将数据表保存到C＃中具有100k行的大型Excel文件中

Question

I working with windows application and processing large excel file. I need to save 100k rows from datatable to excel file.

Currently my create excel function only support 65,500 rows only?

But I need to save excel file more than that. Is it possible?

If yes then, Kindly give the source?

Here is my code

    public static void ExportDataSetToExcel(DataTable dt, int index, string strFilePathName)
    {
        Console.WriteLine("Creating Output Excel file");              
        string fileFomat = getExcelFileName(index) + (DateTime.Now.ToString("yyyyMMddTHHmmss"));           
        Microsoft.Office.Interop.Excel.Application objXL = null;           
        Microsoft.Office.Interop.Excel.Workbook objWB = null;
        try
        {

            objXL = new Microsoft.Office.Interop.Excel.Application();                
            objWB = objXL.Workbooks.Add(1);               
            int sheetcount = 1; 

            Microsoft.Office.Interop.Excel.Worksheet objSHT = (Microsoft.Office.Interop.Excel.Worksheet)objWB.Sheets.Add();                
            Microsoft.Office.Interop.Excel.Range cells = objSHT.Cells;                
            cells.NumberFormat = "@"; 
            //formatRange = objSHT.get_Range("b1",Type.Missing);                
            //formatRange.EntireRow.Font.Bold = true;

            objSHT.Name = "RunOrderSheet";                            
            for (int j = 0; j < dt.Rows.Count; j++)
            {
                for (int i = 0; i < dt.Columns.Count; i++)  
                {
                    //Condition to put column names in 1st row
                    //Excel work book indexes start from 1,1 and not 0,0
                    if (j == 0)
                    {
                        objSHT.Cells[1, i + 1] = dt.Columns[i].ColumnName.ToString();
                    }
                    //Writing down data
                    objSHT.Cells[j + 2, i + 1] = dt.Rows[j][i].ToString();
                }
            }                
            sheetcount++;
            objWB.Saved = true;
            objWB.SaveCopyAs(strFilePathName.Trim() + fileFomat.Trim() + ".xlsx");               
            objWB.Close();                
            objXL.Quit();
            Console.WriteLine("Process done");
        }
        catch (Exception ex)
        {
            objWB.Saved = true;              
            objWB.Close();               
            objXL.Quit();
            log.Error(ex.Message);          
        }
    }

Answer 1

Excel and the COM interface with C# absolutely will support more than 65k lines. Just to prove that it's possible, run the following code:

public static void ExportDataSetToExcel()
{
    Excel.Application objXL = null;
    Excel.Workbook objWB = null;

    objXL = new Microsoft.Office.Interop.Excel.Application();
    objXL.Visible = true;

    objWB = objXL.Workbooks.Add(1);
    Excel.Worksheet objSHT = objWB.Sheets.Add();

    for (int row = 1; row < 100000; row++)
    {
        objSHT.Cells[row, 1].Value2 = row;
    }

    objWB.SaveAs("c:\test\test.xlsx", Excel.XlFileFormat.xlOpenXMLWorkbook);
    objWB.Close();
    objXL.Quit();
}

Which leads me to several possibilities as to what your issue might be, in order of my suspicions (first being what I think is the most likely):

1. Since you have a try/catch block that is very nicely trapping errors and making sure that anything that happens within your loop while still saving the file, something is tripping the proverbial circuit breaker. While I don't see any glaring errors, it could be anything. Put a breakpoint within the catch block and see what ex contains. Also, make note of the specific record that is causing the error so you can step through just that one record and see where it occurs.

2. I noticed you are using SaveCopyAs rather than SaveAs . SaveCopyAs automatically saves in the exact same format as the original. I would think your Excel comes up with the default xlsx , but I certainly can't guarantee that. Using SaveAs with the explicit file format will guarantee it is saved in a format that supports more than 65k lines: .

objWB.SaveAs("c:\\test\\test.xlsx", Excel.XlFileFormat.xlOpenXMLWorkbook);

Without knowing how large your datatable is, it might simply be a memory issue also that's tripping the try/catch.