如何从 EPPlus 中捕获文件不存在的错误？

Question

我有获取 FilePath 并将所有 Excel 信息返回到列表中的函数。 我的实际问题不是功能，而是如果我的 FilePath 错误或文件不存在时无法工作的错误系统。

我尝试了一些错误基本捕获，但它不起作用并且我的程序崩溃并显示此消息：

System.NullReferenceException：'对象引用未设置为对象的实例。'

我在这里粘贴我的功能：

 public List<ImportExcelModel> GetList(string filePath)
        {
            List<ImportExcelModel> ExcelList = new List<ImportExcelModel>();
            try
            {
                ExcelPackage.LicenseContext = LicenseContext.NonCommercial;
                FileInfo fileInfo = new FileInfo(filePath);

                using (ExcelPackage excelPackage = new ExcelPackage(fileInfo))
                {
                    ExcelWorksheet worksheet = excelPackage.Workbook.Worksheets.FirstOrDefault();
                    int totalColumn = worksheet.Dimension.End.Column; // <- Error Message is print here
                    int totalRow = worksheet.Dimension.End.Row;

                    for (int row = 2; row <= totalRow; row++)
                    {
                        ImportExcelModel ll = new ImportExcelModel();
                        for (int col = 1; col <= totalColumn; col++)
                        {
                            if (col == 1) ll.DPT = worksheet.Cells[row, col].Value == null ? string.Empty : worksheet.Cells[row, col].Value.ToString();
                            if (col == 2) ll.Description = worksheet.Cells[row, col].Value == null ? string.Empty : worksheet.Cells[row, col].Value.ToString();
                            if (col == 3) ll.Conditionnement = worksheet.Cells[row, col].Value == null ? string.Empty : worksheet.Cells[row, col].Value.ToString();
                            if (col == 4) ll.StockInitial = worksheet.Cells[row, col].Value == null ? string.Empty : worksheet.Cells[row, col].Value.ToString();
                            if (col == 5) ll.Entree = worksheet.Cells[row, col].Value == null ? string.Empty : worksheet.Cells[row, col].Value.ToString();
                            if (col == 6) ll.Sortie = worksheet.Cells[row, col].Value == null ? string.Empty : worksheet.Cells[row, col].Value.ToString();
                            if (col == 7) ll.StockMini = worksheet.Cells[row, col].Value == null ? string.Empty : worksheet.Cells[row, col].Value.ToString();
                            if (col == 8) ll.StockReel = worksheet.Cells[row, col].Value == null ? string.Empty : worksheet.Cells[row, col].Value.ToString();
                            if (col == 9) ll.Localisation = worksheet.Cells[row, col].Value == null ? string.Empty : worksheet.Cells[row, col].Value.ToString();
                        }
                        ExcelList.Add(ll);
                    }
                }
                return ExcelList;
            }
            catch (Exception ex)
            {
                return ExcelList;
            }
        }

编辑：是的，如果我无法打开文件，我想要空列表

Answer 1

System.IO.File.Exists(path) 将返回真/假。使用它来确定文件是否存在