无法在 Excel 单元格中输入"empty"文本

Question

myExcelimage试图将"空"文本插入到空的Excel单元格中。问题：如果Excel行的长度超过35行，则所有单元格都变为空白我尝试使用 if (ExcelCell == null( 然后插入 excelcell.value == "空">

        range = xlworkSheet.UsedRange;
        rw = range.Rows.Count;
for (int row = 2; row <= rw; row++)
        {

            //if cells is empty insert error into the cells                               
            if (xlworkSheet.Cells[row, 7].Value == null)
            {
                xlworkSheet.Cells[row, 7].Value = "empty";
                xlNewSheet.Cells[row, 7].Value = "empty";
                xlNewSheet.Cells[row, 7].Interior.Color = 
                      Excel.XlRgbColor.rgbDarkOrange;
                xlworkSheet.Cells[row, 7].Interior.Color = 
                  Excel.XlRgbColor.rgbDarkOrange;
                string in0 = "t" + (String)xlworkSheet.Cells[row, 
                  7].Value.ToString();
                Console.WriteLine(in0.ToString());

            }
        }

期望在空单元格中获取空文本，但改为空白。

Answer 1

   if (string.IsNullOrWhiteSpace(xlworkSheet.Cells[row, 7].Value))
            {
                xlworkSheet.Cells[row, 7].Value = "whitespace";
                xlNewSheet.Cells[row, 7].value = "whitespace";

            }        

我导出的 Excel 单元格，所有这些空单元格实际上是空格，因此如果 (cell.value == null( 语句被忽略。