts[ctr] = (ctr / ncol) * srow;
        }

        double[] FxOfBolts = new double[totalbolts];
        double[] FyOfBolts = new double[totalbolts];
        double[] MomOfBolts = new double[totalbolts];
        double[] XTransOfBolts = new double[totalbolts]; // Translated X
        double[] YTransOfBolts = new double[totalbolts]; // Translated Y

        double[] XLi = new double[totalbolts]; // Translated X
        double[] YLi = new double[totalbolts]; // Translated Y

        double[] BoltDist = new double[totalbolts]; // from IC
        double[] DeformBolts = new double[totalbolts];
        double[] ReactionForce = new double[totalbolts];
        double[] ReactionForceX = new double[totalbolts];
        double[] ReactionForceY = new double[totalbolts];
        double[] MomentBolt = new double[totalbolts];

        var IC = new BoltCoord(); // from CG

        double Px;
        double Py;
        double sumRx;
        double sumRy;
        double ctrX;
        double ctrY;

        do
        {
            for (ctrX = 0; ctrX < 50; ctrX = ctrX + 0.1)
            {
                for (ctrY = 0; ctrY < 50; ctrY = ctrY + 0.1)
                {
                    for (int El = 0; El < totalbolts; El++)
                    {
                        XTransOfBolts[El] = xvaluesofbolts[El] - boltgroupCG.x1;
                        YTransOfBolts[El] = yvaluesofbolts[El] - boltgroupCG.y1;
                        XLi[El] = XTransOfBolts[El] + ctrX;
                        YLi[El] = YTransOfBolts[El] + ctrY;
                        BoltDist[El] = Math.Sqrt(Math.Pow(XLi[El], 2) + Math.Pow(YLi[El], 2));

                        double MaxDist = BoltDist.Max();
                        // int MaxIndex = Array.IndexOf(BoltDist, MaxDist);
                        double delta = 0.34;
                        double Rult = 74;


                        DeformBolts[El] = delta * BoltDist[El] / MaxDist;
                        ReactionForce[El] = Rult * Math.Pow((1 - Math.Exp(-10 * DeformBolts[El])), 0.55);

                        ReactionForceX[El] = ReactionForce[El] * YLi[El] / BoltDist[El];
                        ReactionForceY[El] = ReactionForce[El] * XLi[El] / BoltDist[El];

                        MomentBolt[El] = ReactionForce[El] * BoltDist[El];

                        sumRx = ReactionForceX.Sum();
                        sumRy = ReactionForceY.Sum();
                        double sumMoment = MomentBolt.Sum();
                        double sumReax = ReactionForce.Sum();

                        double ro = (ecc + ctrX) * Math.Cos(Math.PI * rot / 180) + ctrY * Math.Sin(Math.PI * rot / 180);
                        Px = sumMoment / ro;
                        Py = Px * Math.Cos(Math.PI * rot / 180);

                        Console.WriteLine(Px + " " + sumRx + " " + Py + " " + sumRy); // tried printing the values to see if loop happens. 
                                                                                      // Px minus sumRx and Py minus sumRy are always less than 1000 but
                                                                                      // loop still continues?

                        if ((Px - sumRx <= 1000) && (Py - sumRy <= 1000))
                        {
                            break;
                        }

                    }
                }
            }
        } while (true); //((Px != sumRx) || (Py != sumRy));
    }

    public static BoltCoord BoltCG(int nrow, int ncol, double srow, double scol)
    {
         var BoltCGCoord = new BoltCoord
         {
             x1 = (ncol - 1) * scol * 0.5,
             y1 = (nrow - 1) * srow * 0.5
         };
         return BoltCGCoord;
    }
}

Answer 1

如果您更换

class BinColCtrl:
    # ``: BinColUI`` tells the IDE the type of ``view`` and ``self._view``
    def __init__(self, model, view: BinColUI):
        self._evaluate = model
        self._view = view
        self.calculateResult()

使用

while ((Px != sumRx) || (Py != sumRy))

代码可以编译吗？

否则，请确保在do-while循环开始之前声明了变量Px，Py，sumRx，sumRy。

while (true)

Answer 2

我将您的代码放入dotnetfiddle.net中，并将while语句更改为

时遇到的错误

while((Px != sumRx) || (Py != sumRy))

是Use of unassigned local variable 'Px'。为了避免出现此错误，您需要在开始循环之前为Px sumRx Py和sumRy分配一个值。在循环上方，您只需将初始化更改为

double Px = 0;
double Py = 0;
double sumRx = 0;
double sumRy = 0;
double ctrX = 0;
double ctrY = 0;

此外，您的break语句不起作用，因为break语句适用于当前循环块，该循环块是您最里面的for循环，因此您脱离了最里面的for循环，而不是脱离while循环。 / p>

Answer 3

为什么循环不断进行的一般答案是您的for循环将检查每个条件，这意味着即使第一次找到答案，它也会循环nrow * ncol次。假设在您运行的代码中没有注释掉该行。（而true则将永远循环下去）。

    } while (true); //((Px != sumRx) || (Py != sumRy));

其中的break语句摆脱了最里面的for循环。如果您想保持早期爆发，还需要为所有循环编写爆发逻辑。总的来说，这很丑陋，这是为什么嵌套循环和if语句变得非常丑陋的一个很好的例子。：）

希望有帮助。

Do-While循环，但是while语句的值在Do语句内部

3 个答案: