export to excel using existing excel template - export-to-excel

Question

I have used Export to Excel Functionality as below:
var table = getReport(param1, param2, param3);
Response.ClearContent();
Response.AddHeader("content-disposition", "attachment;filename=Report.xls");
Response.ContentType = "application/vnd.ms-excel";
System.Web.UI.WebControls.GridView grd = new System.Web.UI.WebControls.GridView();
grd.DataSource = table; // give datasource here
grd.DataBind();
StringWriter swr = new StringWriter();
HtmlTextWriter tw = new HtmlTextWriter(swr);
grd.RenderControl(tw);
Response.Write(swr.ToString());
Response.End();
return View();
where getReport returns data in table format.
Now this creates a new excel file but i want to use existing excel template to create excel output.
How to to add such template to project and how to bind data with it?

Answer 1

The approach you are using now is writing an HTML string to the Response and setting the ContentType to Excel in the Response headers. This does not create a true Excel file, it just forces the browser to launch the file in Excel, and Excel is able to handle HTML files. There is no way to add a template with this approach.
If you want to use an existing Excel file as a template, you will need to use an API that can create and modify real Excel files, such as OfficeWriter. Here is an example of how to bind your DataTable directly to a template file using OfficeWriter.
using SoftArtisans.OfficeWriter.ExcelWriter;
ExcelTemplate xlt = new ExcelTemplate();
//Open the template file
xlt.Open(pathToTemplateFile);
//Create a DataBindingProperties object
DataBindingProperties props = xlt.CreateDataBindingProperties();
// Call the BindData method, passing the DataTable and a name for the datasource
// which will be referenced in the "data markers" in the template
xlt.BindData(table, "DataSource1", props);
//Call the Process method, which binds the data and generates the output file
xlt.Process();
//Stream the file to the Response
xlt.Save(Response, "Report.xls", false);
Disclaimer: I work for SoftArtisans, the makers of OfficeWriter