Web Forms :: How To Export CSV Data Passed To Web Method Get Exported Into Excel

I have comma separated data on client side [Since my columns and rows are dynamic along with dynamic control inside it which are not accessible in backend due to viewstate issue of dynamic controls],

So I am passing CSV string to Web Method as and want to get Excel file out of it.

I tried following code but it is not exporting the file.

[System.Web.Services.WebMethod]
public static void CSV2Excel(string csv){
HttpContext.Current.Response.Clear();
HttpContext.Current.Response.AddHeader("content-disposition", "attachment;filename=FileName.csv");
HttpContext.Current.Response.Charset = "";
HttpContext.Current.Response.ContentType = "application/octet-stream";
HttpContext.Current.Response.Write(csv);
HttpContext.Current.Response.End();
}