保存/创建/导出excel工作表时使用OutOfMemoryException

Question

发展环境：

• 操作系统- Windows 7 64位
• CPU - i5 460 M
• RAM - 8GB
• .NET框架- 4.0
• Excel Microsoft 14.0对象库

我使用Excel-Interop从DataGridView (dgv)导出excel文件。

当我节省了超过15万行

OutOfMemoryException

被扔了。

{
    object[,] valueObjArray = new object[rowCnt, colCnt];
    int rowCnt = dgv.Rows.Count;
    int colCnt = dgv.Columns.Count;

    for (int rowIndex = 0; rowIndex < rowCnt; rowIndex++)
    {
        for (int colIndex = 0; colIndex < colCnt; colIndex++)
        {
            valueObjArray[rowIndex, colIndex] = dgv[colIndex, rowIndex].Value;
        }
    }

    _workSheet.get_Range("A1", Convert.ToChar(colCnt + 64).ToString() + "1").Value2 = headerObjArray;                
    _workSheet.get_Range("A2", Convert.ToChar(colCnt + 64).ToString() + (rowCnt + 1).ToString()).Value2 = valueObjArray;
    _workSheet.get_Range("B2", "B" + (rowCnt+1).ToString()).NumberFormat = "yyyy-mm-dd hh:mm";

    _workBook.SaveAs(path);
}

这是加快我所知道的速度的最好方法。

但是，在监视RAM之后，我认为它会导致内存的增加。当内存使用量达到900 is时引发异常。

我怎样才能抓住这个异常？

Answer 1

试着分批做：

//We will call SaveAs method many times and we don't want to be asked
//if a file should be overwritten every time.
xlApp.DisplayAlerts = false

int rowCnt = dgv.Rows.Count;
int colCnt = dgv.Columns.Count;

int batchSize = 100000; //Try to experiment with other values
int currentRow = 0;

object[,] valueObjArray = new object[batchSize, colCnt];

_workSheet.get_Range("A1", Convert.ToChar(colCnt + 64).ToString() + "1").Value2 = headerObjArray;     

while (currentRow < rowCnt)
{
    for (int rowIndex = 0; rowIndex < batchSize && currentRow + rowIndex < rowCnt; rowIndex++)
    {
        for (int colIndex = 0; colIndex < colCnt; colIndex++)
        {
            valueObjArray[rowIndex, colIndex] =             
            dgv[colIndex, currentRow + rowIndex].Value;
        }
    }

    ws.get_Range("A2", Convert.ToChar(colCnt + 64).ToString() + (currentRow + batchSize + 1).ToString()).Value2 = valueObjArray;
    ws.get_Range("B2", "B" + (currentRow + batchSize + 1).ToString()).NumberFormat = "yyyy-mm-dd hh:mm";

    wb.SaveAs("a.xlsx");

    currentRow += batchSize;
}

我用这种方式节省了一百万行。我用假数据对其进行了测试，因此可能会对一些小的更改/修复进行重新量化。

Answer 2

试着做这个..。

我有大量的数据2拉赫斯及以上。首先，我使用的是excel包，Microsoft.Office.Interop.Excel本地系统运行良好，但是iis(静态ip地址)托管在(worksheet.cell/worksheet.range) OutOfMemoryeException错误数据之后。因此，我使用StreamWriter并写入.xls文件。.xls转换为.xlsx文件后，删除.xls文件。它为我工作。我的英语不好。请理解它。

  private void ExportxlFile(DataTable dt)
    {
        try
        {
            //open file
            //non english not support(ex: Bangla Language)"সালাউদ্দিন স্টোর";
            // StreamWriter wr = new StreamWriter(@"D:\TestBook.xls");

            //non english support(ex: Bangla Language)
            StreamWriter wr = new StreamWriter(@"D:\TestBook.xls", true, Encoding.Unicode); // Encoding.Unicode or Encoding.UTF32

            for (int i = 0; i < dt.Columns.Count; i++)
            {
                wr.Write(dt.Columns[i].ToString().ToUpper() + "\t");
            }

            wr.WriteLine();

            //write rows to excel file
            for (int i = 0; i < (dt.Rows.Count); i++)
            {
                for (int j = 0; j < dt.Columns.Count; j++)
                {
                    if (dt.Rows[i][j] != null)
                    {
                        wr.Write(Convert.ToString(dt.Rows[i][j]) + "\t");
                    }
                    else
                    {
                        wr.Write("\t");
                    }
                }
                //go to next line
                wr.WriteLine();
            }
            //close file
            wr.Close();

            //xls to xlsx convertion
            Microsoft.Office.Interop.Excel.Application app = new Microsoft.Office.Interop.Excel.Application();
            Microsoft.Office.Interop.Excel.Workbook wb = app.Workbooks.Open(@"D:\TestBook.xls", 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);
            wb.SaveAs(@"D:\TestBook.xlsx", Microsoft.Office.Interop.Excel.XlFileFormat.xlOpenXMLWorkbook, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Microsoft.Office.Interop.Excel.XlSaveAsAccessMode.xlExclusive, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing);
            wb.Close();
            app.Quit();

            //delete xls file
            System.IO.File.Delete(@"D:\TestBook.xls");
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }