Exporting to excel loses the date format

Question

I am exporting the contents of SP to excel. One of the columns brings the date format as 08/2015 but when exporting to excel, the format gets changed to Aug-2015.

I

Answer 1

I don't really understand a fair bit of the code (not fluent in asp.net) but I will say that if you want to force text in an excel sheet you need to define the target area as text before putting your data in there.

If my understanding of the code is correct this:

response.Write(style);

Needs to be before this.

dgrExport.RenderControl(htmlWrite);

Edit: Perhaps an alternate solution

The bit of google code you have found sets the format of the cells as text. In all likelyhood you want excel to treat the date as a date which has a display format of MM/YYYY.

maybe try replacing this:

string style = @"<style> .text { mso-number-format:\@; } </style> "

with

string style = @"<style> .text { mso-number-format:\mm/yyyy; } </style> "

I am not sure if / or \ is an escape character in ASP.net so the exact snytax might be different. In excel terms number format @ means text and mm/yyyy will mean a date with the display format that you want.

Answer 2

Problem is not with the Date format, Excel converts the data as per the DataType (Default is GENERAL) of CELL. To prevent the data conversion you have to provide the data type (TEXT) along with the data.

you have used the correct code, but style sheet .text is not applied on your data. Apply the style sheet on ALL the <TD> tags. It will 100% work and will retain your data as is you will provide (Date- 08/2015, 0001 or any data).

string style = @"<style> TD { mso-number-format:\@; } </style> ";

Answer 3

Here is some sample code.

Response.AddHeader("content-disposition", "attachment; filename=Report.xls");
Response.Charset = "";
Response.ContentType = "application/vnd.xls";
System.IO.StringWriter stringWrite = new System.IO.StringWriter();
System.Web.UI.HtmlTextWriter htmlWrite = new HtmlTextWriter(stringWrite);
DataGrid g = new DataGrid();
DataTable d = new System.Data.DataTable();
d = (DataTable)Session["ReportData"];        
g.DataSource = d;
g.DataBind();       
foreach (DataGridItem i in g.Items)
{
    foreach (TableCell tc in i.Cells)
        tc.Attributes.Add("class", "text");
}
g.RenderControl(htmlWrite);
string style = @"<style> .text { mso-number-format:\@; } </style> ";
Response.Write(style);
Response.Write(stringWrite.ToString());
Response.End();