var wb = new XLWorkbook();
var ws = wb.Worksheets.Add("Protected No-Password");
ws.Protect() // On this sheet we will only allow:
.SetFormatCells() // Cell Formatting
.SetInsertColumns() // Inserting Columns
.SetDeleteColumns() // Deleting Columns
.SetDeleteRows(); // Deleting Rows
ws.Cell("A1").SetValue("Locked, No Hidden (Default):").Style.Font.SetBold().Fill.SetBackgroundColor(XLColor.Cyan);
ws.Cell("B1").Style
.Border.SetOutsideBorder(XLBorderStyleValues.Medium);
ws.Cell("A2").SetValue("Locked, Hidden:").Style.Font.SetBold().Fill.SetBackgroundColor(XLColor.Cyan);
ws.Cell("B2").Style
.Protection.SetHidden()
.Border.SetOutsideBorder(XLBorderStyleValues.Medium);
ws.Cell("A3").SetValue("Not Locked, Hidden:").Style.Font.SetBold().Fill.SetBackgroundColor(XLColor.Cyan);
ws.Cell("B3").Style
.Protection.SetLocked(false)
.Protection.SetHidden()
.Border.SetOutsideBorder(XLBorderStyleValues.Medium);
ws.Cell("A4").SetValue("Not Locked, Not Hidden:").Style.Font.SetBold().Fill.SetBackgroundColor(XLColor.Cyan);
ws.Cell("B4").Style
.Protection.SetLocked(false)
.Border.SetOutsideBorder(XLBorderStyleValues.Medium);
ws.Columns().AdjustToContents();
// Protect a sheet with a password
var protectedSheet = wb.Worksheets.Add("Protected Password = 123");
var protection = protectedSheet.Protect("123");
protection.InsertRows = true;
protection.InsertColumns = true;
wb.SaveAs("SheetProtection.xlsx");