Currently have a DataTable, but wish to stream it to the user via a WebHandler. FileHelpers has CommonEngine.DataTableToCsv(dt, "file.csv"). However it saves it to a file. How can I save it to a stream instead? I know how to do it when I know the columns in advanced or they don't change, but I want to generate the column headings straight from the data table.
If I know the columns I just create the class:
[DelimitedRecord(",")]
public class MailMergeFields
{
[FieldQuoted()]
public string FirstName;
[FieldQuoted()]
public string LastName;
}
Then use FileHelperEngine and add the records:
FileHelperEngine engine = new FileHelperEngine(typeof(MailMergeFields));
MailMergeFields[] merge = new MailMergeFields[dt.Rows.Count + 1];
// add headers
merge[0] = new MailMergeFields();
merge[0].FirstName = "FirstName";
merge[0].LastName = "LastName";
int i = 1;
// add records
foreach (DataRow dr in dt.Rows)
{
merge[i] = new MailMergeFields();
merge[i].FirstName = dr["Forename"];
merge[i].LastName = dr["Surname"];
i++;
}
Finally write to a stream:
TextWriter writer = new StringWriter();
engine.WriteStream(writer, merge);
context.Response.Write(writer.ToString());
Unfortunately as I don't know the columns before hand, I can't create the class before hand.
You can just write something quickly yourself:
public static class Extensions
{
public static string ToCSV(this DataTable table)
{
var result = new StringBuilder();
for (int i = 0; i < table.Columns.Count; i++)
{
result.Append(table.Columns[i].ColumnName);
result.Append(i == table.Columns.Count - 1 ? "\n" : ",");
}
foreach (DataRow row in table.Rows)
{
for (int i = 0; i < table.Columns.Count; i++)
{
result.Append(row[i].ToString());
result.Append(i == table.Columns.Count - 1 ? "\n" : ",");
}
}
return result.ToString();
}
}
And to test:
public static void Main()
{
DataTable table = new DataTable();
table.Columns.Add("Name");
table.Columns.Add("Age");
table.Rows.Add("John Doe", "45");
table.Rows.Add("Jane Doe", "35");
table.Rows.Add("Jack Doe", "27");
var bytes = Encoding.GetEncoding("iso-8859-1").GetBytes(table.ToCSV());
MemoryStream stream = new MemoryStream(bytes);
StreamReader reader = new StreamReader(stream);
Console.WriteLine(reader.ReadToEnd());
}
EDIT: Re your comments:
It depends on how you want your csv formatted but generally if the text contains special characters, you want to enclose it in double quotes ie: "my,text". You can add checking in the code that creates the csv to check for special characters and encloses the text in double quotes if it is. As for the .NET 2.0 thing, just create it as a helper method in your class or remove the word this in the method declaration and call it like so : Extensions.ToCsv(table);
Update 1
I have modified it to use StreamWriter instead, add an option to check if you need column headers in your output.
public static bool DataTableToCSV(DataTable dtSource, StreamWriter writer, bool includeHeader)
{
if (dtSource == null || writer == null) return false;
if (includeHeader)
{
string[] columnNames = dtSource.Columns.Cast<DataColumn>().Select(column => "\"" + column.ColumnName.Replace("\"", "\"\"") + "\"").ToArray<string>();
writer.WriteLine(String.Join(",", columnNames));
writer.Flush();
}
foreach (DataRow row in dtSource.Rows)
{
string[] fields = row.ItemArray.Select(field => "\"" + field.ToString().Replace("\"", "\"\"") + "\"").ToArray<string>();
writer.WriteLine(String.Join(",", fields));
writer.Flush();
}
return true;
}
As you can see, you can choose the output by initial StreamWriter, if you use
StreamWriter(Stream BaseStream), you can write csv into MemeryStream, FileStream, etc.
Origin
I have an easy datatable to csv function, it serves me well:
public static void DataTableToCsv(DataTable dt, string csvFile)
{
StringBuilder sb = new StringBuilder();
var columnNames = dt.Columns.Cast<DataColumn>().Select(column => "\"" + column.ColumnName.Replace("\"", "\"\"") + "\"").ToArray();
sb.AppendLine(string.Join(",", columnNames));
foreach (DataRow row in dt.Rows)
{
var fields = row.ItemArray.Select(field => "\"" + field.ToString().Replace("\"", "\"\"") + "\"").ToArray();
sb.AppendLine(string.Join(",", fields));
}
File.WriteAllText(csvFile, sb.ToString(), Encoding.Default);
}
If you can turn your datatable into an IEnumerable this should work for you...
Response.Clear();
Response.Buffer = true;
Response.AddHeader("content-disposition", "attachment;filename=FileName.csv");
Response.Charset = "";
Response.ContentType = "application/text";
Response.Output.Write(ExampleClass.ConvertToCSV(GetListOfObject(), typeof(object)));
Response.Flush();
Response.End();
public static string ConvertToCSV(IEnumerable col, Type type)
{
StringBuilder sb = new StringBuilder();
StringBuilder header = new StringBuilder();
// Gets all properies of the class
PropertyInfo[] pi = type.GetProperties();
// Create CSV header using the classes properties
foreach (PropertyInfo p in pi)
{
header.Append(p.Name + ",");
}
sb.AppendLine(header.ToString().Remove(header.Length));
foreach (object t in col)
{
StringBuilder body = new StringBuilder();
// Create new item
foreach (PropertyInfo p in pi)
{
object o = p.GetValue(t, null);
body.Append(o.ToString() + ",");
}
sb.AppendLine(body.ToString().Remove(body.Length));
}
return sb.ToString();
}
I don't know if this converted from VB to C# ok but if you don't want quotes around your numbers, you might compare the data type as follows..
public string DataTableToCSV(DataTable dt)
{
StringBuilder sb = new StringBuilder();
if (dt == null)
return "";
try {
// Create the header row
for (int i = 0; i <= dt.Columns.Count - 1; i++) {
// Append column name in quotes
sb.Append("\"" + dt.Columns[i].ColumnName + "\"");
// Add carriage return and linefeed if last column, else add comma
sb.Append(i == dt.Columns.Count - 1 ? "\n" : ",");
}
foreach (DataRow row in dt.Rows) {
for (int i = 0; i <= dt.Columns.Count - 1; i++) {
// Append value in quotes
//sb.Append("""" & row.Item(i) & """")
// OR only quote items that that are equivilant to strings
sb.Append(object.ReferenceEquals(dt.Columns[i].DataType, typeof(string)) || object.ReferenceEquals(dt.Columns[i].DataType, typeof(char)) ? "\"" + row[i] + "\"" : row[i]);
// Append CR+LF if last field, else add Comma
sb.Append(i == dt.Columns.Count - 1 ? "\n" : ",");
}
}
return sb.ToString;
} catch (Exception ex) {
// Handle the exception however you want
return "";
}
}
If you wish to stream the CSV out to the user without creating a file then I found the following to be the simplest method. You can use any extension/method to create the ToCsv() function (which returns a string based on the given DataTable).
var report = myDataTable.ToCsv();
var bytes = Encoding.GetEncoding("iso-8859-1").GetBytes(report);
Response.Buffer = true;
Response.Clear();
Response.AddHeader("content-disposition", "attachment; filename=report.csv");
Response.ContentType = "text/csv";
Response.BinaryWrite(bytes);
Response.End();
I've used the following code, pillaged from someone's blog (pls forgive lack of citation). It takes care of quotations, newline and comma in a reasonably elegant way by quoting out each field value.
/// <summary>
/// Converts the passed in data table to a CSV-style string.
/// </summary>
/// <param name="table">Table to convert</param>
/// <returns>Resulting CSV-style string</returns>
public static string ToCSV(this DataTable table)
{
return ToCSV(table, ",", true);
}
/// <summary>
/// Converts the passed in data table to a CSV-style string.
/// </summary>
/// <param name="table">Table to convert</param>
/// <param name="includeHeader">true - include headers<br/>
/// false - do not include header column</param>
/// <returns>Resulting CSV-style string</returns>
public static string ToCSV(this DataTable table, bool includeHeader)
{
return ToCSV(table, ",", includeHeader);
}
/// <summary>
/// Converts the passed in data table to a CSV-style string.
/// </summary>
/// <param name="table">Table to convert</param>
/// <param name="includeHeader">true - include headers<br/>
/// false - do not include header column</param>
/// <returns>Resulting CSV-style string</returns>
public static string ToCSV(this DataTable table, string delimiter, bool includeHeader)
{
var result = new StringBuilder();
if (includeHeader)
{
foreach (DataColumn column in table.Columns)
{
result.Append(column.ColumnName);
result.Append(delimiter);
}
result.Remove(--result.Length, 0);
result.Append(Environment.NewLine);
}
foreach (DataRow row in table.Rows)
{
foreach (object item in row.ItemArray)
{
if (item is DBNull)
result.Append(delimiter);
else
{
string itemAsString = item.ToString();
// Double up all embedded double quotes
itemAsString = itemAsString.Replace("\"", "\"\"");
// To keep things simple, always delimit with double-quotes
// so we don't have to determine in which cases they're necessary
// and which cases they're not.
itemAsString = "\"" + itemAsString + "\"";
result.Append(itemAsString + delimiter);
}
}
result.Remove(--result.Length, 0);
result.Append(Environment.NewLine);
}
return result.ToString();
}
You can try using something like this.
In this case I used one stored procedure to get more data tables and export all of them
using CSV.
using System;
using System.Text;
using System.Data;
using System.Data.SqlClient;
using System.IO;
namespace bo
{
class Program
{
static private void CreateCSVFile(DataTable dt, string strFilePath)
{
#region Export Grid to CSV
// Create the CSV file to which grid data will be exported.
StreamWriter sw = new StreamWriter(strFilePath, false);
int iColCount = dt.Columns.Count;
// First we will write the headers.
//DataTable dt = m_dsProducts.Tables[0];
for (int i = 0; i < iColCount; i++)
{
sw.Write(dt.Columns[i]);
if (i < iColCount - 1)
{
sw.Write(";");
}
}
sw.Write(sw.NewLine);
// Now write all the rows.
foreach (DataRow dr in dt.Rows)
{
for (int i = 0; i < iColCount; i++)
{
if (!Convert.IsDBNull(dr[i]))
{
sw.Write(dr[i].ToString());
}
if (i < iColCount -1 )
{
sw.Write(";");
}
}
sw.Write(sw.NewLine);
}
sw.Close();
#endregion
}
static void Main(string[] args)
{
string strConn = "connection string to sql";
string direktorij = #"d:";
SqlConnection conn = new SqlConnection(strConn);
SqlCommand command = new SqlCommand("sp_ado_pos_data", conn);
command.CommandType = CommandType.StoredProcedure;
command.Parameters.Add('#skl_id', SqlDbType.Int).Value = 158;
SqlDataAdapter adapter = new SqlDataAdapter(command);
DataSet ds = new DataSet();
adapter.Fill(ds);
for (int i = 0; i < ds.Tables.Count; i++)
{
string datoteka = (string.Format(#"{0}tablea{1}.csv", direktorij, i));
DataTable tabela = ds.Tables[i];
CreateCSVFile(tabela,datoteka );
Console.WriteLine("GeneriĊĦem tabelu {0}", datoteka);
}
Console.ReadKey();
}
}
}
public void CreateCSVFile(DataTable dt, string strFilePath,string separator)
{
#region Export Grid to CSV
// Create the CSV file to which grid data will be exported.
StreamWriter sw = new StreamWriter(strFilePath, false);
int iColCount = dt.Columns.Count;
for (int i = 0; i < iColCount; i++)
{
sw.Write(dt.Columns[i]);
if (i < iColCount - 1)
{
sw.Write(separator);
}
}
sw.Write(sw.NewLine);
// Now write all the rows.
foreach (DataRow dr in dt.Rows)
{
for (int i = 0; i < iColCount; i++)
{
if (!Convert.IsDBNull(dr[i]))
{
sw.Write(dr[i].ToString());
}
if (i < iColCount - 1)
{
sw.Write(separator);
}
}
sw.Write(sw.NewLine);
}
sw.Close();
#endregion
}
BFree's answer worked for me. I needed to post the stream right to the browser. Which I'd imagine is a common alternative. I added the following to BFree's Main() code to do this:
//StreamReader reader = new StreamReader(stream);
//Console.WriteLine(reader.ReadToEnd());
string fileName = "fileName.csv";
HttpContext.Current.Response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
HttpContext.Current.Response.AddHeader("content-disposition", string.Format("attachment;filename={0}", fileName));
stream.Position = 0;
stream.WriteTo(HttpContext.Current.Response.OutputStream);
Related
I am trying to export an excel and make it password protected.
My code is given below.
But i am getting error:
Excel completed file level validation and repair.
Some parts of this workbook may have been repaired or discarded.
I DON'T KNOW WHAT I AM DOING WRONG .
In-case i do it without the save As line for package then this error doesn't appear.
In my controller:
[HttpGet]
public FileStreamResult ExportToExcel()
{
_objService = new ServiceBAL();
List<ReconcilationEntity> Objmodel = new List<ReconcilationEntity>();
Objmodel = _objService.GetCreditsudharLeads();
String URL = string.Empty;
if (!Directory.Exists(Server.MapPath("~/TempExcel")))
{
System.IO.Directory.CreateDirectory(Server.MapPath("~/TempExcel"));
}
String Filepath = Server.MapPath("~/TempExcel");
string date = DateTime.Now.ToShortDateString().Replace("/", "_") + "_" + DateTime.Now.ToShortTimeString().Replace(" ", "_").Replace(":", "_").Trim();
String FileName = "Creditsudhar_" + date + ".xlsx";
Filepath = Filepath + "\\" + FileName;
string[] columns = { "AffName", "AffPhone", "AffEmail", "ProductName", "ContactName", "Status", "CreatedOn", "Commission", "IsCommissionPaid", "Accountname", "AccountNumber", "BankName", "BankBranch", "IFSCCode", "PanNumber" };
var file = ExcelExportHelper.ExportExcel(ExcelExportHelper.ListToDataTable(Objmodel), Filepath, "Creditsudhar Reconcillation Sheet " + DateTime.Now.ToShortDateString(), true, columns);
var memStream = new MemoryStream(file);
return this.File(memStream, "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet", FileName);
}
public static string ExcelContentType
{
get
{ return "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"; }
}
public static DataTable ListToDataTable<T>(List<T> data)
{
PropertyDescriptorCollection properties = TypeDescriptor.GetProperties(typeof(T));
DataTable dataTable = new DataTable();
for (int i = 0; i < properties.Count; i++)
{
PropertyDescriptor property = properties[i];
dataTable.Columns.Add(property.Name, Nullable.GetUnderlyingType(property.PropertyType) ?? property.PropertyType);
}
object[] values = new object[properties.Count];
foreach (T item in data)
{
for (int i = 0; i < values.Length; i++)
{
values[i] = properties[i].GetValue(item);
}
dataTable.Rows.Add(values);
}
return dataTable;
}
public static byte[] ExportExcel(DataTable dataTable, String Filepath, string heading = "", bool showSrNo = false, params string[] columnsToTake)
{
string fullPath = string.Empty;
byte[] ret;
DeleteUploadedFile(Filepath);
String result = String.Empty;
using (ExcelPackage package = new ExcelPackage())
{
ExcelWorksheet workSheet = package.Workbook.Worksheets.Add(String.Format("{0} Data", heading));
int startRowFrom = String.IsNullOrEmpty(heading) ? 1 : 3;
if (showSrNo)
{
DataColumn dataColumn = dataTable.Columns.Add("#", typeof(int));
dataColumn.SetOrdinal(0);
int index = 1;
foreach (DataRow item in dataTable.Rows)
{
item[0] = index;
index++;
}
}
// add the content into the Excel file
workSheet.Cells["A" + startRowFrom].LoadFromDataTable(dataTable, true);
// autofit width of cells with small content
int columnIndex = 1;
foreach (DataColumn column in dataTable.Columns)
{
try
{
ExcelRange columnCells = workSheet.Cells[workSheet.Dimension.Start.Row, columnIndex, workSheet.Dimension.End.Row, columnIndex];
int maxLength = columnCells.Max(cell => cell.Value.ToString().Count());
if (maxLength < 150)
{
workSheet.Column(columnIndex).AutoFit();
}
columnIndex++;
}
catch (Exception ex)
{
if (!(ex is System.Threading.ThreadAbortException))
{
//Log other errors here
}
}
}
// format header - bold, yellow on black
using (ExcelRange r = workSheet.Cells[startRowFrom, 1, startRowFrom, dataTable.Columns.Count])
{
r.Style.Font.Color.SetColor(System.Drawing.Color.White);
r.Style.Font.Bold = true;
r.Style.Fill.PatternType = OfficeOpenXml.Style.ExcelFillStyle.Solid;
r.Style.Fill.BackgroundColor.SetColor(System.Drawing.ColorTranslator.FromHtml("#1fb5ad"));
}
// format cells - add borders
using (ExcelRange r = workSheet.Cells[startRowFrom + 1, 1, startRowFrom + dataTable.Rows.Count, dataTable.Columns.Count])
{
r.Style.Border.Top.Style = ExcelBorderStyle.Thin;
r.Style.Border.Bottom.Style = ExcelBorderStyle.Thin;
r.Style.Border.Left.Style = ExcelBorderStyle.Thin;
r.Style.Border.Right.Style = ExcelBorderStyle.Thin;
r.Style.Border.Top.Color.SetColor(System.Drawing.Color.Black);
r.Style.Border.Bottom.Color.SetColor(System.Drawing.Color.Black);
r.Style.Border.Left.Color.SetColor(System.Drawing.Color.Black);
r.Style.Border.Right.Color.SetColor(System.Drawing.Color.Black);
}
// removed ignored columns
for (int i = dataTable.Columns.Count - 1; i >= 0; i--)
{
if (i == 0 && showSrNo)
{
continue;
}
if (!columnsToTake.Contains(dataTable.Columns[i].ColumnName))
{
workSheet.DeleteColumn(i + 1);
}
}
if (!String.IsNullOrEmpty(heading))
{
workSheet.Cells["A1"].Value = heading;
workSheet.Cells["A1"].Style.Font.Size = 20;
workSheet.InsertColumn(1, 1);
workSheet.InsertRow(1, 1);
workSheet.Column(1).Width = 5;
}
System.IO.FileInfo fileinfo2 = new System.IO.FileInfo(Filepath);
DeleteUploadedFile(Filepath);
workSheet.Protection.SetPassword("myPassword");
workSheet.Protection.IsProtected = true;
workSheet.Protection.AllowSelectUnlockedCells = false;
workSheet.Protection.AllowSelectLockedCells = false;
package.SaveAs(fileinfo2, "myPassword");
ret = package.GetAsByteArray();
return ret;
}
}
public static void DeleteUploadedFile(String filePath)
{
try
{
if (System.IO.File.Exists(filePath))
{
System.IO.File.Delete(filePath);
}
}
catch (Exception ex)
{ }
}
public static byte[] ExportExcel<T>(List<T> data, String Filepath, string Heading = "", bool showSlno = false, params string[] ColumnsToTake)
{
return ExportExcel(ListToDataTable<T>(data), Filepath, Heading, showSlno, ColumnsToTake);
}
An answer mentioned SaveAs close the package, so the correct steps will be returning the saved file as array instead of using GetAsByteArray afterwards. Or simply use GetAsByteArray(passwords) without SaveAs.
I have a problem when I want to delete a row in a CSV File, I have this code but only deletes the field that contains the line.
Example:
CSV File:
ID,Name,Lastname,Country
1,David,tod,UK
2,Juan,Perez,Germ
3,Pepe,Lopez,Col
First iteration, sending the id 1 to delete the line:
ID,Name,Lastname,Country
David,tod,UK
2,Juan,Perez,Germ
3,Pepe,Lopez,Arg
Just delete the id I want, but not the whole line
The expected result would be that like this:
ID,Name,Lastname,Country
2,Juan,Perez,Arg
3,Pepe,Lopez,Col
this is my code, What am I doing wrong? I have never used csv in C# :(
string searchid = "1";
string[] values = File.ReadAllText("C:\\registros.csv").Split(new char[] { ',' });
StringBuilder ObjStringBuilder = new StringBuilder();
for (int i = 0; i < values.Length; i++)
{
if (values[i].Contains(searchid))
continue;
ObjStringBuilder.Append(values[i] + ",");
}
ObjStringBuilder.ToString().Remove(ObjStringBuilder.Length - 1);
File.WriteAllText("\\registros.csv", ObjStringBuilder.ToString());
Another question is how can I show the CSV file in a datagridview in Windows Forms. I have this logic, don't know if this is correct, but how I can show it?
public DataTable ConvertCSVtoDataTable()
{
StreamReader sr = new StreamReader("\\registros.csv");
string[] headers = sr.ReadLine().Split(',');
DataTable dt = new DataTable();
foreach (string header in headers)
{
dt.Columns.Add(header);
}
while (!sr.EndOfStream)
{
string[] rows = Regex.Split(sr.ReadLine(), ",(?=(?:[^\"]*\"[^\"]*\")*[^\"]*$)");
DataRow dr = dt.NewRow();
for (int i = 0; i < headers.Length; i++)
{
dr[i] = rows[i];
}
dt.Rows.Add(dr);
}
return dt;
}
Thanks!
You can delete row from CSV using below link
Delete rows from CSV
and
You can convert the CSV into DataTable using the below code. If your csv file uses delimiter as ,
public DataTable ReadCSV(String FilePath, Boolean IsHeader)
{
string strConn = null;
string folderpath = null;
try
{
folderpath = FilePath.Substring(0, FilePath.LastIndexOf("\\") + 1);
string FileName = Path.GetFileName(FilePath);
if (IsHeader == true)
{
strConn = "Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + folderpath + ";" + "Extended Properties=\"text;HDR=YES\"";
}
else
{
strConn = "Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + folderpath + ";" + "Extended Properties=\"text;HDR=NO\"";
}
OleDbConnection Conn = new OleDbConnection();
Conn.ConnectionString = strConn;
Conn.Open();
string s1 = "select * from [" + FileName + "]";
OleDbDataAdapter da1 = new OleDbDataAdapter(s1, Conn);
DataSet dtall = new DataSet();
da1.Fill(dtall);
Conn.Close();
return dtall.Tables[0].Copy();
}
catch (Exception ex)
{
Exception excep = new Exception("CSV : " + ex.Message);
throw excep;
}
}
Reading and writing CSV files is not as trivial as it first seems. Cells can have embedded commas, and even new line characters. The following is one implementation of a CSV reader which can optionally be run asynchronously as a background worker. This implementation returns a standard DataTable which can easily be bound to a DataGridView:
grid.DataSource = dataTable;
The CsvReader class:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.IO;
using System.Linq;
using System.Text;
namespace CsvReaderExample
{
public class CsvReader
: BackgroundWorker
{
string[] m_lines;
public DataTable DataTable { get; private set; }
public CsvReader(string[] lines)
{
m_lines = lines;
WorkerReportsProgress = true;
WorkerSupportsCancellation = true;
}
public DataTable RunWorker()
{
return DataTable = ParseCsvLines();
}
protected override void OnDoWork(DoWorkEventArgs e)
{
base.OnDoWork(e);
e.Result = DataTable = ParseCsvLines();
}
private DataTable ParseCsvLines()
{
if (m_lines.Length == 0)
return null;
var table = new DataTable();
var columns = table.Columns;
var columnNames = GetRowValues(m_lines[0]);
foreach (var columnName in columnNames)
{
var name = columnName;
int number = 2;
while (columns.Contains(name))
name += " " + number++;
columns.Add(name);
}
var rows = table.Rows;
for (int index = 1, linesCount = m_lines.Length; index < linesCount; index++)
{
if (CancellationPending)
return null;
var line = m_lines[index];
var values = GetRowValues(line);
int valueCount = values.Count;
if (valueCount > columns.Count)
{
int columnNumber = columns.Count;
while (columns.Contains(columnNumber.ToString()))
columnNumber++;
columns.Add(columnNumber.ToString());
}
rows.Add(values.ToArray());
if (WorkerReportsProgress)
ReportProgress(100 * index / linesCount);
}
return table;
}
const char COMMA = ',',
DOUBLE_QUOTE = '"',
VERTICAL_BAR = '|';
private List<string> GetRowValues(string line)
{
var builder = new StringBuilder();
var values = new List<string>();
var inDoubleQuotes = false;
var maxIndex = line.Length - 1;
for (int index = 0; index <= maxIndex; index++)
{
char c = line[index];
if (c == DOUBLE_QUOTE)
{
if (index == 0)
{
inDoubleQuotes = true;
continue;
}
if (index < maxIndex)
{
var nextIndex = index + 1;
if (nextIndex < maxIndex)
{
if (line[nextIndex] == DOUBLE_QUOTE)
{
index++;
if (inDoubleQuotes)
builder.Append(DOUBLE_QUOTE);
continue;
}
}
}
inDoubleQuotes = !inDoubleQuotes;
continue;
}
if (c == COMMA)
{
if (inDoubleQuotes)
{
builder.Append(c);
continue;
}
values.Add(builder.ToString());
builder = new StringBuilder();
continue;
}
builder.Append(c);
}
values.Add(builder.ToString());
return values;
}
#region Sanitise cells with new line characters
public static void SanitiseCellsWithNewLineCharacters(string fileName)
{
var text = File.ReadAllText(fileName, Encoding.Default);
text = text.Replace("\r\n", "\n");
text = text.Replace("\r", "\n");
using (var writer = File.CreateText(fileName))
{
var inDoubleQuotes = false;
foreach (char c in text)
{
if (c == '\n' && inDoubleQuotes)
{
writer.Write(VERTICAL_BAR);
continue;
}
if (c == DOUBLE_QUOTE)
{
if (inDoubleQuotes)
inDoubleQuotes = false;
else
inDoubleQuotes = true;
}
writer.Write(c);
}
}
}
#endregion
}
}
You can read the DataTable synchronously as follows:
var lines = File.ReadAllLines("C:\\registros.csv");
var csvReader = new CsvReader(lines);
var dataTable = csvReader.RunWorker();
You could then remove row(s) from the DataTable with a method such as:
private static void RemoveById(DataTable dataTable, int id)
{
var column = dataTable.Columns["ID"];
if (column == null)
return;
var rows = dataTable.Rows;
for (int index = rows.Count - 1; index >= 0; index--)
{
var row = rows[index];
var value = row ["ID"];
if (value == null)
continue;
if (value.Equals(id))
{
rows.RemoveAt(index);
return;
}
}
}
Call it:
RemoveById(dataTable, 1);
The first thing that is wrong with your implementation is that you use ',' as the separator. You should either split on the new-line character '\n' or read the file line by line as follows:
var lines = new List<string>();
var file = new System.IO.StreamReader("c:\\registros.csv");
string line;
while((line = file.ReadLine()) != null)
{
lines.Add(line);
}
file.Close();
You could then look for the line that starts with the id you are looking for. When you find it, remove the line from the list.
for(int i=0; i++; i<lines.Count)
{
if (lines[i].StartsWith(searchid))
{
lines.RemoveAt(i);
break;
}
}
Next step is to write the result back to the file:
File.WriteAllLines("c:\\registros.csv", lines);
Regarding your second question, I found a similar Q/A on stackoverflow here.
First step is creating the DataTable, then you'll have to bind the table to the table control that will show the data.
SIMPLE & UNDERSTANDABLE!`
Solution For your First Problem is:
****Reading & Writing back to CSV File!****
string searchid = "1";
string[] values = File.ReadAllText(#"Complete Path Of File").Split(new char[] { '\n' });
StringBuilder ObjStringBuilder = new StringBuilder();
for (int i = 0; i < values.Length - 1; i++)
{
if (values[i].StartsWith(searchid) == false)
{
ObjStringBuilder.Append(values[i]+"\n");
}
}
File.WriteAllText(#"Complete Path Of File", ObjStringBuilder.ToString());
}
Answer to your Second Doubt:
****Populating DataGridView dynamically from CSV File!****
Comma(,) Problem SOLVED:
DataTable dtDataSource = new DataTable();
string[] fileContent = File.ReadAllLines(#"..\\Book1.csv");
if (fileContent.Count() > 0)
{
//Create data table columns dynamically
string[] columns = fileContent[0].Split(',');
for (int i = 0; i < columns.Count(); i++)
{
dtDataSource.Columns.Add(columns[i]);
}
//Add row data dynamically
for (int i = 1; i < fileContent.Count(); i++)
{
string[] rowData = fileContent[i].Split(',');
string[] realRowData = new string[columns.Count()];
StringBuilder collaboration = new StringBuilder();
int v = 0;
//this region solves the problem of a cell containing ",".
#region CommaSepProblem
for (int j = 0, K = 0; j < rowData.Count(); j++, K++)
{
//After splitting the line with commas. The cells containing commas will also be splitted.
//Fact: if a cell contains special symbol in excel that cell will be saved in .csv contained in quotes E.g A+B will be saved "A+B" or A,B will be saved as "A,B"
//Our code splits everything where comma is found. So solution is:
//Logic: After splitting if a string contains even number of DoubleQuote then its perfect cell otherwise, it is splitted in multiple cells of array.
if ((rowData[j].Count(x => x == '"') % 2 == 0))//checks if the string contains even number of DoubleQuotes
{
realRowData[K] = quotesLogic((rowData[j]));
}
else if ((rowData[j].Count(x => x == '"') % 2 != 0))//If Number of DoubleQuotes are ODD
{
int c = rowData[j].Count(x => x == '"');
v = j;
while (c % 2 != 0)//Go through all the next array cell till it makes EVEN Number of DoubleQuotes.
{
collaboration.Append(rowData[j] + ",");
j++;
c += rowData[j].Count(x => x == '"');
}
collaboration.Append(rowData[j]);
realRowData[K] = quotesLogic(collaboration.ToString());
}
else { continue; }
}
#endregion
dtDataSource.Rows.Add(realRowData);
}
if (dtDataSource != null)
{
dataGrid1.ItemsSource = dtDataSource.DefaultView;
}
}
Add This Method Too:
string quotesLogic(string collaboration)
{
StringBuilder after = new StringBuilder(collaboration);
if (after.ToString().StartsWith("\"") && after.ToString().EndsWith("\""))//removes 1st and last quotes as those are system generated
{
after.Remove(0, 1);
after.Remove(after.Length - 1, 1);
int count = after.Length - 1;
//FACT: if you try to add DoubleQuote in a cell in excel. It'll save that quote as 2 times DoubleQuote(Like "") which means first DoubleQuote is to give instruction to CPU that the next DoubleQuote is not system generated.
while (count > 0)//This loop find twice insertion of 2 DoubleQuotes and neutralise them to One DoubleQuote.
{
if (after[count] == '"' && after[count - 1] == '"')
{
after.Remove(count, 1);
}
count--;
}
}
return after.ToString();
}
I would like to read the contents of a CSV file and create a dataset.
I am trying like this:
var lines = File.ReadAllLines("test.csv").Select(a => a.Split(';'));
DataSet ds = new DataSet();
ds.load(lines);
but apparently this is not correct.
You need to add the reference Microsoft.VisualBasic.dll to use TextFieldParser Class.
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)
{
DataColumn datecolumn = new DataColumn(column);
datecolumn.AllowDBNull = true;
csvData.Columns.Add(datecolumn);
}
while (!csvReader.EndOfData)
{
string[] fieldData = csvReader.ReadFields();
//Making empty value as null
for (int i = 0; i < fieldData.Length; i++)
{
if (fieldData[i] == "")
{
fieldData[i] = null;
}
}
csvData.Rows.Add(fieldData);
}
}
}
catch (Exception ex)
{
}
return csvData;
}
}
See this article for more info : http://www.morgantechspace.com/2013/08/how-to-read-data-from-csv-file-in-c.html
You need to run a SELECT statement against the CSV file to fill the dataset:
Edit: here's some sample code from http://carllbrown.blogspot.co.uk/2007/09/populate-dataset-from-csv-delimited_18.html
string FileName = ...
OleDbConnection conn = new OleDbConnection
("Provider=Microsoft.Jet.OleDb.4.0; Data Source = " +
Path.GetDirectoryName(FileName) +
"; Extended Properties = \"Text;HDR=YES;FMT=Delimited\"");
conn.Open();
OleDbDataAdapter adapter = new OleDbDataAdapter
("SELECT * FROM " + Path.GetFileName(FileName), conn);
DataSet ds = new DataSet("Temp");
adapter.Fill(ds);
conn.Close();
You can use Library like Fast CSV Reader then
using System.IO;
using LumenWorks.Framework.IO.Csv;
void ReadCsv()
{
// open the file "data.csv" which is a CSV file with headers
using (CsvReader csv = new CsvReader(
new StreamReader("data.csv"), true))
{
myDataRepeater.DataSource = csv;
myDataRepeater.DataBind();
}
}
Comma (,) Problem Solved in This Code
Works Even If you add Commas(,) in between a cell
Reading CSV file CODE:
public MainWindow()
{
InitializeComponent();
DataTable dtDataSource = new DataTable();
string[] fileContent = File.ReadAllLines(#"..\\Book1.csv");
if (fileContent.Count() > 0)
{
//Create data table columns dynamically
string[] columns = fileContent[0].Split(',');
for (int i = 0; i < columns.Count(); i++)
{
dtDataSource.Columns.Add(columns[i]);
}
//Add row data dynamically
for (int i = 1; i < fileContent.Count(); i++)
{
string[] rowData = fileContent[i].Split(',');
string[] realRowData = new string[columns.Count()];
StringBuilder collaboration = new StringBuilder();
int v = 0;
//this region solves the problem of a cell containing ",".
#region CommaSepProblem
for (int j = 0, K = 0; j < rowData.Count(); j++, K++)
{
if ((rowData[j].Count(x => x == '"') % 2 == 0))//checks if the string contains even number of DoubleQuotes
{
realRowData[K] = quotesLogic((rowData[j]));
}
else if ((rowData[j].Count(x => x == '"') % 2 != 0))//If Number of DoubleQuotes are ODD
{
int c = rowData[j].Count(x => x == '"');
v = j;
while (c % 2 != 0)//Go through all the next array cell till it makes EVEN Number of DoubleQuotes.
{
collaboration.Append(rowData[j] + ",");
j++;
c += rowData[j].Count(x => x == '"');
}
collaboration.Append(rowData[j]);
realRowData[K] = quotesLogic(collaboration.ToString());
}
else { continue; }
}
#endregion
dtDataSource.Rows.Add(realRowData);
}
if (dtDataSource != null)
{
//dataGridView1 = new DataGridView();
dataGrid1.ItemsSource = dtDataSource.DefaultView;
}
}
}
Method Need to be added:
string quotesLogic(string collaboration)
{
StringBuilder after = new StringBuilder(collaboration);
if (after.ToString().StartsWith("\"") && after.ToString().EndsWith("\""))//removes 1st and last quotes as those are system generated
{
after.Remove(0, 1);
after.Remove(after.Length - 1, 1);
int count = after.Length - 1;
//FACT: if you try to add DoubleQuote in a cell in excel. It'll save that quote as 2 times DoubleQuote(Like "") which means first DoubleQuote is to give instruction to CPU that the next DoubleQuote is not system generated.
while (count > 0)//This loop find twice insertion of 2 DoubleQuotes and neutralise them to One DoubleQuote.
{
if (after[count] == '"' && after[count - 1] == '"')
{
after.Remove(count, 1);
}
count--;
}
}
return after.ToString();
}
If you just want to quickly create a DataTable filled with sample data from a CSV file (or pasted directly from Excel) to play around or prototype, then you can use my fork of Shan Carter's Mr. Data Converter -- I recently added the ability to output comma- and tab-delimited data to a C# DataTable.
http://thdoan.github.io/mr-data-converter/
I have written five methods below that will turn a Csv file into a DataTable.
They have been designed to take into account optional quote marks (e.g. " symbols) and to be as versatile as possible without using other libraries:
public static DataTable GetDataTabletFromCSVFile(string filePath, bool isHeadings)
{
DataTable MethodResult = null;
try
{
using (TextFieldParser TextFieldParser = new TextFieldParser(filePath))
{
if (isHeadings)
{
MethodResult = GetDataTableFromTextFieldParser(TextFieldParser);
}
else
{
MethodResult = GetDataTableFromTextFieldParserNoHeadings(TextFieldParser);
}
}
}
catch (Exception ex)
{
ex.HandleException();
}
return MethodResult;
}
public static DataTable GetDataTableFromCsvString(string csvBody, bool isHeadings)
{
DataTable MethodResult = null;
try
{
MemoryStream MemoryStream = new MemoryStream();
StreamWriter StreamWriter = new StreamWriter(MemoryStream);
StreamWriter.Write(csvBody);
StreamWriter.Flush();
MemoryStream.Position = 0;
using (TextFieldParser TextFieldParser = new TextFieldParser(MemoryStream))
{
if (isHeadings)
{
MethodResult = GetDataTableFromTextFieldParser(TextFieldParser);
}
else
{
MethodResult = GetDataTableFromTextFieldParserNoHeadings(TextFieldParser);
}
}
}
catch (Exception ex)
{
ex.HandleException();
}
return MethodResult;
}
public static DataTable GetDataTableFromRemoteCsv(string url, bool isHeadings)
{
DataTable MethodResult = null;
try
{
HttpWebRequest httpWebRequest = (HttpWebRequest)WebRequest.Create(url);
HttpWebResponse httpWebResponse = (HttpWebResponse)httpWebRequest.GetResponse();
StreamReader StreamReader = new StreamReader(httpWebResponse.GetResponseStream());
using (TextFieldParser TextFieldParser = new TextFieldParser(StreamReader))
{
if (isHeadings)
{
MethodResult = GetDataTableFromTextFieldParser(TextFieldParser);
}
else
{
MethodResult = GetDataTableFromTextFieldParserNoHeadings(TextFieldParser);
}
}
}
catch (Exception ex)
{
ex.HandleException();
}
return MethodResult;
}
private static DataTable GetDataTableFromTextFieldParser(TextFieldParser textFieldParser)
{
DataTable MethodResult = null;
try
{
textFieldParser.SetDelimiters(new string[] { "," });
textFieldParser.HasFieldsEnclosedInQuotes = true;
string[] ColumnFields = textFieldParser.ReadFields();
DataTable dt = new DataTable();
foreach (string ColumnField in ColumnFields)
{
DataColumn DataColumn = new DataColumn(ColumnField);
DataColumn.AllowDBNull = true;
dt.Columns.Add(DataColumn);
}
while (!textFieldParser.EndOfData)
{
string[] Fields = textFieldParser.ReadFields();
for (int i = 0; i < Fields.Length; i++)
{
if (Fields[i] == "")
{
Fields[i] = null;
}
}
dt.Rows.Add(Fields);
}
MethodResult = dt;
}
catch (Exception ex)
{
ex.HandleException();
}
return MethodResult;
}
private static DataTable GetDataTableFromTextFieldParserNoHeadings(TextFieldParser textFieldParser)
{
DataTable MethodResult = null;
try
{
textFieldParser.SetDelimiters(new string[] { "," });
textFieldParser.HasFieldsEnclosedInQuotes = true;
bool FirstPass = true;
DataTable dt = new DataTable();
while (!textFieldParser.EndOfData)
{
string[] Fields = textFieldParser.ReadFields();
if(FirstPass)
{
for (int i = 0; i < Fields.Length; i++)
{
DataColumn DataColumn = new DataColumn("Column " + i);
DataColumn.AllowDBNull = true;
dt.Columns.Add(DataColumn);
}
FirstPass = false;
}
for (int i = 0; i < Fields.Length; i++)
{
if (Fields[i] == "")
{
Fields[i] = null;
}
}
dt.Rows.Add(Fields);
}
MethodResult = dt;
}
catch (Exception ex)
{
ex.HandleException();
}
return MethodResult;
}
If, like me, you're saving from reporting services then you should use it like this:
Warning[] warnings;
string[] streamids;
string mimeType;
string encoding;
string filenameExtension;
byte[] bytes = rvMain.ServerReport.Render("csv", null, out mimeType, out encoding, out filenameExtension, out streamids, out warnings);
string CsvBody = System.Text.Encoding.UTF8.GetString(bytes);
DataTable dt = GetDataTableFromCsvString(CsvBody,true);
Otherwise, all you need do is:
bool IsHeadings = true; //Does the data include a heading row?
DataTable dt = GetDataTableFromCsvString(CsvBody, IsHeadings);
Or to use directly from a csv file
bool IsHeadings = true; //Does the data include a heading row?
DataTable dt = GetDataTabletFromCsvFile(FilePath, IsHeadings)
Or to use a csv file that is stored remotely
bool IsHeadings = true; //Does the data include a heading row?
DataTable dt = GetDataTabletFromRemoteCsv(Url, IsHeadings)
A Dataset is a collection of DataTables, so create one like so:
DataSet ds = new DataSet();
ds.Tables.Add(dt);
I'm working on a application which will export my DataGridView called scannerDataGridView to a csv file.
Found some example code to do this, but can't get it working. Btw my datagrid isn't databound to a source.
When i try to use the Streamwriter to only write the column headers everything goes well, but when i try to export the whole datagrid including data i get an exeption trhown.
System.NullReferenceException: Object reference not set to an instance
of an object. at Scanmonitor.Form1.button1_Click(Object sender,
EventArgs e)
Here is my Code, error is given on the following line:
dataFromGrid = dataFromGrid + ',' + dataRowObject.Cells[i].Value.ToString();
//csvFileWriter = StreamWriter
//scannerDataGridView = DataGridView
private void button1_Click(object sender, EventArgs e)
{
string CsvFpath = #"C:\scanner\CSV-EXPORT.csv";
try
{
System.IO.StreamWriter csvFileWriter = new StreamWriter(CsvFpath, false);
string columnHeaderText = "";
int countColumn = scannerDataGridView.ColumnCount - 1;
if (countColumn >= 0)
{
columnHeaderText = scannerDataGridView.Columns[0].HeaderText;
}
for (int i = 1; i <= countColumn; i++)
{
columnHeaderText = columnHeaderText + ',' + scannerDataGridView.Columns[i].HeaderText;
}
csvFileWriter.WriteLine(columnHeaderText);
foreach (DataGridViewRow dataRowObject in scannerDataGridView.Rows)
{
if (!dataRowObject.IsNewRow)
{
string dataFromGrid = "";
dataFromGrid = dataRowObject.Cells[0].Value.ToString();
for (int i = 1; i <= countColumn; i++)
{
dataFromGrid = dataFromGrid + ',' + dataRowObject.Cells[i].Value.ToString();
csvFileWriter.WriteLine(dataFromGrid);
}
}
}
csvFileWriter.Flush();
csvFileWriter.Close();
}
catch (Exception exceptionObject)
{
MessageBox.Show(exceptionObject.ToString());
}
LINQ FTW!
var sb = new StringBuilder();
var headers = dataGridView1.Columns.Cast<DataGridViewColumn>();
sb.AppendLine(string.Join(",", headers.Select(column => "\"" + column.HeaderText + "\"").ToArray()));
foreach (DataGridViewRow row in dataGridView1.Rows)
{
var cells = row.Cells.Cast<DataGridViewCell>();
sb.AppendLine(string.Join(",", cells.Select(cell => "\"" + cell.Value + "\"").ToArray()));
}
And indeed, c.Value.ToString() will throw on null value, while c.Value will correctly convert to an empty string.
A little known feature of the DataGridView is the ability to programmatically select some or all of the DataGridCells, and send them to a DataObject using the method DataGridView.GetClipboardContent(). Whats the advantage of this then?
A DataObject doesn't just store an object, but rather the representation of that object in various different formats. This is how the Clipboard is able to work its magic; it has various formats stored and different controls/classes can specify which format they wish to accept. In this case, the DataGridView will store the selected cells in the DataObject as a tab-delimited text format, a CSV format, or as HTML (*).
The contents of the DataObject can be retrieved by calling the DataObject.GetData() or DataObject.GetText() methods and specifying a predefined data format enum. In this case, we want the format to be TextDataFormat.CommaSeparatedValue for CSV, then we can just write that result to a file using System.IO.File class.
(*) Actually, what it returns is not, strictly speaking, HTML. This format will also contain a data header that you were not expecting. While the header does contain the starting position of the HTML, I just discard anything above the HTML tag like myString.Substring(IndexOf("<HTML>"));.
Observe the following code:
void SaveDataGridViewToCSV(string filename)
{
// Choose whether to write header. Use EnableWithoutHeaderText instead to omit header.
dataGridView1.ClipboardCopyMode = DataGridViewClipboardCopyMode.EnableAlwaysIncludeHeaderText;
// Select all the cells
dataGridView1.SelectAll();
// Copy selected cells to DataObject
DataObject dataObject = dataGridView1.GetClipboardContent();
// Get the text of the DataObject, and serialize it to a file
File.WriteAllText(filename, dataObject.GetText(TextDataFormat.CommaSeparatedValue));
}
Now, isn't that better? Why re-invent the wheel?
Hope this helps...
Please check this code.its working fine
try
{
//Build the CSV file data as a Comma separated string.
string csv = string.Empty;
//Add the Header row for CSV file.
foreach (DataGridViewColumn column in dataGridView1.Columns)
{
csv += column.HeaderText + ',';
}
//Add new line.
csv += "\r\n";
//Adding the Rows
foreach (DataGridViewRow row in dataGridView1.Rows)
{
foreach (DataGridViewCell cell in row.Cells)
{
if (cell.Value != null)
{
//Add the Data rows.
csv += cell.Value.ToString().TrimEnd(',').Replace(",", ";") + ',';
}
// break;
}
//Add new line.
csv += "\r\n";
}
//Exporting to CSV.
string folderPath = "C:\\CSV\\";
if (!Directory.Exists(folderPath))
{
Directory.CreateDirectory(folderPath);
}
File.WriteAllText(folderPath + "Invoice.csv", csv);
MessageBox.Show("");
}
catch
{
MessageBox.Show("");
}
Found the problem, the coding was fine but i had an empty cell that gave the problem.
Your code was almost there... But I made the following corrections and it works great. Thanks for the post.
Error:
string[] output = new string[dgvLista_Apl_Geral.RowCount + 1];
Correction:
string[] output = new string[DGV.RowCount + 1];
Error:
System.IO.File.WriteAllLines(filename, output, System.Text.Encoding.UTF8);
Correction:
System.IO.File.WriteAllLines(sfd.FileName, output, System.Text.Encoding.UTF8);
The line "csvFileWriter.WriteLine(dataFromGrid);" should be moved down one line below the closing bracket, else you'll get a lot of repeating results:
for (int i = 1; i <= countColumn; i++)
{
dataFromGrid = dataFromGrid + ',' + dataRowObject.Cells[i].Value.ToString();
}
csvFileWriter.WriteLine(dataFromGrid);
I think this is the correct for your SaveToCSV function : ( otherwise Null ...)
for (int i = 0; i < columnCount; i++)
Not :
for (int i = 1; (i - 1) < DGV.RowCount; i++)
This is what I been using in my projects:
void export_csv(string file, DataGridView grid)
{
using (StreamWriter csv = new StreamWriter(file, false))
{
int totalcolms = grid.ColumnCount;
foreach (DataGridViewColumn colm in grid.Columns) csv.Write(colm.HeaderText + ',');
csv.Write('\n');
string data = "";
foreach (DataGridViewRow row in grid.Rows)
{
if (row.IsNewRow) continue;
data = "";
for (int i = 0; i < totalcolms; i++)
{
data += (row.Cells[i].Value ?? "").ToString() + ',';
}
if (data != string.Empty) csv.WriteLine(data);
}
}
}
Could somebody please tell me why the following code is not working. The data is saved into the csv file, however the data is not separated. It all exists within the first cell of each row.
StringBuilder sb = new StringBuilder();
foreach (DataColumn col in dt.Columns)
{
sb.Append(col.ColumnName + ',');
}
sb.Remove(sb.Length - 1, 1);
sb.Append(Environment.NewLine);
foreach (DataRow row in dt.Rows)
{
for (int i = 0; i < dt.Columns.Count; i++)
{
sb.Append(row[i].ToString() + ",");
}
sb.Append(Environment.NewLine);
}
File.WriteAllText("test.csv", sb.ToString());
Thanks.
The following shorter version opens fine in Excel, maybe your issue was the trailing comma
.net = 3.5
StringBuilder sb = new StringBuilder();
string[] columnNames = dt.Columns.Cast<DataColumn>().
Select(column => column.ColumnName).
ToArray();
sb.AppendLine(string.Join(",", columnNames));
foreach (DataRow row in dt.Rows)
{
string[] fields = row.ItemArray.Select(field => field.ToString()).
ToArray();
sb.AppendLine(string.Join(",", fields));
}
File.WriteAllText("test.csv", sb.ToString());
.net >= 4.0
And as Tim pointed out, if you are on .net>=4, you can make it even shorter:
StringBuilder sb = new StringBuilder();
IEnumerable<string> columnNames = dt.Columns.Cast<DataColumn>().
Select(column => column.ColumnName);
sb.AppendLine(string.Join(",", columnNames));
foreach (DataRow row in dt.Rows)
{
IEnumerable<string> fields = row.ItemArray.Select(field => field.ToString());
sb.AppendLine(string.Join(",", fields));
}
File.WriteAllText("test.csv", sb.ToString());
As suggested by Christian, if you want to handle special characters escaping in fields, replace the loop block by:
foreach (DataRow row in dt.Rows)
{
IEnumerable<string> fields = row.ItemArray.Select(field =>
string.Concat("\"", field.ToString().Replace("\"", "\"\""), "\""));
sb.AppendLine(string.Join(",", fields));
}
And last suggestion, you could write the csv content line by line instead of as a whole document, to avoid having a big document in memory.
I wrapped this up into an extension class, which allows you to call:
myDataTable.WriteToCsvFile("C:\\MyDataTable.csv");
on any DataTable.
public static class DataTableExtensions
{
public static void WriteToCsvFile(this DataTable dataTable, string filePath)
{
StringBuilder fileContent = new StringBuilder();
foreach (var col in dataTable.Columns)
{
fileContent.Append(col.ToString() + ",");
}
fileContent.Replace(",", System.Environment.NewLine, fileContent.Length - 1, 1);
foreach (DataRow dr in dataTable.Rows)
{
foreach (var column in dr.ItemArray)
{
fileContent.Append("\"" + column.ToString() + "\",");
}
fileContent.Replace(",", System.Environment.NewLine, fileContent.Length - 1, 1);
}
System.IO.File.WriteAllText(filePath, fileContent.ToString());
}
}
A new extension function based on Paul Grimshaw's answer. I cleaned it up and added the ability to handle unexpected data. (Empty Data, Embedded Quotes, and comma's in the headings...)
It also returns a string which is more flexible. It returns Null if the table object does not contain any structure.
public static string ToCsv(this DataTable dataTable) {
StringBuilder sbData = new StringBuilder();
// Only return Null if there is no structure.
if (dataTable.Columns.Count == 0)
return null;
foreach (var col in dataTable.Columns) {
if (col == null)
sbData.Append(",");
else
sbData.Append("\"" + col.ToString().Replace("\"", "\"\"") + "\",");
}
sbData.Replace(",", System.Environment.NewLine, sbData.Length - 1, 1);
foreach (DataRow dr in dataTable.Rows) {
foreach (var column in dr.ItemArray) {
if (column == null)
sbData.Append(",");
else
sbData.Append("\"" + column.ToString().Replace("\"", "\"\"") + "\",");
}
sbData.Replace(",", System.Environment.NewLine, sbData.Length - 1, 1);
}
return sbData.ToString();
}
You call it as follows:
var csvData = dataTableOject.ToCsv();
If your calling code is referencing the System.Windows.Forms assembly, you may consider a radically different approach.
My strategy is to use the functions already provided by the framework to accomplish this in very few lines of code and without having to loop through columns and rows. What the code below does is programmatically create a DataGridView on the fly and set the DataGridView.DataSource to the DataTable. Next, I programmatically select all the cells (including the header) in the DataGridView and call DataGridView.GetClipboardContent(), placing the results into the Windows Clipboard. Then, I 'paste' the contents of the clipboard into a call to File.WriteAllText(), making sure to specify the formatting of the 'paste' as TextDataFormat.CommaSeparatedValue.
Here is the code:
public static void DataTableToCSV(DataTable Table, string Filename)
{
using(DataGridView dataGrid = new DataGridView())
{
// Save the current state of the clipboard so we can restore it after we are done
IDataObject objectSave = Clipboard.GetDataObject();
// Set the DataSource
dataGrid.DataSource = Table;
// Choose whether to write header. Use EnableWithoutHeaderText instead to omit header.
dataGrid.ClipboardCopyMode = DataGridViewClipboardCopyMode.EnableAlwaysIncludeHeaderText;
// Select all the cells
dataGrid.SelectAll();
// Copy (set clipboard)
Clipboard.SetDataObject(dataGrid.GetClipboardContent());
// Paste (get the clipboard and serialize it to a file)
File.WriteAllText(Filename,Clipboard.GetText(TextDataFormat.CommaSeparatedValue));
// Restore the current state of the clipboard so the effect is seamless
if(objectSave != null) // If we try to set the Clipboard to an object that is null, it will throw...
{
Clipboard.SetDataObject(objectSave);
}
}
}
Notice I also make sure to preserve the contents of the clipboard before I begin, and restore it once I'm done, so the user does not get a bunch of unexpected garbage next time the user tries to paste. The main caveats to this approach is 1) Your class has to reference System.Windows.Forms, which may not be the case in a data abstraction layer, 2) Your assembly will have to be targeted for .NET 4.5 framework, as DataGridView does not exist in 4.0, and 3) The method will fail if the clipboard is being used by another process.
Anyways, this approach may not be right for your situation, but it is interesting none the less, and can be another tool in your toolbox.
I did this recently but included double quotes around my values.
For example, change these two lines:
sb.Append("\"" + col.ColumnName + "\",");
...
sb.Append("\"" + row[i].ToString() + "\",");
Try changing sb.Append(Environment.NewLine); to sb.AppendLine();.
StringBuilder sb = new StringBuilder();
foreach (DataColumn col in dt.Columns)
{
sb.Append(col.ColumnName + ',');
}
sb.Remove(sb.Length - 1, 1);
sb.AppendLine();
foreach (DataRow row in dt.Rows)
{
for (int i = 0; i < dt.Columns.Count; i++)
{
sb.Append(row[i].ToString() + ",");
}
sb.AppendLine();
}
File.WriteAllText("test.csv", sb.ToString());
4 lines of code:
public static string ToCSV(DataTable tbl)
{
StringBuilder strb = new StringBuilder();
//column headers
strb.AppendLine(string.Join(",", tbl.Columns.Cast<DataColumn>()
.Select(s => "\"" + s.ColumnName + "\"")));
//rows
tbl.AsEnumerable().Select(s => strb.AppendLine(
string.Join(",", s.ItemArray.Select(
i => "\"" + i.ToString() + "\"")))).ToList();
return strb.ToString();
}
Note that the ToList() at the end is important; I need something to force an expression evaluation. If I was code golfing, I could use Min() instead.
Also note that the result will have a newline at the end because of the last call to AppendLine(). You may not want this. You can simply call TrimEnd() to remove it.
Try to put ; instead of ,
Hope it helps
The error is the list separator.
Instead of writing sb.Append(something... + ',') you should put something like sb.Append(something... + System.Globalization.CultureInfo.CurrentCulture.TextInfo.ListSeparator);
You must put the list separator character configured in your operating system (like in the example above), or the list separator in the client machine where the file is going to be watched. Another option would be to configure it in the app.config or web.config as a parammeter of your application.
To write to a file, I think the following method is the most efficient and straightforward: (You can add quotes if you want)
public static void WriteCsv(DataTable dt, string path)
{
using (var writer = new StreamWriter(path)) {
writer.WriteLine(string.Join(",", dt.Columns.Cast<DataColumn>().Select(dc => dc.ColumnName)));
foreach (DataRow row in dt.Rows) {
writer.WriteLine(string.Join(",", row.ItemArray));
}
}
}
Read this and this?
A better implementation would be
var result = new StringBuilder();
for (int i = 0; i < table.Columns.Count; i++)
{
result.Append(table.Columns[i].ColumnName);
result.Append(i == table.Columns.Count - 1 ? "\n" : ",");
}
foreach (DataRow row in table.Rows)
{
for (int i = 0; i < table.Columns.Count; i++)
{
result.Append(row[i].ToString());
result.Append(i == table.Columns.Count - 1 ? "\n" : ",");
}
}
File.WriteAllText("test.csv", result.ToString());
To mimic Excel CSV:
public static string Convert(DataTable dt)
{
StringBuilder sb = new StringBuilder();
IEnumerable<string> columnNames = dt.Columns.Cast<DataColumn>().
Select(column => column.ColumnName);
sb.AppendLine(string.Join(",", columnNames));
foreach (DataRow row in dt.Rows)
{
IEnumerable<string> fields = row.ItemArray.Select(field =>
{
string s = field.ToString().Replace("\"", "\"\"");
if(s.Contains(','))
s = string.Concat("\"", s, "\"");
return s;
});
sb.AppendLine(string.Join(",", fields));
}
return sb.ToString().Trim();
}
Here is an enhancement to vc-74's post that handles commas the same way Excel does. Excel puts quotes around data if the data has a comma but doesn't quote if the data doesn't have a comma.
public static string ToCsv(this DataTable inDataTable, bool inIncludeHeaders = true)
{
var builder = new StringBuilder();
var columnNames = inDataTable.Columns.Cast<DataColumn>().Select(column => column.ColumnName);
if (inIncludeHeaders)
builder.AppendLine(string.Join(",", columnNames));
foreach (DataRow row in inDataTable.Rows)
{
var fields = row.ItemArray.Select(field => field.ToString().WrapInQuotesIfContains(","));
builder.AppendLine(string.Join(",", fields));
}
return builder.ToString();
}
public static string WrapInQuotesIfContains(this string inString, string inSearchString)
{
if (inString.Contains(inSearchString))
return "\"" + inString+ "\"";
return inString;
}
Here is my solution, based on previous answers by Paul Grimshaw and Anthony VO.
I've submitted the code in a C# project on Github.
My main contribution is to eliminate explicitly creating and manipulating a StringBuilder and instead working only with IEnumerable. This avoids the allocation of a big buffer in memory.
public static class Util
{
public static string EscapeQuotes(this string self) {
return self?.Replace("\"", "\"\"") ?? "";
}
public static string Surround(this string self, string before, string after) {
return $"{before}{self}{after}";
}
public static string Quoted(this string self, string quotes = "\"") {
return self.Surround(quotes, quotes);
}
public static string QuotedCSVFieldIfNecessary(this string self)
{
return (self == null) ? "" : (self.Contains('"') || self.Contains('\r') || self.Contains('\n') || self.Contains(',')) ? self.Quoted() : self;
}
public static string ToCsvField(this string self) {
return self.EscapeQuotes().QuotedCSVFieldIfNecessary();
}
public static string ToCsvRow(this IEnumerable<string> self){
return string.Join(",", self.Select(ToCsvField));
}
public static IEnumerable<string> ToCsvRows(this DataTable self) {
yield return self.Columns.OfType<object>().Select(c => c.ToString()).ToCsvRow();
foreach (var dr in self.Rows.OfType<DataRow>())
yield return dr.ItemArray.Select(item => item.ToString()).ToCsvRow();
}
public static void ToCsvFile(this DataTable self, string path) {
File.WriteAllLines(path, self.ToCsvRows());
}
}
This approach combines nicely with converting IEnumerable to DataTable as asked here.
StringBuilder sb = new StringBuilder();
SaveFileDialog fileSave = new SaveFileDialog();
IEnumerable<string> columnNames = tbCifSil.Columns.Cast<DataColumn>().
Select(column => column.ColumnName);
sb.AppendLine(string.Join(",", columnNames));
foreach (DataRow row in tbCifSil.Rows)
{
IEnumerable<string> fields = row.ItemArray.Select(field =>string.Concat("\"", field.ToString().Replace("\"", "\"\""), "\""));
sb.AppendLine(string.Join(",", fields));
}
fileSave.ShowDialog();
File.WriteAllText(fileSave.FileName, sb.ToString());
public void ExpoetToCSV(DataTable dtDataTable, string strFilePath)
{
StreamWriter sw = new StreamWriter(strFilePath, false);
//headers
for (int i = 0; i < dtDataTable.Columns.Count; i++)
{
sw.Write(dtDataTable.Columns[i].ToString().Trim());
if (i < dtDataTable.Columns.Count - 1)
{
sw.Write(",");
}
}
sw.Write(sw.NewLine);
foreach (DataRow dr in dtDataTable.Rows)
{
for (int i = 0; i < dtDataTable.Columns.Count; i++)
{
if (!Convert.IsDBNull(dr[i]))
{
string value = dr[i].ToString().Trim();
if (value.Contains(','))
{
value = String.Format("\"{0}\"", value);
sw.Write(value);
}
else
{
sw.Write(dr[i].ToString().Trim());
}
}
if (i < dtDataTable.Columns.Count - 1)
{
sw.Write(",");
}
}
sw.Write(sw.NewLine);
}
sw.Close();
}
Possibly, most easy way will be to use:
https://github.com/ukushu/DataExporter
especially in case of your data of datatable containing /r/n characters or separator symbol inside of your dataTable cells. Almost all of other answers will not work with such cells.
only you need is to write the following code:
Csv csv = new Csv("\t");//Needed delimiter
var columnNames = dt.Columns.Cast<DataColumn>().
Select(column => column.ColumnName).ToArray();
csv.AddRow(columnNames);
foreach (DataRow row in dt.Rows)
{
var fields = row.ItemArray.Select(field => field.ToString()).ToArray;
csv.AddRow(fields);
}
csv.Save();
Most existing answers can easily cause OutOfMemoryException, so I decided to write my own answer.
DON' T DO THIS:
using a DataSet + StringBuilder causes the data to occupy the memory 3x at once:
Load All Data into DataSet
Copy all data into StringBuilder
Copy the data to string using StringBuilder.ToString();
Instead you should write each row to a FileStream separately. There is no need to create the whole CSV in memory.
Even better, use a DataReader instead DataSet. That way you can read from database billions of records one by one a write the to a file one by one.
If you don't mind using an external library for CSV, I can recommend the most popular CsvHelper, which has no dependencies.
using (var writer = new FileWriter("test.csv"))
using (var csv = new CsvWriter(writer, CultureInfo.InvariantCulture))
{
foreach (DataColumn dc in dt.Columns)
{
csv.WriteField(dc.ColumnName);
}
csv.NextRecord();
foreach (DataRow dr in dt.Rows)
{
foreach (DataColumn dc in dt.Columns)
{
csv.WriteField(dr[dc]);
}
csv.NextRecord();
}
writer.ToString().Dump();
}
In case anyone else stumbles on this, I was using File.ReadAllText to get CSV data and then I modified it and wrote it back with File.WriteAllText. The \r\n CRLFs were fine but the \t tabs were ignored when Excel opened it. (All solutions in this thread so far use a comma delimiter but that doesn't matter.) Notepad showed the same format in the resulting file as in the source. A Diff even showed the files as identical. But I got a clue when I opened the file in Visual Studio with a binary editor. The source file was Unicode but the target was ASCII. To fix, I modified both ReadAllText and WriteAllText with third argument set as System.Text.Encoding.Unicode, and from there Excel was able to open the updated file.