读取 xlsx EPPlus 核心时出现 NullReference 错误

Question

我正在尝试使用 EPPlus 上传 excel 文件。我不喜欢我的 excel 文件是空的，但里面有内容。

我收到此错误： worksheet.Dimension.Rows = 'worksheet.Dimension.Rows' 抛出类型为 'System.NullReferenceException'

的异常

这一行：int rowCount = worksheet.Dimension.Rows;

[HttpPost("Excel")]
    public string UploadExcel(IFormFile file)
    {
        var filePath = Path.GetTempFileName();
        FileInfo excel = new FileInfo(filePath);

        using (ExcelPackage package = new ExcelPackage(excel))
        {
            StringBuilder sb = new StringBuilder();
            ExcelWorksheet worksheet = package.Workbook.Worksheets[file.FileName];

            int rowCount = worksheet.Dimension.Rows;
            int ColCount = worksheet.Dimension.Columns;
            bool bHeaderRow = true;
            for (int row = 1; row <= rowCount; row++)
            {
                for (int col = 1; col <= ColCount; col++)
                {
                    if (bHeaderRow)
                    {
                        sb.Append(worksheet.Cells[row, col].Value.ToString() + "\t");
                    }
                    else
                    {
                        sb.Append(worksheet.Cells[row, col].Value.ToString() + "\t");
                    }
                }
                sb.Append(Environment.NewLine);
            }
            return sb.ToString();
        }

Answer 1

您能否确认正在加载工作集？

//examine in the debugger to make sure the worksheet you want is loaded
var worksheets = package.Workbook.Worksheets.ToList();

如果这不起作用，您可以尝试其中之一吗？

var worksheet = package.Workbook.Worksheets[0];
var worksheetFirst = package.Workbook.Worksheets.First();

更新：

真正的错误是您试图用 var filePath = Path.GetTempFileName(); 读取临时文件。您需要阅读实际的 excel 文件。例如，您可以使用 Path.GetFullPath("path/to/the/excel/file.xls");

读取 xlsx EPPlus 核心时出现 NullReference 错误

NullReference Error while reading xlsx EPPlus Core

epplus

asp.net-core