Make column or cells readonly with EPPlus

I am adding two WorkSheets and need to protect all columns except the one on third index.

This worked for me :)

worksheet2.Cells["A1"].LoadFromDataTable(dt_Data, true); //------load data from datatable
worksheet2.Protection.IsProtected = true; //--------Protect whole sheet
worksheet2.Column(3).Style.Locked = false; //-------Unlock 3rd column

EPPlus may be defaulting to all cells being locked, in which case you need to set the Locked attribute to false for the other columns, then set IsProtected to true.

Just thought I'd post the solution in case it helps anyone else. I had to set the entire worksheet to protected but set the Locked attribute to false for each non-Id field.

        //Content
        int i = 2;
        foreach (var zip in results)
        {
            //Set cell values
            ws.Cells["A" + i.ToString()].Value = zip.ChannelCode;
            ws.Cells["B" + i.ToString()].Value = zip.DrmTerrDesc;
            ws.Cells["C" + i.ToString()].Value = zip.IndDistrnId;
            ws.Cells["D" + i.ToString()].Value = zip.StateCode;
            ws.Cells["E" + i.ToString()].Value = zip.ZipCode;
            ws.Cells["F" + i.ToString()].Value = zip.EndDate.ToShortDateString();
            ws.Cells["G" + i.ToString()].Value = zip.EffectiveDate.ToShortDateString();
            ws.Cells["H" + i.ToString()].Value = zip.LastUpdateId;
            ws.Cells["I" + i.ToString()].Value = zip.ErrorCodes;
            ws.Cells["J" + i.ToString()].Value = zip.Status;
            ws.Cells["K" + i.ToString()].Value = zip.Id;

            //Unlock non-Id fields
            ws.Cells["A" + i.ToString()].Style.Locked = false;
            ws.Cells["B" + i.ToString()].Style.Locked = false;
            ws.Cells["C" + i.ToString()].Style.Locked = false;
            ws.Cells["D" + i.ToString()].Style.Locked = false;
            ws.Cells["E" + i.ToString()].Style.Locked = false;
            ws.Cells["F" + i.ToString()].Style.Locked = false;
            ws.Cells["G" + i.ToString()].Style.Locked = false;
            ws.Cells["H" + i.ToString()].Style.Locked = false;
            ws.Cells["I" + i.ToString()].Style.Locked = false;
            ws.Cells["J" + i.ToString()].Style.Locked = false;

            i++;
        }

        //Since we have to make the whole sheet protected and unlock each cell 
        //to allow for editing this loop is necessary
        for (int a = 65000 - i; i < 65000; i++)
        {
            //Unlock non-Id fields
            ws.Cells["A" + i.ToString()].Style.Locked = false;
            ws.Cells["B" + i.ToString()].Style.Locked = false;
            ws.Cells["C" + i.ToString()].Style.Locked = false;
            ws.Cells["D" + i.ToString()].Style.Locked = false;
            ws.Cells["E" + i.ToString()].Style.Locked = false;
            ws.Cells["F" + i.ToString()].Style.Locked = false;
            ws.Cells["G" + i.ToString()].Style.Locked = false;
            ws.Cells["H" + i.ToString()].Style.Locked = false;
            ws.Cells["I" + i.ToString()].Style.Locked = false;
            ws.Cells["J" + i.ToString()].Style.Locked = false;                
        }

        //Set worksheet protection attributes
        ws.Protection.AllowInsertRows = true;
        ws.Protection.AllowSort = true;
        ws.Protection.AllowSelectUnlockedCells = true;
        ws.Protection.AllowAutoFilter = true;
        ws.Protection.AllowInsertRows = true;
        ws.Protection.IsProtected = true;