I am trying to write into a csv file row by row using C# language. Here is my function
string first = reader[0].ToString();
string second=image.ToString();
string csv = string.Format("{0},{1}\n", first, second);
File.WriteAllText(filePath, csv);
The whole function runs inside a loop, and every row should be written to the csv file. In my case, next row overwrites the existing row and in the end, I am getting an only single record in the csv file which is the last one. How can I write all the rows in the csv file?
UPDATE
Back in my naïve days, I suggested doing this manually (it was a simple solution to a simple question), however due to this becoming more and more popular, I'd recommend using the library CsvHelper that does all the safety checks, etc.
CSV is way more complicated than what the question/answer suggests.
Original Answer
As you already have a loop, consider doing it like this:
//before your loop
var csv = new StringBuilder();
//in your loop
var first = reader[0].ToString();
var second = image.ToString();
//Suggestion made by KyleMit
var newLine = string.Format("{0},{1}", first, second);
csv.AppendLine(newLine);
//after your loop
File.WriteAllText(filePath, csv.ToString());
Or something to this effect.
My reasoning is: you won't be need to write to the file for every item, you will only be opening the stream once and then writing to it.
You can replace
File.WriteAllText(filePath, csv.ToString());
with
File.AppendAllText(filePath, csv.ToString());
if you want to keep previous versions of csv in the same file
C# 6
If you are using c# 6.0 then you can do the following
var newLine = $"{first},{second}"
EDIT
Here is a link to a question that explains what Environment.NewLine does.
I would highly recommend you to go the more tedious route. Especially if your file size is large.
using(var w = new StreamWriter(path))
{
for( /* your loop */)
{
var first = yourFnToGetFirst();
var second = yourFnToGetSecond();
var line = string.Format("{0},{1}", first, second);
w.WriteLine(line);
w.Flush();
}
}
File.AppendAllText() opens a new file, writes the content and then closes the file. Opening files is a much resource-heavy operation, than writing data into open stream. Opening\closing a file inside a loop will cause performance drop.
The approach suggested by Johan solves that problem by storing all the output in memory and then writing it once. However (in case of big files) you program will consume a large amount of RAM and even crash with OutOfMemoryException
Another advantage of my solution is that you can implement pausing\resuming by saving current position in input data.
upd. Placed using in the right place
Writing csv files by hand can be difficult because your data might contain commas and newlines. I suggest you use an existing library instead.
This question mentions a few options.
Are there any CSV readers/writer libraries in C#?
I use a two parse solution as it's very easy to maintain
// Prepare the values
var allLines = (from trade in proposedTrades
select new object[]
{
trade.TradeType.ToString(),
trade.AccountReference,
trade.SecurityCodeType.ToString(),
trade.SecurityCode,
trade.ClientReference,
trade.TradeCurrency,
trade.AmountDenomination.ToString(),
trade.Amount,
trade.Units,
trade.Percentage,
trade.SettlementCurrency,
trade.FOP,
trade.ClientSettlementAccount,
string.Format("\"{0}\"", trade.Notes),
}).ToList();
// Build the file content
var csv = new StringBuilder();
allLines.ForEach(line =>
{
csv.AppendLine(string.Join(",", line));
});
File.WriteAllText(filePath, csv.ToString());
Instead of calling every time AppendAllText() you could think about opening the file once and then write the whole content once:
var file = #"C:\myOutput.csv";
using (var stream = File.CreateText(file))
{
for (int i = 0; i < reader.Count(); i++)
{
string first = reader[i].ToString();
string second = image.ToString();
string csvRow = string.Format("{0},{1}", first, second);
stream.WriteLine(csvRow);
}
}
You can use AppendAllText instead:
File.AppendAllText(filePath, csv);
As the documentation of WriteAllText says:
If the target file already exists, it is overwritten
Also, note that your current code is not using proper new lines, for example in Notepad you'll see it all as one long line. Change the code to this to have proper new lines:
string csv = string.Format("{0},{1}{2}", first, image, Environment.NewLine);
Instead of reinventing the wheel a library could be used. CsvHelper is great for creating and reading csv files. It's read and write operations are stream based and therefore also support operations with a big amount of data.
You can write your csv like the following.
using(var textWriter = new StreamWriter(#"C:\mypath\myfile.csv"))
{
var writer = new CsvWriter(textWriter, CultureInfo.InvariantCulture);
writer.Configuration.Delimiter = ",";
foreach (var item in list)
{
writer.WriteField( "a" );
writer.WriteField( 2 );
writer.WriteField( true );
writer.NextRecord();
}
}
As the library is using reflection it will take any type and parse it directly.
public class CsvRow
{
public string Column1 { get; set; }
public bool Column2 { get; set; }
public CsvRow(string column1, bool column2)
{
Column1 = column1;
Column2 = column2;
}
}
IEnumerable<CsvRow> rows = new [] {
new CsvRow("value1", true),
new CsvRow("value2", false)
};
using(var textWriter = new StreamWriter(#"C:\mypath\myfile.csv")
{
var writer = new CsvWriter(textWriter, CultureInfo.InvariantCulture);
writer.Configuration.Delimiter = ",";
writer.WriteRecords(rows);
}
value1,true
value2,false
If you want to read more about the librarys configurations and possibilities you can do so here.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using System.Configuration;
using System.Data.SqlClient;
public partial class CS : System.Web.UI.Page
{
protected void ExportCSV(object sender, EventArgs e)
{
string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
using (SqlConnection con = new SqlConnection(constr))
{
using (SqlCommand cmd = new SqlCommand("SELECT * FROM Customers"))
{
using (SqlDataAdapter sda = new SqlDataAdapter())
{
cmd.Connection = con;
sda.SelectCommand = cmd;
using (DataTable dt = new DataTable())
{
sda.Fill(dt);
//Build the CSV file data as a Comma separated string.
string csv = string.Empty;
foreach (DataColumn column in dt.Columns)
{
//Add the Header row for CSV file.
csv += column.ColumnName + ',';
}
//Add new line.
csv += "\r\n";
foreach (DataRow row in dt.Rows)
{
foreach (DataColumn column in dt.Columns)
{
//Add the Data rows.
csv += row[column.ColumnName].ToString().Replace(",", ";") + ',';
}
//Add new line.
csv += "\r\n";
}
//Download the CSV file.
Response.Clear();
Response.Buffer = true;
Response.AddHeader("content-disposition", "attachment;filename=SqlExport.csv");
Response.Charset = "";
Response.ContentType = "application/text";
Response.Output.Write(csv);
Response.Flush();
Response.End();
}
}
}
}
}
}
Handling Commas
For handling commas inside of values when using string.Format(...), the following has worked for me:
var newLine = string.Format("\"{0}\",\"{1}\",\"{2}\"",
first,
second,
third
);
csv.AppendLine(newLine);
So to combine it with Johan's answer, it'd look like this:
//before your loop
var csv = new StringBuilder();
//in your loop
var first = reader[0].ToString();
var second = image.ToString();
//Suggestion made by KyleMit
var newLine = string.Format("\"{0}\",\"{1}\"", first, second);
csv.AppendLine(newLine);
//after your loop
File.WriteAllText(filePath, csv.ToString());
Returning CSV File
If you simply wanted to return the file instead of writing it to a location, this is an example of how I accomplished it:
From a Stored Procedure
public FileContentResults DownloadCSV()
{
// I have a stored procedure that queries the information I need
SqlConnection thisConnection = new SqlConnection("Data Source=sv12sql;User ID=UI_Readonly;Password=SuperSecure;Initial Catalog=DB_Name;Integrated Security=false");
SqlCommand queryCommand = new SqlCommand("spc_GetInfoINeed", thisConnection);
queryCommand.CommandType = CommandType.StoredProcedure;
StringBuilder sbRtn = new StringBuilder();
// If you want headers for your file
var header = string.Format("\"{0}\",\"{1}\",\"{2}\"",
"Name",
"Address",
"Phone Number"
);
sbRtn.AppendLine(header);
// Open Database Connection
thisConnection.Open();
using (SqlDataReader rdr = queryCommand.ExecuteReader())
{
while (rdr.Read())
{
// rdr["COLUMN NAME"].ToString();
var queryResults = string.Format("\"{0}\",\"{1}\",\"{2}\"",
rdr["Name"].ToString(),
rdr["Address"}.ToString(),
rdr["Phone Number"].ToString()
);
sbRtn.AppendLine(queryResults);
}
}
thisConnection.Close();
return File(new System.Text.UTF8Encoding().GetBytes(sbRtn.ToString()), "text/csv", "FileName.csv");
}
From a List
/* To help illustrate */
public static List<Person> list = new List<Person>();
/* To help illustrate */
public class Person
{
public string name;
public string address;
public string phoneNumber;
}
/* The important part */
public FileContentResults DownloadCSV()
{
StringBuilder sbRtn = new StringBuilder();
// If you want headers for your file
var header = string.Format("\"{0}\",\"{1}\",\"{2}\"",
"Name",
"Address",
"Phone Number"
);
sbRtn.AppendLine(header);
foreach (var item in list)
{
var listResults = string.Format("\"{0}\",\"{1}\",\"{2}\"",
item.name,
item.address,
item.phoneNumber
);
sbRtn.AppendLine(listResults);
}
}
return File(new System.Text.UTF8Encoding().GetBytes(sbRtn.ToString()), "text/csv", "FileName.csv");
}
Hopefully this is helpful.
This is a simple tutorial on creating csv files using C# that you will be able to edit and expand on to fit your own needs.
First you’ll need to create a new Visual Studio C# console application, there are steps to follow to do this.
The example code will create a csv file called MyTest.csv in the location you specify. The contents of the file should be 3 named columns with text in the first 3 rows.
https://tidbytez.com/2018/02/06/how-to-create-a-csv-file-with-c/
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;
namespace CreateCsv
{
class Program
{
static void Main()
{
// Set the path and filename variable "path", filename being MyTest.csv in this example.
// Change SomeGuy for your username.
string path = #"C:\Users\SomeGuy\Desktop\MyTest.csv";
// Set the variable "delimiter" to ", ".
string delimiter = ", ";
// This text is added only once to the file.
if (!File.Exists(path))
{
// Create a file to write to.
string createText = "Column 1 Name" + delimiter + "Column 2 Name" + delimiter + "Column 3 Name" + delimiter + Environment.NewLine;
File.WriteAllText(path, createText);
}
// This text is always added, making the file longer over time
// if it is not deleted.
string appendText = "This is text for Column 1" + delimiter + "This is text for Column 2" + delimiter + "This is text for Column 3" + delimiter + Environment.NewLine;
File.AppendAllText(path, appendText);
// Open the file to read from.
string readText = File.ReadAllText(path);
Console.WriteLine(readText);
}
}
}
public static class Extensions
{
public static void WriteCSVLine(this StreamWriter writer, IEnumerable<string> fields)
{
const string q = #"""";
writer.WriteLine(string.Join(",",
fields.Select(
v => (v.Contains(',') || v.Contains('"') || v.Contains('\n') || v.Contains('\r')) ? $"{q}{v.Replace(q, q + q)}{q}" : v
)));
}
public static void WriteCSVLine(this StreamWriter writer, params string[] fields) => WriteCSVLine(writer, (IEnumerable<string>)fields);
}
This should allow you to write a csv file quite simply. Usage:
StreamWriter writer = new ("myfile.csv");
writer.WriteCSVLine("A", "B"); // A,B
Here is another open source library to create CSV file easily, Cinchoo ETL
List<dynamic> objs = new List<dynamic>();
dynamic rec1 = new ExpandoObject();
rec1.Id = 10;
rec1.Name = #"Mark";
rec1.JoinedDate = new DateTime(2001, 2, 2);
rec1.IsActive = true;
rec1.Salary = new ChoCurrency(100000);
objs.Add(rec1);
dynamic rec2 = new ExpandoObject();
rec2.Id = 200;
rec2.Name = "Tom";
rec2.JoinedDate = new DateTime(1990, 10, 23);
rec2.IsActive = false;
rec2.Salary = new ChoCurrency(150000);
objs.Add(rec2);
using (var parser = new ChoCSVWriter("emp.csv").WithFirstLineHeader())
{
parser.Write(objs);
}
For more information, please read the CodeProject article on usage.
One simple way to get rid of the overwriting issue is to use File.AppendText to append line at the end of the file as
void Main()
{
using (System.IO.StreamWriter sw = System.IO.File.AppendText("file.txt"))
{
string first = reader[0].ToString();
string second=image.ToString();
string csv = string.Format("{0},{1}\n", first, second);
sw.WriteLine(csv);
}
}
enter code here
string string_value= string.Empty;
for (int i = 0; i < ur_grid.Rows.Count; i++)
{
for (int j = 0; j < ur_grid.Rows[i].Cells.Count; j++)
{
if (!string.IsNullOrEmpty(ur_grid.Rows[i].Cells[j].Text.ToString()))
{
if (j > 0)
string_value= string_value+ "," + ur_grid.Rows[i].Cells[j].Text.ToString();
else
{
if (string.IsNullOrEmpty(string_value))
string_value= ur_grid.Rows[i].Cells[j].Text.ToString();
else
string_value= string_value+ Environment.NewLine + ur_grid.Rows[i].Cells[j].Text.ToString();
}
}
}
}
string where_to_save_file = #"d:\location\Files\sample.csv";
File.WriteAllText(where_to_save_file, string_value);
string server_path = "/site/Files/sample.csv";
Response.ContentType = ContentType;
Response.AppendHeader("Content-Disposition", "attachment; filename=" + Path.GetFileName(server_path));
Response.WriteFile(server_path);
Response.End();
You might just have to add a line feed "\n\r".
I have 2 procedures in SQL and their results should be dumped as a CSV file from C#. I’m able to get the results of 1 procedure , but I’m clueless as to how to go about adding the results from the 2nd procedure.
Procedure 1. GetCSVData
Procedure 2 . GetHeader
The below C# code successfully gets data into CSV from procedure 1 ('GetCSVData').
Please help me in integrating the data from Procedure2 (“GetHeader”) into ‘GetCSVData’ and write it to the same CSV file.
My C# code:
public string GetCSVData(string SId, string TotalRow)
{ try
{
Sql v = new Sql("Block_Rpt_CSV");
v.Add("SId",SId);
v.Add("TotalRow",TotalRow);
v.Run();
DataTable dt=new DataTable();
dt.Clear();
dt.Columns.Add("a", typeof(String));
dt.Columns.Add("b", typeof(String));
dt.Columns.Add("c", typeof(String));
foreach (System.Data.DataRow item in v.Results.Rows)
{
dt.Rows.Add(item.GetString("Name"),item.GetString("Id"),
item.GetString("Class")
}
dt.AcceptChanges();
string csvData = DataTableToCSVFile(dt, SId, TotalRow);
System.Web.HttpResponse response = System.Web.HttpContext.Current.Response;
response.ClearContent();
response.Clear();
string filename = "CsvView.csv";
response.ContentType = "text/csv";
response.AddHeader("Content-Disposition", "attachment;filename=\"" + filename + "\";");
HttpContext.Current.Response.AddHeader("Content-Length", csvData.Length.ToString());
response.Write(csvData);
response.Flush();
response.End();
AjaxBuilder r = new AjaxBuilder();
r.Add("GetCSVData", "Success");
return r.ToString();
}
catch (Exception e)
{
AjaxBuilder r = new AjaxBuilder();
r.Add("GetCSVData", "Failed");
r.Add("Exception_Message", e.Message);
r.Add("Exception_StackTrace", e.StackTrace);
return r.ToString();
}
}
#Harvey : Sorry I missed seeing your post until now. Thanks for the code. However I've been struggling with this before I saw your's. Can you please take a look and at my code and see if I can get it to work? Else I'll use your code. As of now all my 20 columns heads are displayed in my CSV and obviously the data in each column does not match.
private string DataTableToCSVFile(DataTable dt, string SId, string TotalRow)
{ DataTable dtExcel = dt;
StringBuilder sb = new StringBuilder();
sb.Append("CSV Data");
sb.Append("\n");
foreach (DataColumn column in dtExcel.Columns)
{
sb.Append(column.ColumnName + ",");
}
sb.Append("\n");
foreach (DataRow row in dtExcel.Rows)
{
for (int i = 0; i < dtExcel.Columns.Count; i++)
{
sb.Append(row[i].ToString() + ",");
}
sb.Append("\n");
}
return sb.ToString();
}
You can make your DataTable object as global and then use that same object in both the functions.
Run whichever you want first and insert the columns and records into id. And then, run the second one and insert the columns and records into it accordingly.
You can also use two separate DataTable objects for each function and then merge them after you have received results in both.
Also, make sure you write the actual CSV generation code at the end afterwards when both your functions are called.
UPDATE :
Here's how you can write your datatable values on a CSV file :
string csvPath = System.Web.Hosting.HostingEnvironment.MapPath("pathToCSV.csv");
StreamWriter sw = new StreamWriter(csvPath, false);
if (dtDataTablesList.Rows.Count > 0)
{
//First we will write the headers.
int iColCount = dtDataTablesList.Columns.Count;
for (int i = 0; i < iColCount; i++)
{
sw.Write(dtDataTablesList.Columns[i]);
if (i < iColCount - 1)
{
sw.Write(",");
}
}
sw.Write(sw.NewLine);
// Now write all the rows.
foreach (DataRow dr in dtDataTablesList.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);
}
}
Now here, since you want to split some columns and write them first and then the others, you will have to modify the for condition a bit here and I think that should be fine with you.
Hope this gives an idea of how to progress with this.
whats the best way to export a Datagrid to excel? I have no experience whatsoever in exporting datagrid to excel, so i want to know how you guys export datagrid to excel.
i read that there are a lot of ways, but i am thinking to just make a simple export excel to datagrid function.i am using asp.net C#
cheers..
The simplest way is to simply write either csv, or html (in particular, a <table><tr><td>...</td></tr>...</table>) to the output, and simply pretend that it is in excel format via the content-type header. Excel will happily load either; csv is simpler...
Here's a similar example (it actually takes an IEnumerable, but it would be similar from any source (such as a DataTable, looping over the rows).
public static void WriteCsv(string[] headers, IEnumerable<string[]> data, string filename)
{
if (data == null) throw new ArgumentNullException("data");
if (string.IsNullOrEmpty(filename)) filename = "export.csv";
HttpResponse resp = System.Web.HttpContext.Current.Response;
resp.Clear();
// remove this line if you don't want to prompt the user to save the file
resp.AddHeader("Content-Disposition", "attachment;filename=" + filename);
// if not saving, try: "application/ms-excel"
resp.ContentType = "text/csv";
string csv = GetCsv(headers, data);
byte[] buffer = resp.ContentEncoding.GetBytes(csv);
resp.AddHeader("Content-Length", buffer.Length.ToString());
resp.BinaryWrite(buffer);
resp.End();
}
static void WriteRow(string[] row, StringBuilder destination)
{
if (row == null) return;
int fields = row.Length;
for (int i = 0; i < fields; i++)
{
string field = row[i];
if (i > 0)
{
destination.Append(',');
}
if (string.IsNullOrEmpty(field)) continue; // empty field
bool quote = false;
if (field.Contains("\""))
{
// if contains quotes, then needs quoting and escaping
quote = true;
field = field.Replace("\"", "\"\"");
}
else
{
// commas, line-breaks, and leading-trailing space also require quoting
if (field.Contains(",") || field.Contains("\n") || field.Contains("\r")
|| field.StartsWith(" ") || field.EndsWith(" "))
{
quote = true;
}
}
if (quote)
{
destination.Append('\"');
destination.Append(field);
destination.Append('\"');
}
else
{
destination.Append(field);
}
}
destination.AppendLine();
}
static string GetCsv(string[] headers, IEnumerable<string[]> data)
{
StringBuilder sb = new StringBuilder();
if (data == null) throw new ArgumentNullException("data");
WriteRow(headers, sb);
foreach (string[] row in data)
{
WriteRow(row, sb);
}
return sb.ToString();
}
You can do it in this way:
private void ExportButton_Click(object sender, System.EventArgs e)
{
Response.Clear();
Response.Buffer = true;
Response.ContentType = "application/vnd.ms-excel";
Response.Charset = "";
this.EnableViewState = false;
System.IO.StringWriter oStringWriter = new System.IO.StringWriter();
System.Web.UI.HtmlTextWriter oHtmlTextWriter = new System.Web.UI.HtmlTextWriter(oStringWriter);
this.ClearControls(dataGrid);
dataGrid.RenderControl(oHtmlTextWriter);
Response.Write(oStringWriter.ToString());
Response.End();
}
Complete example here.
SpreadsheetGear for .NET will do it.
You can see live ASP.NET samples with C# and VB source code here. Several of these samples demonstrate converting a DataSet or DataTable to Excel - and you can easily get a DataSet or DataTable from a DataGrid. You can download the free trial here if you want to try it yourself.
Disclaimer: I own SpreadsheetGear LLC
I can export my radgrid to an excel file but I want to add some more info into the sheet.
If it is possible, I would appreciate for a tutorial/sample code for doing a custom excel file generation.
<tel:radgrid runat="server" id="mygrid" skinid="RadGrid_Search_Standard">
<ExportSettings HideStructureColumns="true" />
</tel:radgrid>
Grid is databound with some datatable and I need to add some data
to add some strings above
mygrid.MasterTableView.ExportToWord()
Here's some code that I use with a Telerik Grid, rather than using the ExportToExcel function they've provided I created my own button that fires it's own export event.
I have a function (not included) called getDataSource that I use to populate the grid, you could override this or create your own to fetch the data into a DataTable and add any rows/columns/data as you see fit.
//export button calls this
private void ExportReport()
{
SetPublicVariables();
System.Data.DataTable dt = GetDataSource(false);
string exportData = buildCSVExportString(dt);
string filename = string.Format("{0} - {1}.csv",
(Master as MasterPages.Drilldown).Titlelbl.Text, CampaignTitle);
if (filename.Length > 255) filename = filename.Substring(0, 255);
ExportCSV(exportData, filename);
}
//build a string CSV
public static string buildCSVExportString(DataTable exportDT)
{
StringBuilder exportData = new StringBuilder();
// get headers.
int iColCount = exportDT.Columns.Count;
for (int i = 0; i < iColCount; i++)
{
exportData.Append(exportDT.Columns[i].ToString());
if (i < iColCount - 1)
{
exportData.Append(",");
}
}
exportData.Append(System.Environment.NewLine);
// get rows.
foreach (DataRow dr in exportDT.Rows)
{
for (int i = 0; i < iColCount; i++)
{
if (!Convert.IsDBNull(dr[i]))
{
//If the variable is a string it potentially has charaters that can't be parsed properly.
//this fixes the comma issue(which adds aditional columns). Replace and escape " with "".
if (dr[i] is string)
exportData.Append(String.Format(#"""{0}""", ((string)dr[i]).Replace("\"", #"""""")));
else
exportData.Append(dr[i].ToString());
}
if (i < iColCount - 1)
{
exportData.Append(",");
}
}
exportData.Append(System.Environment.NewLine);
}
return exportData.ToString();
}
public void ExportCSV(string content, string filename)
{
filename = RemoveIllegalPathChars(filename);
HttpResponse Response = HttpContext.Current.Response;
string ext = System.IO.Path.GetExtension(filename);
Response.ClearHeaders();
Response.AddHeader("Content-Disposition", string.Format("attachment;filename=\"{0}\"", filename));
Response.ContentType = "text/csv; charset-UTF-8;";
Response.Clear();
Response.Write(content);
Response.End();
}
A possible way would be to modify the HTML code just before exporting. Here is how.
protected override void OnInit(EventArgs e)
{
base.OnInit(e);
RadGridName.GridExporting += (s, a) =>
{
string myHtmlCode = "<span>My HTML code goes here</span>";
a.ExportOutput = a.ExportOutput.Replace("<body>", "<body>" + myHtmlCode);
};
}
This should work for both Excel (not ExcelML) and Word.
Good luck
The only thing you need to do is add your additional page info to the ExportOutput of your arg
void yourRadGridID_GridExporting(object sender, GridExportingArgs e)
{
string additionalPageInfo= "your html code for the additional page info goes here";
e.ExportOutput = e.ExportOutput.Replace("`<body>`", "`<body>`" + additionalPageInfo);
}
whats the best way to export a Datagrid to excel? I have no experience whatsoever in exporting datagrid to excel, so i want to know how you guys export datagrid to excel.
i read that there are a lot of ways, but i am thinking to just make a simple export excel to datagrid function.i am using asp.net C#
cheers..
The simplest way is to simply write either csv, or html (in particular, a <table><tr><td>...</td></tr>...</table>) to the output, and simply pretend that it is in excel format via the content-type header. Excel will happily load either; csv is simpler...
Here's a similar example (it actually takes an IEnumerable, but it would be similar from any source (such as a DataTable, looping over the rows).
public static void WriteCsv(string[] headers, IEnumerable<string[]> data, string filename)
{
if (data == null) throw new ArgumentNullException("data");
if (string.IsNullOrEmpty(filename)) filename = "export.csv";
HttpResponse resp = System.Web.HttpContext.Current.Response;
resp.Clear();
// remove this line if you don't want to prompt the user to save the file
resp.AddHeader("Content-Disposition", "attachment;filename=" + filename);
// if not saving, try: "application/ms-excel"
resp.ContentType = "text/csv";
string csv = GetCsv(headers, data);
byte[] buffer = resp.ContentEncoding.GetBytes(csv);
resp.AddHeader("Content-Length", buffer.Length.ToString());
resp.BinaryWrite(buffer);
resp.End();
}
static void WriteRow(string[] row, StringBuilder destination)
{
if (row == null) return;
int fields = row.Length;
for (int i = 0; i < fields; i++)
{
string field = row[i];
if (i > 0)
{
destination.Append(',');
}
if (string.IsNullOrEmpty(field)) continue; // empty field
bool quote = false;
if (field.Contains("\""))
{
// if contains quotes, then needs quoting and escaping
quote = true;
field = field.Replace("\"", "\"\"");
}
else
{
// commas, line-breaks, and leading-trailing space also require quoting
if (field.Contains(",") || field.Contains("\n") || field.Contains("\r")
|| field.StartsWith(" ") || field.EndsWith(" "))
{
quote = true;
}
}
if (quote)
{
destination.Append('\"');
destination.Append(field);
destination.Append('\"');
}
else
{
destination.Append(field);
}
}
destination.AppendLine();
}
static string GetCsv(string[] headers, IEnumerable<string[]> data)
{
StringBuilder sb = new StringBuilder();
if (data == null) throw new ArgumentNullException("data");
WriteRow(headers, sb);
foreach (string[] row in data)
{
WriteRow(row, sb);
}
return sb.ToString();
}
You can do it in this way:
private void ExportButton_Click(object sender, System.EventArgs e)
{
Response.Clear();
Response.Buffer = true;
Response.ContentType = "application/vnd.ms-excel";
Response.Charset = "";
this.EnableViewState = false;
System.IO.StringWriter oStringWriter = new System.IO.StringWriter();
System.Web.UI.HtmlTextWriter oHtmlTextWriter = new System.Web.UI.HtmlTextWriter(oStringWriter);
this.ClearControls(dataGrid);
dataGrid.RenderControl(oHtmlTextWriter);
Response.Write(oStringWriter.ToString());
Response.End();
}
Complete example here.
SpreadsheetGear for .NET will do it.
You can see live ASP.NET samples with C# and VB source code here. Several of these samples demonstrate converting a DataSet or DataTable to Excel - and you can easily get a DataSet or DataTable from a DataGrid. You can download the free trial here if you want to try it yourself.
Disclaimer: I own SpreadsheetGear LLC