The Syncfusion native Blazor components library offers 70+ UI and Data Viz web controls that are responsive and lightweight for building modern web apps.
.NET PDF framework is a high-performance and comprehensive library used to create, read, merge, split, secure, edit, view, and review PDF files in C#/VB.NET.
GMGeetha M Syncfusion Team August 5, 2009 11:51 AM UTC
Hi Jakub,
Thank you for your interest in Syncfusion products.
InsertColumn is designed to work if the column index falls within the UsedRange of the sheet. In other words, a new column can be inserted only within the UsedRange, otherwise, a new cell must be added. This is why the existing sheet works and a new worksheet created from scratch does not show any effect. Also, the InsertColumn method takes input in one based index, and hence to insert a column at "A", you must use sheet.InsertColumn(1);
Please try this and let me know if you have any questions.