Simple Read/Write Excel Data

In a Nav forum there was a question, how to read data from an excel document, change the data in Nav, write data back to the excel document without changing the existing cell formatting. With table ExcelBuffer and the helper assemblies delivered with Nav this cannot be done, because the Write functions e.g. SetCellValueText work with decorators.

So i developed assembly XlsLib. With that assembly read and write actions from an excel document are done very easy. The provided methods are very simple. You can read the cell values, the basic number formats and save it to table Excel Buffer. When writing only the value as is is written back to the cell. No further formatting is read or written.That can also be used, when you work with templates.

Main functions:

XlsWorksheet.GetValue(rowId, colId, value, type):
– Get a value from cell rowId/colId,
– given value is of type text,
– type is of datatype integer, can be 0-3 according option field NumberFormat in table ExcelBuffer, Type=4 means Unknown

XlsWorksheet.SetValue(rowId, colId, value):
– Sets a value in cell rowId/colId. value can be of any type.

Here is a sample code:

// variables
//  XlsWorkbook DotNet XlsLib.Workbook.'XlsLib, Version=, Culture=neutral, PublicKeyToken=38613a2311532c9a'
// XlsWorksheet DotNet XlsLib.Worksheet.'XlsLib, Version=, Culture=neutral, PublicKeyToken=38613a2311532c9a'
// value Text
// type Integer

// open excel workbook
XlsWorkbook := XlsWorkbook.Workbook('c:\temp\test.xlsx');
// select sheet 'Sheet2'
XlsWorksheet := XlsWorksheet.Worksheet(XlsWorkbook,'Sheet2');

// read cell values from row=1, column=1-3
XlsWorksheet.GetValue(1, 1, value, type); // e.g. 1234
XlsWorksheet.GetValue(1, 2, value, type); // e.g. 10.10.1990
XlsWorksheet.GetValue(1, 3, value, type); // e.g. 99.12

// Write some values
XlsWorksheet.SetValue(1, 1, 5432);  // an integer value again
XlsWorksheet.SetValue(1, 2, 010175D); // again a date value
XlsWorksheet.SetValue(1, 3, 34.45); // a decimal value

// read values again to check changes
XlsWorksheet.GetValue(1, 1, value, type);
XlsWorksheet.GetValue(1, 2, value, type);
XlsWorksheet.GetValue(1, 3, value, type);

// Save: Save to loaded file filename
// SaveAs: create a copy, save result to new file
// Close Excel App !!

// if an error occurs ...
IF XlsWorkbook.Error <> '' THEN

// release memory

You can download XlsLib here.

Hint: When downloading that file, it can be, that you have troubles using it because of security issues, e.g. dll is not visible in list of assemblies, you get an error message like “Cannot open xlslib, because one or more dependencies are not met”, methods are not visible or something else. then start windows explorer, goto folder were you copied the lib files, view file properties. if you see a notice at the bottom of the file properties window like “file is blocked because downloaded from internet, grant access?”, then click on “grant access”.



12 thoughts on “Simple Read/Write Excel Data

  1. Hi Jonathan,
    When I load this .dll into NAV (Version- 2015). I am getting this error
    “Could not load type ‘XlsLib, Version=, Culture=neutral, PublicKeyToken=38613a2311532c9a’.”

    What could be the reason.


  2. Hello Jonathan,

    I added it to the addins folder (client and server) and can see it in the development environment. But when I select XLSLIB then the methods, etc. remain empty.

    Any idea?


    1. I saw the same behaviour becaus the files were installed on both:
      C:\Program Files (x86)\Microsoft Dynamics NAV\90\RoleTailored Client\Add-ins AND on
      C:\Program Files\Microsoft Dynamics NAV\90\Service\Add-ins
      I deleted the files in de first map, problem solved.

      (Still in the testfase with this dll 🙂 )


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s