c# 将csv文件转换datatable的三种方式。

第一种：

public static DataTable csvdatatable(string path)
{
DataTable dt = new DataTable();
string connectionString = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + path + ";" + "Extended Properties='Excel 12.0 Xml;HDR=YES;IMEX=1;MAXSCANROWS=0'"using (OleDbConnection conn = new OleDbConnection(connectionString))
{
using (OleDbCommand comm = new OleDbCommand())
{
string sheetName = "Sheet1";
comm.CommandText = "Select * from [" + sheetName + "$]";
comm.Connection = conn;
using (OleDbDataAdapter da = new OleDbDataAdapter())
{
da.SelectCommand = comm;
da.Fill(dt);
return dt;
}
}

}
}

第二种:

需要引用    

Microsoft.VisualBasic.dll

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 == "Date" || column == "Test1" || column == "USL" || column == "LSL")
{
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;
}

 第三种 需要引用

Microsoft.Office.Interop.Excel

      public DataTable READExcel(string path)
        {
            Microsoft.Office.Interop.Excel.Application objXL = null;
            Microsoft.Office.Interop.Excel.Workbook objWB = null;
            objXL = new Microsoft.Office.Interop.Excel.Application();
            objWB = objXL.Workbooks.Open(path);
            Microsoft.Office.Interop.Excel.Worksheet objSHT = objWB.Worksheets[1];

            int rows = objSHT.UsedRange.Rows.Count;
            int cols = objSHT.UsedRange.Columns.Count;
            DataTable dt = new DataTable();
            int noofrow = 1;

            for (int c = 1; c <= cols; c++)
            {
                string colname = objSHT.Cells[1, c].Text;
                dt.Columns.Add(colname);
                noofrow = 2;
            }

            for (int r = noofrow; r <= rows; r++)
            {
                DataRow dr = dt.NewRow();
                for (int c = 1; c <= cols; c++)
                {
                    dr[c - 1] = objSHT.Cells[r, c].Text;
                }

                dt.Rows.Add(dr);
            }

            objWB.Close();
            objXL.Quit();
            return dt;
        }