在Excel中将数据从Excel工作簿读取到ArrayList时性能低下

Question

这是一个问题描述.

条件:一般的想法是从MS Excel文件中读取大量实数,并将它们放入inro ArrayList中进行进一步处理.excel工作簿只有一个工作表.所有数字都是实数,它们存储在一列中.我逐行读取这些数字并将它们放入ArrayList中.

问题:这个过程花费了太多时间.程序花费大约2分钟来填充具有10000个元素的ArrayList.这是我的代码.我需要你的建议让它更快.但是文件的结构无法修改.它只能修改代码.请帮助我加快速度.

// Method GetExcelData opens 1 excel file, reads data row by row and adds
// it into the array of source Data Values (sourceDataValues in our case).
private void GetExcelData(string fullPath, ArrayList arrForValues)
{
    Excel.Application excelapp = new Excel.Application();
    excelapp.Visible = false;
    // to avoid appearing of Excel window on the screen
    Excel.Workbook excelappworkbook = excelapp.Workbooks.Open(
        fullPath,
        Type.Missing, Type.Missing, true, Type.Missing,
        Type.Missing, Type.Missing, Type.Missing, Type.Missing,
        Type.Missing, Type.Missing, Type.Missing, Type.Missing,
        Type.Missing, Type.Missing);
    Excel.Worksheet excelworksheet = (Excel.Worksheet)excelappworkbook.Worksheets.get_Item(1);
    Excel.Range excelcells = excelworksheet.UsedRange;
    uint rowsNum = 0;
    for (rowsNum = 1; rowsNum != excelcells.Rows.Count; rowsNum++)
    {
        arrForValues.Add((excelcells.Cells[rowsNum, 1] as Excel.Range).Value2);
    }
    excelappworkbook.Close(false, Type.Missing, Type.Missing);
    excelapp.Quit();
}

Answer 1

问题得到解决.一切都很简单.首先,我们将当前工作表的所有范围读入简单的二维数组 - worksheetValuesArray.之后,我们将该数组中的所有值放入容器中,将元素类型转换为double.以下是更正解决方案的一部分:

private void GetExcelData(string fullPath, List<double> arrForValues)
        {
            Excel.Application excelapp = new Excel.Application();
            excelapp.Visible = false;
            // to avoid appearing of Excel window on the screen
            Excel.Workbook excelappworkbook = excelapp.Workbooks.Open(
                fullPath,
                Type.Missing, Type.Missing, true, Type.Missing,
                Type.Missing, Type.Missing, Type.Missing, Type.Missing,
                Type.Missing, Type.Missing, Type.Missing, Type.Missing,
                Type.Missing, Type.Missing);
            Excel.Worksheet excelworksheet = (Excel.Worksheet)excelappworkbook.Worksheets.get_Item(1);
            Excel.Range excelcells = excelworksheet.UsedRange;
            object[,] worksheetValuesArray = excelcells.get_Value(Type.Missing);

            for (int col = 1; col < (worksheetValuesArray.GetLength(1)+1); col++)
            {
                for (int row = 1; row < (worksheetValuesArray.GetLength(0)+1); row++)
                {
                    arrForValues.Add((double) worksheetValuesArray[row, col]);
                }
            }
            excelappworkbook.Close(false, Type.Missing, Type.Missing);
            excelapp.Quit();
        }