Question

Well, this certainly might have not been asked before.

I have a method that returns me an IQueryable, the client requirement is one specific example we should export that to excel without showing the results in a gridview.

Any idea?

string strSql = BuildQuery();
            try
            {
                var list = RequestBaseBL.GetRequestByCustomQuery(strSql, DdlRequestType.SelectedValue).ToList();

Answer 1

to export in excel have a look here:

http://epplus.codeplex.com/releases/view/42439

then you can create your own class to generate excel export for IEnumerable

here some hint (these are part of more large object so only hints, nothing compiling surely) at the possible from one of my projects:

 public interface IExcelReporting : IServiceObject
    {
        ColumnsExcel Columns { get; }

        void SetDatasource(IEnumerable datasource);
        void SetHeaderLabelMerge(int columnMerge);
        void AddHeader(string label, string value);
        Byte[] ExportToExcel(string title, string author, DateTime date);
    }

an example of implementation :

  public Byte[] ExportToExcel(string title, string author, DateTime date)
    {
        ExcelPackage package = new ExcelPackage();

        ExcelWorksheet worksheet = package.Workbook.Worksheets.Add(title);

if (_Columns != null)
            {

                Dictionary<int, Func<object, string>> internalMappingGetter = new Dictionary<int, Func<object, string>>();

                //create the Header of the body
                foreach (ColumnExcel entity in _Columns)
                {
                    worksheet.Cells[RowIndex, ColumnIndex].Value = entity.HeaderName;
                    worksheet.Cells[RowIndex, ColumnIndex].Style.WrapText = true;
                    BorderCell(worksheet.Cells[RowIndex, ColumnIndex]);
                    worksheet.Column(ColumnIndex).Width = entity.Width;
                    ColumnIndex++;
                }

                RowIndex++;

                if (_DataSource != null)
                {
                    foreach (Object o in _DataSource)
                    {
                        ColumnIndex = 1;
                        foreach (ColumnExcel column in _Columns)
                        {
                            column.Apply(worksheet.Cells[RowIndex, ColumnIndex], o);
                            worksheet.Column(ColumnIndex).BestFit = true;
                            worksheet.Cells[RowIndex, ColumnIndex].Style.WrapText = true;
                            //BorderCell(worksheet.Cells[RowIndex, ColumnIndex]);
                            ColumnIndex++;
                        }
                        RowIndex++;
                    }
                }

and the column class:

public class ColumnsExcel : IEnumerable
    {
        List<ColumnExcel> _Columns;

        public ColumnsExcel()
        {
            _Columns = new List<ColumnExcel>();
        }


        public void AddInt(Func<object,int> getValue, string headerName, int width, string format)
        {
            ColumnExcel entity = new ColumnExcelInt(headerName, width, format, getValue);
            _Columns.Add(entity);
        }

        public void AddString(Func<object, string> getValue, string headerName, int width )
        {
            ColumnExcel entity = new ColumnExcelstring(headerName, width, getValue);
            _Columns.Add(entity);
        }

        public void AddDateTime(Func<object, DateTime?> getValue, string headerName, int width, string format)
        {
            ColumnExcel entity = new ColumnExcelDateTime(headerName, width, format, getValue);
            _Columns.Add(entity);
        }

        public void AddDecimal(Func<object, decimal> getValue, string headerName, int width, string format)
        {
            ColumnExcel entity = new ColumnExcelDecimal(headerName, width, format, getValue);
            _Columns.Add(entity);
        }

        public IEnumerator GetEnumerator()
        {
            return _Columns.GetEnumerator();
        }
    }

and its use :

 //prepare the Ienumerable<MyObject>
 var interventi = GetInterventoSchedeConsuntivi()

 //prepare the report
 IExcelReporting report = ReportingFactory.GetInstance();
 report.SetDatasource(interventi);
 report.AddHeader("Lotto:", lotto);

 report.Columns.AddString((object v) => ((InterventoSchedeConsuntiviView)v).Lotto, "Lotto", 20);

using (System.IO.Stream s = File.Create(filepath))
                    {
                        byte[] csv = report.ExportToExcel(("titleFile", string.Empty, Servizi.DataOra.Now);
                        s.Write(csv, 0, csv.Length);
                    }