解析CSV文件中的数据

Question

Like in title I have problem with parsing data from CVS files. When i choose file with diffrent formating all i get is "Input string was not in a correct format". My code works with files formatted like that:

16.990750 4.0
17.000250 5.0
17.009750 1.0
17.019250 6.0

But cant handle files formatted like this one:

Series1 - X;Series1 - Y;
285.75;798
285.79;764
285.84;578
285.88;690

This is code responsibile for reading data from file and creating chart from it:

if (openFileDialog1.ShowDialog() == DialogResult.OK)
        {
            string cos = File.ReadAllText(openFileDialog1.FileName);
            string[] rows = cos.Split(new string[] { "\r\n" }, StringSplitOptions.RemoveEmptyEntries);

            DataTable table = new DataTable();
            table.Columns.Add("xValue", typeof(decimal));
            table.Columns.Add("yValue", typeof(decimal));

            foreach (string row in rows)
            {
                string[] values = row.Split(' ');
                DataRow ch = table.NewRow();
                ch[0] = Decimal.Parse(values[0], NumberStyles.AllowDecimalPoint, CultureInfo.InvariantCulture);
                ch[1] = Decimal.Parse(values[1], NumberStyles.AllowDecimalPoint, CultureInfo.InvariantCulture);
                table.Rows.Add(ch);

            }
            if (seria == false)
            {
                wykres.Series.Add("series");
                wykres.Series["series"].ChartType = System.Windows.Forms.DataVisualization.Charting.SeriesChartType.Line;
                wykres.Series["series"].XValueMember = "xValue";
                wykres.Series["series"].YValueMembers = "yValue";
                wykres.DataSource = table;
                wykres.DataBind();

                seria = true;



            }
         }

EDIT

I changed parsing method to this one:

                foreach (string row in rows)
            {
                var values = row.Split(';');
                var ch = table.NewRow();
                decimal num = 0;
                if (decimal.TryParse(values[0], out num))
                    ch[0] = num;
                if (decimal.TryParse(values[1], out num))
                    ch[1] = num;
                table.Rows.Add(ch);
            }

It works okay but with one exception - It can't read decimals only integers from csv file(see the picture below).

View of table in locals

Why is this happening?

Answer 1

I suggest you don't re-invent the wheel, but use some well-tested library to parse the CSV (for example, your implementation does not handle quoted values well. It also doesn't allow the separator as part of a value).

And guess what: .NET includes something that could help you: the TextFieldParser class. Don't worry about the VisualBasic namespace - it works in C#, too :-)

Answer 2

foreach (string row in rows)
            {
                var values = row.Split(';');
                var ch = table.NewRow();
                decimal num = 0;
                if (decimal.TryParse(values[0], out num))
                    ch[0] = num;
                if (decimal.TryParse(values[1], out num))
                    ch[1] = num;
                table.Rows.Add(ch);
            }

In the second text format the separator is(;) and first row of the text has two strings therefore to convert a string to decimal use decimal.TryParse() instead of decimal.Parse().the return type of method TryParse() is boolean therefore if it returned true that means the string converted successful .