使用更好的方式讀取 excel 數據

Question

現在，我正在從 excel 獲取數據並遍歷行並根據條件處理結果，例如將結果存儲在 object 中以供進一步處理。

excel 表約為 20 MB，記錄數接近 7000，我正在使用打開的 xml 從 excel 文件中獲取數據，如下面的代碼所示。

        string filePath = @"C:\weather-Data\DesignConditions_p.xlsx";
        using FileStream fs = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
        using SpreadsheetDocument doc = SpreadsheetDocument.Open(fs, false);
        WorkbookPart workbookPart = doc.WorkbookPart;
        SharedStringTablePart sstpart = workbookPart.GetPartsOfType<SharedStringTablePart>().First();
        SharedStringTable sst = sstpart.SharedStringTable;

        Sheet firstSheet = workbookPart.Workbook.Descendants<Sheet>().First();
        Worksheet sheet = ((WorksheetPart)workbookPart.GetPartById(firstSheet.Id)).Worksheet;

        var rows = sheet.Descendants<Row>();
        var weatherDataList = new List<WeatherStation>();
        foreach (Row row in rows.Skip(5)) // it is taking almost more than 60 minutes to process and enter into the if loop below (country.Equals("USA"))
        {
            var weatherData = new WeatherStation();
            string country = GetCellValue(filePath, "Annual", $"B{row.RowIndex.ToString()}");
            if (country.Equals("USA"))
            {
                weatherData.CountryAbbreviation = country;
                weatherData.StateAbbreviation = GetCellValue(filePath, "Annual", $"C{row.RowIndex.ToString()}");
                weatherData.Number = GetCellValue(filePath, "Annual", $"E{row.RowIndex.ToString()}");
                ......
                .......
            }
        }

在從 excel 讀取數據時，誰能指出我正確的方向以優化處理時間，我正在為這個應用程序使用.Net Core

提前致謝。

Answer 1

您可以使用“SAX”方法，這樣您可以部分讀取文件，以便處理和 IO 可能更快。：

// The SAX approach.
    static void ReadExcelFileSAX(string fileName)
    {
        using (SpreadsheetDocument spreadsheetDocument = SpreadsheetDocument.Open(fileName, false))
        {
            WorkbookPart workbookPart = spreadsheetDocument.WorkbookPart;
            WorksheetPart worksheetPart = workbookPart.WorksheetParts.First();

            OpenXmlReader reader = OpenXmlReader.Create(worksheetPart);
            string text;
            while (reader.Read())
            {
                if (reader.ElementType == typeof(CellValue))
                {
                    text = reader.GetText();
                    Console.Write(text + " ");
                }
            }
            Console.WriteLine();
            Console.ReadKey();
        }
    }

https://docs.microsoft.com/en-us/office/open-xml/how-to-parse-and-read-a-large-spreadsheet

除此之外，您可以尋找具有更快閱讀速度的庫/nuget package，因為我看不到可以更有效地調整此代碼的方法。