“Microsoft.VisualBasic.FileIO 不存在”。 如何在我的项目中包含这个库？

Question

So I am trying to parse a.csv file with columns that may include their own comma characters.

Answers here and here say that the best way to easily handle this without writing my own line-by-line parser would be to use the Microsoft.VisualBasic.FileIO library.

Unfortunately, when i try to include this in my project I get the common error:

'File.IO' does not exist in the namespace "Microsoft.VisualBasic" (are you missing an assembly reference?)

Fixes for this issue here and here all say that I need to use the Reference Manager to add Microsoft.VisualBasic to my project, but my reference manager does not have the Assemblies, with Framework and Extensions subgroups tabs that the official help documents say to use to add the package to my project. I have attached a screenshot of my Reference Manager window here. The Projects tab just shows a list of all the projects in my solution and the Shared Projects tab is blank.

I have also checked to see if I should include a NuGet package instead, but that did not solve the problem at all.

Answer 1

I ended up using the CSVHelper library which installs fine with NuGet and handled the comma-contained columns perfectly and even could be configured to ignore blank lines and headers.

I do not know why VisualBasic.FileIO could not be added to my project, why the best solutions from 6+ years ago said to use this library, or why my Reference Manager window is different from what official help says it should be, but I solved my root problem so here's hoping I don't actually need to use the Reference Manager in the future for anything.

Answer 2

I find the solution for solving the problem.

First, please change your platform from .net core2.1 to .net core3.0 or.net core 3.1.

Second, you can refer to the following code to convert csv file to datatable by using

Microsoft.VisualBasic.FileIO.

static void Main(string[] args)
        {
            DataTable table = GetDataTabletFromCSVFile("D:\\Test.csv");
        }

        private static DataTable GetDataTabletFromCSVFile(string csv_file_path)
        {
            DataTable csvData = new DataTable();
            try
            {
                using (TextFieldParser csvReader = new TextFieldParser(csv_file_path))
                {
                    csvReader.SetDelimiters(new string[] { "," });
                    csvReader.HasFieldsEnclosedInQuotes = true;
                    string[] colFields = csvReader.ReadFields();
                    foreach (string column in colFields)
                    {
                        if (column == "Name" || column == "Age" || column == "Id")
                        {
                            DataColumn datecolumn = new DataColumn(column);
                            datecolumn.AllowDBNull = true;
                            csvData.Columns.Add(datecolumn);
                        }
                    }
                    while (!csvReader.EndOfData)
                    {
                        string[] fieldData = csvReader.ReadFields();
                        for (int i = 0; i < fieldData.Length; i++)
                        {
                            if (fieldData[i] == "")
                            {
                                fieldData[i] = null;
                            }
                        }
                        csvData.Rows.Add(fieldData);
                    }
                }

            }
            catch (Exception)
            {
                throw;
            }
            return csvData;
        }

Result: