In C# Winform, we created an Excel application of Microsoft.Office.Interop.Excel using Panel to configure a program to control Excel within the C# program by connecting with Panel.

Problem is if I read file for example test.xlsx using xlsxioreader C library and after that I immidietly trying to write into this file Im getting an error:

I have an already created dropdown list in cell A2. I want to use C# code to get that dropdown list from A2 and copy it to B2.

Code will open a new excel file (visible = False) and data will be entered then the excel file will be made visible(visible = True).

I got this link to automate Excel :

Read Excel sheet by using C# code with few condition.

The application generates an Excel document from several files and produces the following error
System.Runtime.InteropServices.COMException HRESULT 0x800A03EC

I’m trying to figure out how to keep the leading 0’s when exporting data from a grid to Excel, either by manipulating the value of each cell or setting a format for the entire column.
I found several suggestion to add “t” in front of the value, but this doesn’t have any effect.
The only solution I’ve found so far is to add an apostrophe in front of the value, and that works, but I really don’t want the ‘ in the excel file.