vsto excel 判断某列都是空值或者是常量

  if (worksheet.Range["A1:A38"].SpecialCells(Excel.XlCellType.xlCellTypeConstants) != null)
                    return false;

public enum XlCellType
{
        //
        // 摘要:
        //     Cells having the same validation criteria
        xlCellTypeSameValidation = -4175,
        //
        // 摘要:
        //     Cells having validation criteria
        xlCellTypeAllValidation = -4174,
        //
        // 摘要:
        //     Cells having the same format
        xlCellTypeSameFormatConditions = -4173,
        //
        // 摘要:
        //     Cells of any format
        xlCellTypeAllFormatConditions = -4172,
        //
        // 摘要:
        //     Cells containing notes
        xlCellTypeComments = -4144,
        //
        // 摘要:
        //     Cells containing formulas
        xlCellTypeFormulas = -4123,
        //
        // 摘要:
        //     Cells containing constants
        xlCellTypeConstants = 2,
        //
        // 摘要:
        //     Empty cells
        xlCellTypeBlanks = 4,
        //
        // 摘要:
        //     The last cell in the used range
        xlCellTypeLastCell = 11,
        //
        // 摘要:
        //     All visible cells
        xlCellTypeVisible = 12
}