从.txt文件导入x和y坐标

Question

I need to read coordinates from text file for my project,but the text file is like this

1 37.4393516691 541.2090699418

2 612.1759508571 494.3166877396

3 38.1312338227 353.1484581781

and with more space in front.I have code that i tried but i couldn't make the seperators work.

      1    1150.0  1760.0

      2     630.0  1660.0

      3      40.0  2090.0

The code:

 string[] cityPositions = File.ReadAllLines(ofd.FileName);
                foreach (string cityP in cityPositions)
                {
                    int startIndexX = cityP.IndexOf("  ", StringComparison.CurrentCultureIgnoreCase) + 3;
                    int endIndexX = cityP.IndexOf(" ", StringComparison.CurrentCultureIgnoreCase);
                    int X = int.Parse(cityP.Substring(startIndexX, endIndexX - startIndexX));

                    int startIndexY = cityP.IndexOf(" ", StringComparison.CurrentCultureIgnoreCase) + 3;
                    int endIndexY = cityP.IndexOf("", StringComparison.CurrentCultureIgnoreCase);
                    int Y = int.Parse(cityP.Substring(startIndexY, endIndexY - startIndexY));
                    create_City(new Point(X, Y));
                }

Answer 1

First of all your data type doesnt match. You should use double for coordinates, and use Split method, for example:

double X = double.Parse(cityP.Split()[1], CultureInfo.InvariantCulture);
double Y = double.Parse(cityP.Split()[2], CultureInfo.InvariantCulture);

Split function with no parameters given will split by whitespace.

EDIT

It's not clear in the question but, if your lines dont have the same pattern, and have different spaces use Split method like this:

double X = double.Parse(cityP.Split(new[] { ' ' }, StringSplitOptions.RemoveEmptyEntries)[1], CultureInfo.InvariantCulture);

Answer 2

If you want to make use of Regular Expressions, try this:

        String expression = @"(\d)([\d\.]*)([\d\.]*)";

        Regex r = new Regex(expression);

        foreach (String cityPosition in cityPositions)
        {
            MatchCollection mc = r.Matches(cityPosition);
            int index = Convert.ToInt32(mc[0].Value);
            decimal coOrdX = Convert.ToDecimal(mc[1].Value);
            decimal coOrdY = Convert.ToDecimal(mc[2].Value);

            Console.WriteLine(String.Format("{0} {1} {2}", index, coOrdX, coOrdY));
        }

This code will produce this output:

1 1150.0 1760.0
2 630.0 1660.0
3 40.0 2090.0

It should disregard the varying amount of space between the values and make it easier to parse the three different values in the file.

Answer 3

Instead of working with indices, you could Replace multiple whitespaces with a single whitespace, like

    RegexOptions options = RegexOptions.None;
    Regex regex = new Regex("[ ]{2,}", options);     
    cityP = regex.Replace(cityP, " ");

then use split to get the coordinates

    var x = double.Parse(cityP.Split()[1]);
    var y = double.Parse(cityP.Split()[2]);