I need to export a really large csv file(~100MB). On the internet I found a similar code and implemented it for my case:
public class CSVExporter
{
public static void WriteToCSV(List<Person> personList)
{
string attachment = "attachment; filename=PersonList.csv";
HttpContext.Current.Response.Clear();
HttpContext.Current.Response.ClearHeaders();
HttpContext.Current.Response.ClearContent();
HttpContext.Current.Response.AddHeader("content-disposition", attachment);
HttpContext.Current.Response.ContentType = "text/csv";
HttpContext.Current.Response.AddHeader("Pragma", "public");
WriteColumnName();
foreach (Person person in personList)
{
WriteUserInfo(person);
}
HttpContext.Current.Response.End();
}
private static void WriteUserInfo(Person person)
{
StringBuilder stringBuilder = new StringBuilder();
AddComma(person.Name, stringBuilder);
AddComma(person.Family, stringBuilder);
AddComma(person.Age.ToString(), stringBuilder);
AddComma(string.Format("{0:C2}", person.Salary), stringBuilder);
HttpContext.Current.Response.Write(stringBuilder.ToString());
HttpContext.Current.Response.Write(Environment.NewLine);
}
private static void AddComma(string value, StringBuilder stringBuilder)
{
stringBuilder.Append(value.Replace(',', ' '));
stringBuilder.Append(", ");
}
private static void WriteColumnName()
{
string columnNames = "Name, Family, Age, Salary";
HttpContext.Current.Response.Write(columnNames);
HttpContext.Current.Response.Write(Environment.NewLine);
}
}
The problem is I want to start the download before(!) the whole CSV is constructed. Why is not it working like I suppose it too and what must I change?
You could probably force the response to be flushed to the client by using
Response.Flush();
after each record is appended to the stream. Please refer to this article for more details:
http://support.microsoft.com/kb/812406
Related
I'm trying to export data as a CSV file in C#, but the problems starts when i'm trying to import the csv file in excel.
In excel I'm using the function "import from text", and afterwards I set the delimiter to semicolon
My problem is that some of the columns have linebreaks and then the import in excel is wrong.
I have tried with single and doubles quotes with no luck.
I have searched for a solution, but has not found one yet.
Anyone knows if lumenworks has a export function, because i'm using this for the import function
The problem is the export function and the linebreaks are required.
if (list.Any())
{
result = list.Select(i => new
{
i.Product.ProductIdentifier,
i.Product.Header,
body = string.Format("\"" + "{0}" + "\"", i.Product.Body),
Active = i.Product.Active ? 1 : 0,
Approved = i.Product.Approved ? 1 : 0,
i.Product.Sort,
i.Product.MetaDescription,
i.Product.MetaKeywords,
i.CatalogMenuItemContentItemId
}).ToList().ToCsv(";");
}
string attachment = "attachment; filename=myfile.csv";
HttpContext.Current.Response.Clear();
HttpContext.Current.Response.ClearHeaders();
HttpContext.Current.Response.ClearContent();
HttpContext.Current.Response.AddHeader("content-disposition", attachment);
HttpContext.Current.Response.ContentType = "text/csv";
HttpContext.Current.Response.ContentEncoding = System.Text.Encoding.GetEncoding("ISO-8859-1");
HttpContext.Current.Response.Write(result);
HttpContext.Current.Response.End();
public static string ToCsv<T>(this IEnumerable<T> items, string seperator = ",")
where T : class
{
var csvBuilder = new StringBuilder();
var properties = typeof(T).GetProperties();
foreach (T item in items)
{
string line = string.Join(seperator, properties.Select(p => p.GetValue(item, null).ToCsvValue()).ToArray());
csvBuilder.AppendLine(line);
}
return csvBuilder.ToString();
}
private static string ToCsvValue<T>(this T item)
{
return string.Format("{0}", HttpUtility.HtmlDecode(item.ToString()));
}
Any idea ?
What am I doing wrong here?
I am trying to export a list of customers to a downloadable csv file, that can be viewed in Excel
Currently I do not care about buttons and listeners, I just want to generate the actual csv file.
public class CSVExporter
{
public static void WriteToCSV(List<CustomerInformation> customerList)
{
string attachment = "attachment; filename=CustomerList.csv";
HttpContext.Current.Response.Clear();
HttpContext.Current.Response.ClearHeaders();
HttpContext.Current.Response.ClearContent();
HttpContext.Current.Response.AddHeader("content-disposition", attachment);
HttpContext.Current.Response.ContentType = "text/csv";
HttpContext.Current.Response.AddHeader("Pragma", "public");
WriteColumnName();
foreach (CustomerInformation customer in customerList)
{
WriteUserInfo(customer);
}
HttpContext.Current.Response.End();
}
private static void WriteUserInfo(CustomerInformation customer)
{
StringBuilder stringBuilder = new StringBuilder();
AddComma(customer.name, stringBuilder);
AddComma(customer.email, stringBuilder);
AddComma(customer.username, stringBuilder);
AddComma(customer.mobilenumber, stringBuilder);
AddComma(customer.dateCreated, stringBuilder);
AddComma(customer.birthday, stringBuilder);
HttpContext.Current.Response.Write(stringBuilder.ToString());
HttpContext.Current.Response.Write(Environment.NewLine);
}
private static void AddComma(string value, StringBuilder stringBuilder)
{
stringBuilder.Append(value.Replace(',', ' '));
stringBuilder.Append(", ");
}
private static void WriteColumnName()
{
string columnNames = "Name, Email, Username, Mobile number, Date created, Birthdate";
HttpContext.Current.Response.Write(columnNames);
HttpContext.Current.Response.Write(Environment.NewLine);
}
}
When I run the code, I get this:
I've simply used this
public HttpResponseMessage DownloadCsv()
{
const string csv = "mobile,type,amount\r\n123456789,0,200\r\n56987459,0,200";
var result = new HttpResponseMessage(HttpStatusCode.OK) {Content = new StringContent(csv)};
result.Content.Headers.ContentType = new MediaTypeHeaderValue("text/csv");
result.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment")
{
FileName = "Sample.csv"
};
return result;
}
I am exporting a CSV file from an ASP .NET page but somehow it contains HTML code and the data that are supposed to be exported (ie. 29 rows) are not complete (ie from supposedly 29 rows, only 17 shows up, and then HTML all the way down).
Here are my codes:
private void WriteToCSV()
{
var clientId = int.Parse(ddlClients.SelectedValue);
var taskTypeId = int.Parse(ddlTaskType.SelectedValue);
var mtComponent = new MainTableComponent();
var data = mtComponent.GetMainTableRecords(clientId, 0, taskTypeId);
if (data == null || data.Count == 0)
{
ShowAlertMessage("No available data to export.");
return;
}
var callerId = GetClientList().FirstOrDefault(x => x.ClientId == clientId).CallerId;
string attachment = string.Concat("attachment; filename=CallList_", ddlClients.SelectedItem.Text,
"_", ddlTaskType.SelectedItem.Text, "_", DateTime.Now.ToString("yyyyMMdd"), ".csv");
HttpContext.Current.Response.Clear();
HttpContext.Current.Response.ClearHeaders();
HttpContext.Current.Response.ClearContent();
HttpContext.Current.Response.AddHeader("content-disposition", attachment);
HttpContext.Current.Response.ContentType = "text/csv";
HttpContext.Current.Response.AddHeader("Pragma", "public");
HttpContext.Current.Response.Write("row,phone1,phone2,phone3,caller_id");
foreach (var d in data)
WriteUserInfo(d, callerId);
HttpContext.Current.Response.End();
}
private void WriteUserInfo(MainTableEntity person, string callerId)
{
HttpContext.Current.Response.Write(Environment.NewLine);
StringBuilder stringBuilder = new StringBuilder();
AddComma(person.RowNumber.ToString(), stringBuilder);
AddComma(FormatNumber(person.MobileNumber), stringBuilder);
AddComma("", stringBuilder);
AddComma("", stringBuilder);
AddComma(callerId, stringBuilder);
stringBuilder.Remove(stringBuilder.Length - 1, 1);
HttpContext.Current.Response.Write(stringBuilder.ToString());
}
private void AddComma(string value, StringBuilder stringBuilder)
{
value.Replace(",", "");
stringBuilder.Append(value).Append(",");
}
private string FormatNumber(string number)
{
if (string.IsNullOrWhiteSpace(number))
return null;
string n = number.Replace('-', ' ').Replace(" ", "").Trim();
return n;
}
The funny thing is, this does not happen on my local machine and on our test environment. It only happens in our production environment.
Any help is appreciated. Thank you very much!
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
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