c# (WinForms-App) export DataSet to Excel

Question

I need a solution to export a dataset to an excel file without any asp code (HttpResonpsne...) but i did not find a good example to do this...

Best thanks in advance

Answer 1

using XL = Microsoft.Office.Interop.Excel;
using System.Reflection;

public static void Datasource(DataTable dt)
{
    XL.Application oXL;
    XL._Workbook oWB;
    XL._Worksheet oSheet;
    XL.Range oRng;

    try
    {
        oXL = new XL.Application();
        Application.DoEvents();
        oXL.Visible = false;

        //Get a new workbook.
        oWB = (XL._Workbook)(oXL.Workbooks.Add(Missing.Value));
        oSheet = (XL._Worksheet)oWB.ActiveSheet;

        //System.Data.DataTable dtGridData=ds.Tables[0];

        int iRow = 2;
        if (dt.Rows.Count > 0)
        {
            for (int j = 0; j < dt.Columns.Count; j++)
            {
                oSheet.Cells[1, j + 1] = dt.Columns[j].ColumnName;
            }

            // For each row, print the values of each column.
            for (int rowNo = 0; rowNo < dt.Rows.Count; rowNo++)
            {
                for (int colNo = 0; colNo < dt.Columns.Count; colNo++)
                {
                    oSheet.Cells[iRow, colNo + 1] = dt.Rows[rowNo][colNo].ToString();
                }
                iRow++;
            }
            iRow++;
        }
        oRng = oSheet.get_Range("A1", "IV1");
        oRng.EntireColumn.AutoFit();
        oXL.Visible = true;
    }
    catch (Exception theException)
    {
        throw theException;
    }
    finally
    {
        oXL = null;
        oWB = null;
        oSheet = null;
        oRng = null;
    }
}

Import from Excel to datatable:

 DataTable dtTable = new DataTable();
 DataColumn col = new DataColumn("Rfid");
 dtTable.Columns.Add(col);
 DataRow drRow;

 Microsoft.Office.Interop.Excel.Application ExcelObj =
        new Microsoft.Office.Interop.Excel.Application();
 Microsoft.Office.Interop.Excel.Workbook theWorkbook =
            ExcelObj.Workbooks.Open(txt_FilePath.Text, Type.Missing, Type.Missing, Type.Missing, Type.Missing,
                                    Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing,
                                    Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing);
 Microsoft.Office.Interop.Excel.Sheets sheets = theWorkbook.Worksheets;
 try
 {
     for (int sht = 1; sht <= sheets.Count; sht++)
     {
          Microsoft.Office.Interop.Excel.Worksheet worksheet =
                    (Microsoft.Office.Interop.Excel.Worksheet)sheets.get_Item(sht);

          for (int i = 2; i <= worksheet.UsedRange.Rows.Count; i++)
          {
              Microsoft.Office.Interop.Excel.Range range = worksheet.get_Range("A" + i.ToString(), "B" + i.ToString());
              System.Array myvalues = (System.Array)range.Cells.Value2;
              String name = Convert.ToString(myvalues.GetValue(1, 1));
              if (string.IsNullOrEmpty(name) == false)
              {
                  drRow = dtTable.NewRow();
                  drRow["Rfid"] = name;
                  dtTable.Rows.Add(drRow);
              }
          }
              Marshal.ReleaseComObject(worksheet);
              worksheet = null;
        }
    return dtTable;
}
catch
{
    throw;
}
finally
{
   // Marshal.ReleaseComObject(worksheet);
    Marshal.ReleaseComObject(sheets);
    Marshal.ReleaseComObject(theWorkbook);
    Marshal.ReleaseComObject(ExcelObj);
    //worksheet = null;
    sheets = null;
    theWorkbook = null;
    ExcelObj = null;
}