用if语句从某一行重启程序？ [英] Restart program from a certain line with an if statement?

问题描述

任何人都可以帮助我从第46行重启我的程序，如果用户输入1（在评论之后，它表明下一个代码将要求用户输入2个输入）并且如果用户输入-1结束它。我想不出怎么做。我是C＃的新手，你能给予的任何帮助都会很棒！

could anyone help me restart my program from line 46 if the user enters 1 (just after the comment where it states that the next code is going to ask the user for 2 inputs) and if the user enters -1 end it. I cannot think how to do it. I'm new to C# any help you could give would be great!

class Program
{
    static void Main(string[] args)
    {

        //Displays data in correct Format

        List<float> inputList = new List<float>();
        TextReader tr = new StreamReader("c:/users/tom/documents/visual studio 2010/Projects/DistanceCalculator3/DistanceCalculator3/TextFile1.txt");
        String input = Convert.ToString(tr.ReadToEnd());
        String[] items = input.Split(',');
        Console.WriteLine("Point         Latitude        Longtitude       Elevation");

        for (int i = 0; i < items.Length; i++)
        {
            if (i % 3 == 0)
            {
                Console.Write((i / 3) + "\t\t");
            }

            Console.Write(items[i]);
            Console.Write("\t\t");

            if (((i - 2) % 3) == 0)
            {
                Console.WriteLine();
            }

        }

        Console.WriteLine();
        Console.WriteLine();


        // Ask for two inputs from the user which is then converted into 6 floats and transfered in class Coordinates    


        Console.WriteLine("Please enter the two points that you wish to know the distance between:");
        string point = Console.ReadLine();
        string[] pointInput = point.Split(' ');

        int pointNumber = Convert.ToInt16(pointInput[0]);
        int pointNumber2 = Convert.ToInt16(pointInput[1]);

        Coordinates distance = new Coordinates();

        distance.latitude = (Convert.ToDouble(items[pointNumber * 3]));
        distance.longtitude = (Convert.ToDouble(items[(pointNumber * 3) + 1]));
        distance.elevation = (Convert.ToDouble(items[(pointNumber * 3) + 2]));

        distance.latitude2 = (Convert.ToDouble(items[pointNumber2 * 3]));
        distance.longtitude2 = (Convert.ToDouble(items[(pointNumber2 * 3) + 1]));
        distance.elevation2 = (Convert.ToDouble(items[(pointNumber2 * 3) + 2]));


        //Calculate the distance between two points

        const double PIx = 3.141592653589793;
        const double RADIO = 6371;

        double dlat = ((distance.latitude2) * (PIx / 180)) - ((distance.latitude) * (PIx / 180));
        double dlon = ((distance.longtitude2) * (PIx / 180)) - ((distance.longtitude) * (PIx / 180));

        double a = (Math.Sin(dlat / 2) * Math.Sin(dlat / 2)) + Math.Cos((distance.latitude) * (PIx / 180)) * Math.Cos((distance.latitude2) * (PIx / 180)) * (Math.Sin(dlon / 2) * Math.Sin(dlon / 2));
        double angle = 2 * Math.Atan2(Math.Sqrt(a), Math.Sqrt(1 - a));
        double ultimateDistance = (angle * RADIO);

        Console.WriteLine("The distance between your two points is...");
        Console.WriteLine(ultimateDistance);

        //Repeat the program if the user enters 1, end the program if the user enters -1

        Console.WriteLine("If you wish to calculate another distance type 1 and return, if you wish to end the program, type -1.");
        Console.ReadLine();

        if (Convert.ToInt16(Console.ReadLine()) == 1);

        {
           //here is where I need it to repeat
        }

推荐答案

bool exit = false;
do
{
    Console.WriteLine("Please enter the two points that you wish to know the distance between:");
    ...
    Console.WriteLine("If you wish to calculate another distance type 1 and return, if you wish to end the program, type -1.");

    string input;

    do
    {
        input = Console.ReadLine().Trim();
    }
    while (input != "1" && input != "-1");

    if (input == -1) exit = true;
}
while (!exit);

但是你会更好地考虑将逻辑推入方法和函数，以便你编写程序积累更小的积木。

But you would do much better to think about pushing logic into methods and functions such that you program is built up of much smaller building blocks.

你应该瞄准这样的事情：

You should be aiming towards something like this:

bool exit = false;
do
{
    Point[] points = ReadCoordinates();
    Whatever result = CalculateWhatever();
    DisplayResults(results);

    exit = ShouldExit();
}
while (!exit);

这使得程序的外循环自我记录并且方法不言自明。

This makes the outer loop of your program self documenting and the methods self explanatory.

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