Question

I would like to deserialize all the data from the excel file to list.

I am using this code

class ExcelImport
{
    Workbook workBook;
    SharedStringTable sharedStrings;
    IEnumerable<Sheet> workSheets;
    WorksheetPart custSheet;
    WorksheetPart orderSheet;
    string FilePath;
    ExcelStorage provider;
    Stiker[] ans;
    List<Stiker> StikerList;

    public ExcelImport(string fp)
    {
        FilePath = fp;


    }




    public List<Stiker> dothejob()
    {
        using (SpreadsheetDocument document =
    SpreadsheetDocument.Open(FilePath, true))
        {
            StikerList= new List<Stiker>();
            workBook = document.WorkbookPart.Workbook;
            workSheets = workBook.Descendants<Sheet>();
            sharedStrings = document.WorkbookPart.SharedStringTablePart.SharedStringTable;
            StikerList = Stiker.LoadStiker(custSheet.Worksheet, sharedStrings);
            return StikerList;
        }
    }

But from some reson I get exception in the line:sharedStrings =
document.WorkbookPart.SharedStringTablePart.SharedStringTable;

that “Object reference not set to an instance of an object.”.

After the above saggestion found that the

if (sharedStringTablePart == null)
{
// report a problem
}

rerurn null

Any idea?

Answer 1

One of the properties in the source line will be “null” and have no value.

You’ll want to either use a debugger to figure this out (set a breakpoint on the line and hover the mouse over each property), or break down the line into separate statements. Something like:

var workBookPart = document.WorkbookPart;

if (workBookPart == null)
{
    // do something to report a problem
}

var sharedStringTablePart = workBookPart.SharedStringTablePart;
if (sharedStringTablePart == null)
{
    // report a problem
}

sharedStrings = sharedStringTablePart.SharedStringTable;

This way your code can determine at run-time if there’s an issue: this kind of “defensive” idea is usually a good idea when working with data created by some system other than your own.