对于Excel值,无法将类型"double"转换为"string"

Question

我正在加载一个Excel文件,如网上许多地方所示.

OpenFileDialog chooseFile = new OpenFileDialog();
            chooseFile.Filter = "Excel files (*.xls,*.xlsl)|*.xls;*.xlsx";
            if (chooseFile.ShowDialog() == System.Windows.Forms.DialogResult.OK)
            {
                selectedFileName = chooseFile.FileName;                
                textBox1.Text = selectedFileName;
                Microsoft.Office.Interop.Excel.Application excel = new Microsoft.Office.Interop.Excel.Application();
                Workbook wb = excel.Workbooks.Open(selectedFileName);                
                Sheets excelSheets = wb.Worksheets;
                string currentSheet = "Sheet 1";
                excelWorksheet = (Worksheet)excelSheets.get_Item(currentSheet);
                Range usedRange = excelWorksheet.UsedRange;
                Range lastCell = usedRange.SpecialCells(XlCellType.xlCellTypeLastCell, Type.Missing);
                lastRow = lastCell.Row;
                lastColumn = lastCell.Column;

                //release com object you won't need.
                Marshal.ReleaseComObject(excel);
                Marshal.ReleaseComObject(wb);

            }

当我尝试从具有此功能的单元格中获取单个值时出现问题:

private string getCellValue(Worksheet Sheet, int Row, int Column)
        {            
            var cellValue = (string)(Sheet.Cells[Row, Column] as Range).Value;            
            return cellValue;
        }

这段代码适用于很多单元格,但突然陷入一个提升此异常的单元格:

无法将'double'类型转换为'string'

这很奇怪,因为它完美地适用于所有其他单元格并将所有内容转换为字符串.似乎甚至没有给空白细胞带来任何麻烦.我还指定excel文件中的每个单元格都是"文本",但实际上并不知道这种行为.

也尝试了这种方式的显式转换.

private string getCellValue(Worksheet Sheet, int Row, int Column)
        {            
            string cellValue = Sheet.Cells[Row, Column].Value.ToString();
            return cellValue;
        }

现在引发的例外是:

无法对空引用执行运行时绑定

Answer 1

Text属性可用于从Cell检索文本内容.因此,您可以尝试使用该属性,如下所示:

private string getCellValue(Worksheet Sheet, int Row, int Column)
    {            
        string cellValue = Sheet.Cells[Row, Column].Text.ToString();
        return cellValue;
    }